sysprof/0015-sysprofd-add-support-for-unwinding-without-frame-poi.patch

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From 565ff01f20c66e35c2977a55519bd5e799a39eb3 Mon Sep 17 00:00:00 2001
From: Christian Hergert <chergert@redhat.com>
Date: Sun, 3 Nov 2024 10:41:44 -0800
Subject: [PATCH 15/18] sysprofd: add support for unwinding without frame
pointers
This provides a new sysprof-live-unwinder subprocess that runs as root to
allow accessing all processes on the system via /proc/$pid/. It is spawned
by sysprofd with various perf event FDs and a FD to write captures to.
Ideally the capture_fd is something that will naturally error if the client
application crashes (such as a socketpair() having the peer close). This
is not enforced but encouraged. Additionally, an event_fd is used to allow
the client application to signal the live-unwinder to exit.
Unwinding is performed by looking at the modules loaded into the target
pid and using libdwfl to access DWARF/CFI/etc state machinery. Stack data
does not touch the disk as it exists in a mmap buffer from perf and is
then translated into a callchain and sent to the Sysprof client.
Unwinding occurs as normal post-mortem though is improved through the use
of debuginfod to locate the appropriate symbols.
---
meson.build | 3 +-
src/meson.build | 3 +
src/sysprof-live-unwinder/main.c | 752 ++++++++++++++++++
src/sysprof-live-unwinder/meson.build | 19 +
.../sysprof-live-process.c | 505 ++++++++++++
.../sysprof-live-process.h | 50 ++
.../sysprof-live-unwinder.c | 427 ++++++++++
.../sysprof-live-unwinder.h | 79 ++
src/sysprof-live-unwinder/tests/meson.build | 35 +
.../tests/test-live-unwinder.c | 391 +++++++++
src/sysprofd/ipc-unwinder-impl.c | 247 ++++++
src/sysprofd/ipc-unwinder-impl.h | 34 +
src/sysprofd/meson.build | 10 +-
src/sysprofd/org.gnome.Sysprof3.Unwinder.xml | 23 +
src/sysprofd/sysprofd.c | 6 +-
15 files changed, 2580 insertions(+), 4 deletions(-)
create mode 100644 src/sysprof-live-unwinder/main.c
create mode 100644 src/sysprof-live-unwinder/meson.build
create mode 100644 src/sysprof-live-unwinder/sysprof-live-process.c
create mode 100644 src/sysprof-live-unwinder/sysprof-live-process.h
create mode 100644 src/sysprof-live-unwinder/sysprof-live-unwinder.c
create mode 100644 src/sysprof-live-unwinder/sysprof-live-unwinder.h
create mode 100644 src/sysprof-live-unwinder/tests/meson.build
create mode 100644 src/sysprof-live-unwinder/tests/test-live-unwinder.c
create mode 100644 src/sysprofd/ipc-unwinder-impl.c
create mode 100644 src/sysprofd/ipc-unwinder-impl.h
create mode 100644 src/sysprofd/org.gnome.Sysprof3.Unwinder.xml
diff --git a/meson.build b/meson.build
index 81e97072..9c37ebc4 100644
--- a/meson.build
+++ b/meson.build
@@ -39,12 +39,13 @@ need_glib = (need_gtk or
get_option('tools') or
get_option('tests'))
need_libsysprof = (need_gtk or
+ get_option('sysprofd') == 'bundled' or
get_option('libsysprof') or
get_option('examples') or
get_option('tools') or
get_option('tests'))
-dex_req = '0.6'
+dex_req = '0.9'
glib_req = '2.76.0'
gtk_req = '4.15'
polkit_req = '0.105'
diff --git a/src/meson.build b/src/meson.build
index f3e0c61d..9432755e 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -11,6 +11,8 @@ sysprof_version_conf.set('MINOR_VERSION', sysprof_version[1])
sysprof_version_conf.set('MICRO_VERSION', 0)
sysprof_version_conf.set('VERSION', meson.project_version())
+pkglibexecdir = join_paths(get_option('prefix'), get_option('libexecdir'))
+
subdir('libsysprof-capture')
if need_libsysprof
@@ -20,6 +22,7 @@ endif
if get_option('sysprofd') == 'bundled'
subdir('sysprofd')
+ subdir('sysprof-live-unwinder')
endif
if get_option('gtk')
diff --git a/src/sysprof-live-unwinder/main.c b/src/sysprof-live-unwinder/main.c
new file mode 100644
index 00000000..9e2733ae
--- /dev/null
+++ b/src/sysprof-live-unwinder/main.c
@@ -0,0 +1,752 @@
+/*
+ * main.c
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <stdatomic.h>
+
+#include <sys/mman.h>
+#include <sys/resource.h>
+
+#include <glib/gstdio.h>
+#include <glib-unix.h>
+
+#include <sysprof.h>
+
+#include "sysprof-live-unwinder.h"
+#include "sysprof-perf-event-stream-private.h"
+
+#define CAPTURE_BUFFER_SIZE (4096*16)
+#define N_PAGES 32
+
+#define DUMP_BYTES(_n, _b, _l) \
+ G_STMT_START { \
+ GString *str, *astr; \
+ gsize _i; \
+ g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
+ " %s = %p [%d]", #_n, _b, (gint)_l); \
+ str = g_string_sized_new (80); \
+ astr = g_string_sized_new (16); \
+ for (_i = 0; _i < _l; _i++) \
+ { \
+ if ((_i % 16) == 0) \
+ g_string_append_printf (str, "%06x: ", (guint)_i); \
+ g_string_append_printf (str, " %02x", _b[_i]); \
+ \
+ if (g_ascii_isprint(_b[_i])) \
+ g_string_append_printf (astr, " %c", _b[_i]); \
+ else \
+ g_string_append (astr, " ."); \
+ \
+ if ((_i % 16) == 15) \
+ { \
+ g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
+ "%s %s", str->str, astr->str); \
+ str->str[0] = str->len = 0; \
+ astr->str[0] = astr->len = 0; \
+ } \
+ else if ((_i % 16) == 7) \
+ { \
+ g_string_append (str, " "); \
+ g_string_append (astr, " "); \
+ } \
+ } \
+ \
+ if (_i != 16) \
+ g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
+ "%-56s %s", str->str, astr->str); \
+ \
+ g_string_free (str, TRUE); \
+ g_string_free (astr, TRUE); \
+ } G_STMT_END
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (SysprofCaptureWriter, sysprof_capture_writer_unref)
+
+typedef struct _PerfSource
+{
+ GSource gsource;
+
+ SysprofLiveUnwinder *unwinder;
+ SysprofCaptureWriter *writer;
+
+ guint64 map_size;
+ struct perf_event_mmap_page *map;
+ guint8 *map_data;
+ const guint8 *map_data_end;
+ guint64 map_data_size;
+ guint64 tail;
+
+ guint8 *buffer;
+
+ int cpu;
+ GPid self_pid;
+
+ guint stack_size;
+} PerfSource;
+
+typedef struct _PerfFDArg
+{
+ int fd;
+ int cpu;
+} PerfFDArg;
+
+SYSPROF_ALIGNED_BEGIN(8);
+typedef struct _StackRegs
+{
+ guint64 abi;
+ guint64 registers[0];
+} StackRegs
+SYSPROF_ALIGNED_END(8);
+
+SYSPROF_ALIGNED_BEGIN(8);
+typedef struct _StackUser
+{
+ guint64 size;
+ guint8 data[0];
+} StackUser
+SYSPROF_ALIGNED_END(8);
+
+static GArray *all_perf_fds;
+
+static inline void
+realign (gsize *pos,
+ gsize align)
+{
+ *pos = (*pos + align - 1) & ~(align - 1);
+}
+
+static void
+handle_event (PerfSource *source,
+ const SysprofPerfEvent *event)
+{
+ gsize offset;
+ gint64 time;
+
+ g_assert (source != NULL);
+ g_assert (event != NULL);
+
+ switch (event->header.type)
+ {
+ case PERF_RECORD_COMM:
+ offset = strlen (event->comm.comm) + 1;
+ realign (&offset, sizeof (guint64));
+ offset += sizeof (GPid) + sizeof (GPid);
+ memcpy (&time, event->comm.comm + offset, sizeof time);
+
+ if (event->comm.pid == event->comm.tid)
+ {
+ sysprof_live_unwinder_seen_process (source->unwinder,
+ time,
+ source->cpu,
+ event->comm.pid,
+ event->comm.comm);
+ }
+
+ break;
+
+ case PERF_RECORD_EXIT:
+ /* Ignore fork exits for now */
+ if (event->exit.tid != event->exit.pid)
+ break;
+
+ sysprof_live_unwinder_process_exited (source->unwinder,
+ event->exit.time,
+ source->cpu,
+ event->exit.pid);
+
+ break;
+
+ case PERF_RECORD_FORK:
+ sysprof_live_unwinder_process_forked (source->unwinder,
+ event->fork.time,
+ source->cpu,
+ event->fork.ptid,
+ event->fork.tid);
+ break;
+
+ case PERF_RECORD_LOST:
+ {
+ char message[64];
+ g_snprintf (message, sizeof message,
+ "Lost %"G_GUINT64_FORMAT" samples",
+ event->lost.lost);
+ sysprof_capture_writer_add_log (source->writer,
+ SYSPROF_CAPTURE_CURRENT_TIME,
+ source->cpu,
+ -1,
+ G_LOG_LEVEL_CRITICAL, "Sampler", message);
+ break;
+ }
+
+ case PERF_RECORD_MMAP:
+ offset = strlen (event->mmap.filename) + 1;
+ realign (&offset, sizeof (guint64));
+ offset += sizeof (GPid) + sizeof (GPid);
+ memcpy (&time, event->mmap.filename + offset, sizeof time);
+
+ sysprof_live_unwinder_track_mmap (source->unwinder,
+ time,
+ source->cpu,
+ event->mmap.pid,
+ event->mmap.addr,
+ event->mmap.addr + event->mmap.len,
+ event->mmap.pgoff,
+ 0,
+ event->mmap.filename,
+ NULL);
+
+ break;
+
+ case PERF_RECORD_MMAP2:
+ offset = strlen (event->mmap2.filename) + 1;
+ realign (&offset, sizeof (guint64));
+ offset += sizeof (GPid) + sizeof (GPid);
+ memcpy (&time, event->mmap2.filename + offset, sizeof time);
+
+ if ((event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) != 0)
+ {
+ char build_id[G_N_ELEMENTS (event->mmap2.build_id) * 2 + 1];
+ guint len = MIN (G_N_ELEMENTS (event->mmap2.build_id), event->mmap2.build_id_size);
+
+ for (guint i = 0; i < len; i++)
+ g_snprintf (&build_id[len*2], 3, "%02x", event->mmap2.build_id[i]);
+ build_id[len*2] = 0;
+
+ sysprof_live_unwinder_track_mmap (source->unwinder,
+ time,
+ source->cpu,
+ event->mmap2.pid,
+ event->mmap2.addr,
+ event->mmap2.addr + event->mmap2.len,
+ event->mmap2.pgoff,
+ event->mmap2.ino,
+ event->mmap2.filename,
+ build_id);
+ }
+ else
+ {
+ sysprof_live_unwinder_track_mmap (source->unwinder,
+ time,
+ source->cpu,
+ event->mmap2.pid,
+ event->mmap2.addr,
+ event->mmap2.addr + event->mmap2.len,
+ event->mmap2.pgoff,
+ event->mmap2.ino,
+ event->mmap2.filename,
+ NULL);
+ }
+ break;
+
+ case PERF_RECORD_READ:
+ break;
+
+ case PERF_RECORD_SAMPLE:
+ {
+ const guint8 *endptr = (const guint8 *)event + event->header.size;
+ const guint64 *ips = event->callchain.ips;
+ int n_ips = event->callchain.n_ips;
+ guint64 trace[3];
+
+ /* We always expect PERF_RECORD_SAMPLE to contain a callchain because
+ * we need that even if we sample the stack for user-space unwinding.
+ * Otherwise we lose the blended stack trace.
+ */
+ if (n_ips == 0)
+ {
+ if (event->callchain.header.misc & PERF_RECORD_MISC_KERNEL)
+ {
+ trace[0] = PERF_CONTEXT_KERNEL;
+ trace[1] = event->callchain.ip;
+ trace[2] = PERF_CONTEXT_USER;
+
+ ips = trace;
+ n_ips = 3;
+ }
+ else
+ {
+ trace[0] = PERF_CONTEXT_USER;
+ trace[1] = event->callchain.ip;
+
+ ips = trace;
+ n_ips = 2;
+ }
+ }
+
+ if (source->stack_size && source->stack_size < event->header.size)
+ {
+ guint64 dyn_size = *((const guint64 *)endptr - 1);
+ const StackUser *stack_user = (const StackUser *)(endptr - sizeof (guint64) - source->stack_size - sizeof (StackUser));
+ const StackRegs *stack_regs = (const StackRegs *)&event->callchain.ips[event->callchain.n_ips];
+ guint n_regs = ((const guint8 *)stack_user - (const guint8 *)stack_regs->registers) / sizeof (guint64);
+
+#if 0
+ g_print ("n_ips=%u stack_size=%ld dyn_size=%ld abi=%ld n_regs=%d\n",
+ n_ips, stack_user->size, dyn_size, stack_regs->abi, n_regs);
+#endif
+
+ sysprof_live_unwinder_process_sampled_with_stack (source->unwinder,
+ event->callchain.time,
+ source->cpu,
+ event->callchain.pid,
+ event->callchain.tid,
+ ips,
+ n_ips,
+ stack_user->data,
+ stack_user->size,
+ dyn_size,
+ stack_regs->abi,
+ stack_regs->registers,
+ n_regs);
+
+ break;
+ }
+
+ sysprof_live_unwinder_process_sampled (source->unwinder,
+ event->callchain.time,
+ source->cpu,
+ event->callchain.pid,
+ event->callchain.tid,
+ ips,
+ n_ips);
+
+ break;
+ }
+
+ case PERF_RECORD_THROTTLE:
+ case PERF_RECORD_UNTHROTTLE:
+ default:
+ break;
+ }
+}
+
+static gboolean
+perf_source_prepare (GSource *gsource,
+ int *timeout)
+{
+ *timeout = 50;
+ return FALSE;
+}
+
+static gboolean
+perf_source_check (GSource *gsource)
+{
+ PerfSource *source = (PerfSource *)gsource;
+ guint64 head;
+ guint64 tail;
+
+ atomic_thread_fence (memory_order_acquire);
+
+ tail = source->tail;
+ head = source->map->data_head;
+
+ if (head < tail)
+ tail = head;
+
+ return (head - tail) >= sizeof (struct perf_event_header);
+}
+
+static gboolean
+perf_source_dispatch (GSource *gsource,
+ GSourceFunc callback,
+ gpointer user_data)
+{
+ PerfSource *source = (PerfSource *)gsource;
+ guint64 n_bytes = source->map_data_size;
+ guint64 mask = n_bytes - 1;
+ guint64 head;
+ guint64 tail;
+ guint us = 0;
+ guint them = 0;
+
+ g_assert (source != NULL);
+
+ tail = source->tail;
+ head = source->map->data_head;
+
+ atomic_thread_fence (memory_order_acquire);
+
+ if (head < tail)
+ tail = head;
+
+ while ((head - tail) >= sizeof (struct perf_event_header))
+ {
+ const SysprofPerfEvent *event;
+ struct perf_event_header *header;
+ gboolean is_self = FALSE;
+
+ /* Note that:
+ *
+ * - perf events are a multiple of 64 bits
+ * - the perf event header is 64 bits
+ * - the data area is a multiple of 64 bits
+ *
+ * which means there will always be space for one header, which means we
+ * can safely dereference the size field.
+ */
+ header = (struct perf_event_header *)(gpointer)(source->map_data + (tail & mask));
+
+ if (header->size > head - tail)
+ {
+ /* The kernel did not generate a complete event.
+ * I don't think that can happen, but we may as well
+ * be paranoid.
+ */
+ g_warn_if_reached ();
+ break;
+ }
+
+ if (source->map_data + (tail & mask) + header->size > source->map_data_end)
+ {
+ guint8 *b = source->buffer;
+ gint n_before;
+ gint n_after;
+
+ n_after = (tail & mask) + header->size - n_bytes;
+ n_before = header->size - n_after;
+
+ memcpy (b, source->map_data + (tail & mask), n_before);
+ memcpy (b + n_before, source->map_data, n_after);
+
+ header = (struct perf_event_header *)(gpointer)b;
+ }
+
+ event = (SysprofPerfEvent *)header;
+
+ switch (event->header.type)
+ {
+ default:
+ case PERF_RECORD_COMM:
+ case PERF_RECORD_EXIT:
+ case PERF_RECORD_FORK:
+ case PERF_RECORD_MMAP:
+ case PERF_RECORD_MMAP2:
+ break;
+
+ case PERF_RECORD_SAMPLE:
+ is_self = event->callchain.pid == source->self_pid;
+ break;
+
+ case PERF_RECORD_READ:
+ case PERF_RECORD_THROTTLE:
+ case PERF_RECORD_UNTHROTTLE:
+ goto skip_callback;
+
+ case PERF_RECORD_LOST:
+ break;
+ }
+
+ handle_event (source, event);
+
+ us += is_self;
+ them += !is_self;
+
+ skip_callback:
+ tail += header->size;
+ }
+
+ source->tail = tail;
+
+ atomic_thread_fence (memory_order_seq_cst);
+
+ source->map->data_tail = tail;
+
+ sysprof_capture_writer_flush (source->writer);
+
+ return G_SOURCE_CONTINUE;
+}
+
+static void
+perf_source_finalize (GSource *gsource)
+{
+ PerfSource *source = (PerfSource *)gsource;
+
+ if (source->map != NULL &&
+ (gpointer)source->map != MAP_FAILED)
+ munmap ((gpointer)source->map, source->map_size);
+
+ g_clear_pointer (&source->buffer, g_free);
+ g_clear_pointer (&source->writer, sysprof_capture_writer_unref);
+ g_clear_object (&source->unwinder);
+
+ source->map = NULL;
+ source->map_data = NULL;
+ source->map_data_end = NULL;
+ source->map_data_size = 0;
+ source->map_size = 0;
+ source->tail = 0;
+}
+
+static const GSourceFuncs source_funcs = {
+ .prepare = perf_source_prepare,
+ .check = perf_source_check,
+ .dispatch = perf_source_dispatch,
+ .finalize = perf_source_finalize,
+};
+
+static gboolean
+perf_source_init (PerfSource *source,
+ int fd,
+ SysprofLiveUnwinder *unwinder,
+ SysprofCaptureWriter *writer,
+ int cpu,
+ int stack_size,
+ GError **error)
+{
+ gsize map_size;
+ guint8 *map;
+
+ g_assert (source != NULL);
+ g_assert (writer != NULL);
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (unwinder));
+ g_assert (fd > STDERR_FILENO);
+
+ map_size = N_PAGES * sysprof_getpagesize () + sysprof_getpagesize ();
+ map = mmap (NULL, map_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+
+ if ((gpointer)map == MAP_FAILED)
+ {
+ int errsv = errno;
+ g_set_error_literal (error,
+ G_FILE_ERROR,
+ g_file_error_from_errno (errsv),
+ g_strerror (errsv));
+ return FALSE;
+ }
+
+ source->writer = sysprof_capture_writer_ref (writer);
+ source->unwinder = g_object_ref (unwinder);
+ source->buffer = g_malloc (map_size);
+ source->map_size = map_size;
+ source->map = (gpointer)map;
+ source->map_data = map + sysprof_getpagesize ();
+ source->map_data_size = N_PAGES * sysprof_getpagesize ();
+ source->map_data_end = source->map_data + source->map_data_size;
+ source->tail = 0;
+ source->self_pid = getpid ();
+ source->cpu = cpu;
+ source->stack_size = stack_size;
+
+ g_source_add_unix_fd ((GSource *)source, fd, G_IO_IN);
+
+ return TRUE;
+}
+
+static GSource *
+perf_source_new (int perf_fd,
+ SysprofLiveUnwinder *unwinder,
+ SysprofCaptureWriter *writer,
+ int cpu,
+ int stack_size,
+ GError **error)
+{
+ GSource *source;
+
+ if (perf_fd <= STDERR_FILENO)
+ {
+ g_set_error (error,
+ G_FILE_ERROR,
+ G_FILE_ERROR_BADF,
+ "Invalid file-descriptor for perf event stream");
+ return NULL;
+ }
+
+ source = g_source_new ((GSourceFuncs *)&source_funcs, sizeof (PerfSource));
+ g_source_set_static_name (source, "[perf-event-stream]");
+ g_source_set_priority (source, G_PRIORITY_HIGH);
+
+ if (!perf_source_init ((PerfSource *)source, perf_fd, unwinder, writer, cpu, stack_size, error))
+ g_clear_pointer (&source, g_source_unref);
+
+ return source;
+}
+
+static void
+clear_perf_fd (gpointer data)
+{
+ PerfFDArg *arg = data;
+
+ if (arg->fd > STDERR_FILENO)
+ {
+ close (arg->fd);
+ arg->fd = -1;
+ }
+}
+
+static gboolean
+perf_fd_callback (const char *option_name,
+ const char *option_value,
+ gpointer data,
+ GError **error)
+{
+ PerfFDArg arg = {-1, -1};
+
+ if (sscanf (option_value, "%d:%d", &arg.fd, &arg.cpu) < 1)
+ {
+ g_set_error (error,
+ G_FILE_ERROR,
+ G_FILE_ERROR_BADF,
+ "--perf-fd must be in the format FD or FD:CPU_NUMBER");
+ return FALSE;
+ }
+
+ if (arg.fd <= STDERR_FILENO)
+ {
+ g_set_error (error,
+ G_FILE_ERROR,
+ G_FILE_ERROR_BADF,
+ "--perf-fd must be >= %d",
+ STDERR_FILENO);
+ return FALSE;
+ }
+
+ g_array_append_val (all_perf_fds, arg);
+
+ return TRUE;
+}
+
+static void
+bump_to_max_fd_limit (void)
+{
+ struct rlimit limit;
+
+ if (getrlimit (RLIMIT_NOFILE, &limit) == 0)
+ {
+ limit.rlim_cur = limit.rlim_max;
+
+ if (setrlimit (RLIMIT_NOFILE, &limit) != 0)
+ g_warning ("Failed to set FD limit to %"G_GSSIZE_FORMAT"",
+ (gssize)limit.rlim_max);
+ else
+ g_debug ("Set RLIMIT_NOFILE to %"G_GSSIZE_FORMAT"",
+ (gssize)limit.rlim_max);
+ }
+}
+
+static gboolean
+exit_callback (gpointer user_data)
+{
+ g_main_loop_quit (user_data);
+ return G_SOURCE_REMOVE;
+}
+
+int
+main (int argc,
+ char *argv[])
+{
+ g_autoptr(SysprofCaptureWriter) writer = NULL;
+ g_autoptr(SysprofLiveUnwinder) unwinder = NULL;
+ g_autoptr(GOptionContext) context = NULL;
+ g_autoptr(GMainLoop) main_loop = NULL;
+ g_autoptr(GError) error = NULL;
+ g_autofd int capture_fd = -1;
+ g_autofd int kallsyms_fd = -1;
+ g_autofd int event_fd = -1;
+ int stack_size = 0;
+ const GOptionEntry entries[] = {
+ { "perf-fd", 0, 0, G_OPTION_ARG_CALLBACK, perf_fd_callback, "A file-descriptor to the perf event stream", "FD[:CPU]" },
+ { "capture-fd", 0, 0, G_OPTION_ARG_INT, &capture_fd, "A file-descriptor to the sysprof capture", "FD" },
+ { "event-fd", 0, 0, G_OPTION_ARG_INT, &event_fd, "A file-descriptor to an event-fd used to notify unwinder should exit", "FD" },
+ { "kallsyms", 'k', 0, G_OPTION_ARG_INT, &kallsyms_fd, "Bundle kallsyms provided from passed FD", "FD" },
+ { "stack-size", 's', 0, G_OPTION_ARG_INT, &stack_size, "Size of stacks being recorded", "STACK_SIZE" },
+ { 0 }
+ };
+
+ main_loop = g_main_loop_new (NULL, FALSE);
+
+ all_perf_fds = g_array_new (FALSE, FALSE, sizeof (PerfFDArg));
+ g_array_set_clear_func (all_perf_fds, clear_perf_fd);
+
+ context = g_option_context_new ("- translate perf event stream to sysprof");
+ g_option_context_add_main_entries (context, entries, NULL);
+ g_option_context_set_summary (context, "\
+ This tool is used by sysprofd to process incoming perf events that\n\
+ include a copy of the stack and register state to the Sysprof capture\n\
+ format.\n\
+\n\
+ It should be provided two file-descriptors. One is for the perf-event\n\
+ stream and one is for the Sysprof capture writer.\n\
+\n\
+ Events that are not related to stack traces will also be passed along to\n\
+ to the capture in the standard Sysprof capture format. That includes mmap\n\
+ events, process information, and more.\n\
+\n\
+Examples:\n\
+\n\
+ # FD 3 contains perf_event stream for CPU 1\n\
+ sysprof-translate --perf-fd=3:1 --capture-fd=4");
+
+ if (!g_option_context_parse (context, &argc, &argv, &error))
+ {
+ g_printerr ("%s\n", error->message);
+ return EXIT_FAILURE;
+ }
+
+ if (capture_fd <= STDERR_FILENO)
+ {
+ g_printerr ("--capture-fd must be > %d\n", STDERR_FILENO);
+ return EXIT_FAILURE;
+ }
+
+ writer = sysprof_capture_writer_new_from_fd (g_steal_fd (&capture_fd), CAPTURE_BUFFER_SIZE);
+
+ if (all_perf_fds->len == 0)
+ {
+ g_printerr ("You must secify at least one --perf-fd\n");
+ return EXIT_FAILURE;
+ }
+
+ bump_to_max_fd_limit ();
+
+ unwinder = sysprof_live_unwinder_new (writer, g_steal_fd (&kallsyms_fd));
+
+ for (guint i = 0; i < all_perf_fds->len; i++)
+ {
+ const PerfFDArg *arg = &g_array_index (all_perf_fds, PerfFDArg, i);
+ g_autoptr(GSource) perf_source = NULL;
+
+ if (!(perf_source = perf_source_new (arg->fd, unwinder, writer, arg->cpu, stack_size, &error)))
+ {
+ g_printerr ("Failed to initialize perf event stream: %s\n",
+ error->message);
+ return EXIT_FAILURE;
+ }
+
+ g_source_attach (perf_source, NULL);
+ }
+
+ if (event_fd != -1)
+ {
+ g_autoptr(GSource) exit_source = g_unix_fd_source_new (event_fd, G_IO_IN);
+
+ g_source_set_callback (exit_source,
+ exit_callback,
+ g_main_loop_ref (main_loop),
+ (GDestroyNotify) g_main_loop_unref);
+ g_source_attach (exit_source, NULL);
+ }
+
+ g_main_loop_run (main_loop);
+
+ g_clear_pointer (&all_perf_fds, g_array_unref);
+
+ return EXIT_SUCCESS;
+}
diff --git a/src/sysprof-live-unwinder/meson.build b/src/sysprof-live-unwinder/meson.build
new file mode 100644
index 00000000..8cef7106
--- /dev/null
+++ b/src/sysprof-live-unwinder/meson.build
@@ -0,0 +1,19 @@
+sysprof_live_unwinder_deps = [
+ libsysprof_static_dep,
+ dependency('libdw'),
+]
+
+sysprof_live_unwinder_sources = [
+ 'sysprof-live-process.c',
+ 'sysprof-live-unwinder.c',
+ 'main.c',
+]
+
+sysprof_live_unwinder = executable('sysprof-live-unwinder', sysprof_live_unwinder_sources,
+ dependencies: sysprof_live_unwinder_deps,
+ c_args: release_flags,
+ install: true,
+ install_dir: pkglibexecdir,
+)
+
+subdir('tests')
diff --git a/src/sysprof-live-unwinder/sysprof-live-process.c b/src/sysprof-live-unwinder/sysprof-live-process.c
new file mode 100644
index 00000000..7932048b
--- /dev/null
+++ b/src/sysprof-live-unwinder/sysprof-live-process.c
@@ -0,0 +1,505 @@
+/*
+ * sysprof-live-pid.c
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <sys/wait.h>
+#include <sys/syscall.h>
+
+/* Workaround for linux/fcntl.h also including the
+ * flock definitions in addition to libc.
+ */
+#ifndef _LINUX_FCNTL_H
+# define _LINUX_FCNTL_H
+# include <linux/pidfd.h>
+# undef _LINUX_FCNTL_H
+#else
+# include <linux/pidfd.h>
+#endif
+
+#include <linux/perf_event.h>
+
+#include <libelf.h>
+#include <elfutils/libdwelf.h>
+#include <elfutils/libdwfl.h>
+
+#include <glib/gstdio.h>
+
+#include <sysprof-capture.h>
+
+#include "sysprof-live-process.h"
+
+typedef struct _SysprofLiveProcess
+{
+ Dwfl_Callbacks callbacks;
+ Dwfl *dwfl;
+ Elf *elf;
+ char *root;
+ GPid pid;
+ int fd;
+} SysprofLiveProcess;
+
+typedef struct _SysprofUnwinder
+{
+ SysprofLiveProcess *process;
+ const guint8 *stack;
+ gsize stack_len;
+ const guint64 *registers;
+ guint n_registers;
+ guint64 *addresses;
+ guint addresses_capacity;
+ guint addresses_len;
+ guint64 abi;
+ guint64 sp;
+ guint64 pc;
+ guint64 base_address;
+ GPid pid;
+ GPid tid;
+} SysprofUnwinder;
+
+static SysprofUnwinder *current_unwinder;
+
+static inline GPid
+sysprof_unwinder_next_thread (Dwfl *dwfl,
+ void *user_data,
+ void **thread_argp)
+{
+ SysprofUnwinder *unwinder = current_unwinder;
+
+ if (*thread_argp == NULL)
+ {
+ *thread_argp = unwinder;
+ return unwinder->tid;
+ }
+
+ return 0;
+}
+
+static inline bool
+sysprof_unwinder_get_thread (Dwfl *dwfl,
+ pid_t tid,
+ void *user_data,
+ void **thread_argp)
+{
+ SysprofUnwinder *unwinder = current_unwinder;
+
+ if (unwinder->tid == tid)
+ {
+ *thread_argp = unwinder;
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+static inline bool
+copy_word (const guint8 *data,
+ Dwarf_Word *result,
+ guint64 abi)
+{
+ if (abi == PERF_SAMPLE_REGS_ABI_64)
+ memcpy (result, data, sizeof (guint64));
+ else if (abi == PERF_SAMPLE_REGS_ABI_32)
+ memcpy (result, data, sizeof (guint32));
+ else
+ g_assert_not_reached ();
+
+ return TRUE;
+}
+
+static inline bool
+sysprof_unwinder_memory_read (Dwfl *dwfl,
+ Dwarf_Addr addr,
+ Dwarf_Word *result,
+ void *user_data)
+{
+ SysprofUnwinder *unwinder = current_unwinder;
+
+ if (addr < unwinder->base_address || addr - unwinder->base_address >= unwinder->stack_len)
+ {
+ Dwfl_Module *module = NULL;
+ Elf_Data *data = NULL;
+ Elf_Scn *section = NULL;
+ Dwarf_Addr bias;
+
+ if (!(module = dwfl_addrmodule (dwfl, addr)) ||
+ !(section = dwfl_module_address_section (module, &addr, &bias)) ||
+ !(data = elf_getdata (section, NULL)))
+ return FALSE;
+
+ if (data->d_buf && data->d_size > addr)
+ return copy_word ((guint8 *)data->d_buf + addr, result, unwinder->abi);
+
+ return FALSE;
+ }
+
+ return copy_word (&unwinder->stack[addr - unwinder->base_address], result, unwinder->abi);
+}
+
+static inline bool
+sysprof_unwinder_set_initial_registers (Dwfl_Thread *thread,
+ void *user_data)
+{
+ SysprofUnwinder *unwinder = current_unwinder;
+
+ dwfl_thread_state_register_pc (thread, unwinder->pc);
+
+ if (unwinder->abi == PERF_SAMPLE_REGS_ABI_64)
+ {
+ static const int regs_x86_64[] = {0, 3, 2, 1, 4, 5, 6, 7/*sp*/, 9, 10, 11, 12, 13, 14, 15, 16, 8/*ip*/};
+
+ for (int i = 0; i < G_N_ELEMENTS (regs_x86_64); i++)
+ {
+ int j = regs_x86_64[i];
+
+ dwfl_thread_state_registers (thread, i, 1, &unwinder->registers[j]);
+ }
+ }
+ else if (unwinder->abi == PERF_SAMPLE_REGS_ABI_32)
+ {
+ static const int regs_i386[] = {0, 2, 3, 1, 7/*sp*/, 6, 4, 5, 8/*ip*/};
+
+ for (int i = 0; i < G_N_ELEMENTS (regs_i386); i++)
+ {
+ int j = regs_i386[i];
+
+ dwfl_thread_state_registers (thread, i, 1, &unwinder->registers[j]);
+ }
+ }
+
+ return TRUE;
+}
+
+static const Dwfl_Thread_Callbacks thread_callbacks = {
+ sysprof_unwinder_next_thread,
+ sysprof_unwinder_get_thread,
+ sysprof_unwinder_memory_read,
+ sysprof_unwinder_set_initial_registers,
+ NULL, /* detach */
+ NULL, /* thread_detach */
+};
+
+static inline int
+sysprof_unwinder_frame_cb (Dwfl_Frame *frame,
+ void *user_data)
+{
+ SysprofUnwinder *unwinder = current_unwinder;
+ Dwarf_Addr pc;
+ Dwarf_Addr sp;
+ bool is_activation;
+ guint8 sp_register_id;
+
+ if (unwinder->addresses_len == unwinder->addresses_capacity)
+ return DWARF_CB_ABORT;
+
+ if (!dwfl_frame_pc (frame, &pc, &is_activation))
+ return DWARF_CB_ABORT;
+
+ if (unwinder->abi == PERF_SAMPLE_REGS_ABI_64)
+ sp_register_id = 7;
+ else if (unwinder->abi == PERF_SAMPLE_REGS_ABI_32)
+ sp_register_id = 4;
+ else
+ return DWARF_CB_ABORT;
+
+ if (dwfl_frame_reg (frame, sp_register_id, &sp) < 0)
+ return DWARF_CB_ABORT;
+
+ unwinder->addresses[unwinder->addresses_len++] = pc;
+
+ return DWARF_CB_OK;
+}
+
+static inline guint
+sysprof_unwind (SysprofLiveProcess *self,
+ Dwfl *dwfl,
+ Elf *elf,
+ GPid pid,
+ GPid tid,
+ guint64 abi,
+ const guint64 *registers,
+ guint n_registers,
+ const guint8 *stack,
+ gsize stack_len,
+ guint64 *addresses,
+ guint n_addresses)
+{
+#if defined(__x86_64__) || defined(__i386__)
+ SysprofUnwinder unwinder;
+
+ g_assert (dwfl != NULL);
+ g_assert (elf != NULL);
+
+ /* Ignore anything byt 32/64 defined abi */
+ if (!(abi == PERF_SAMPLE_REGS_ABI_32 || abi == PERF_SAMPLE_REGS_ABI_64))
+ return 0;
+
+ /* Make sure we have registers/stack to work with */
+ if (registers == NULL || stack == NULL || stack_len == 0)
+ return 0;
+
+ /* 9 registers on 32-bit x86, 17 on 64-bit x86_64 */
+ if (!((abi == PERF_SAMPLE_REGS_ABI_32 && n_registers == 9) ||
+ (abi == PERF_SAMPLE_REGS_ABI_64 && n_registers == 17)))
+ return 0;
+
+ unwinder.process = self;
+ unwinder.sp = registers[7];
+ unwinder.pc = registers[8];
+ unwinder.base_address = unwinder.sp;
+ unwinder.addresses = addresses;
+ unwinder.addresses_capacity = n_addresses;
+ unwinder.addresses_len = 0;
+ unwinder.pid = pid;
+ unwinder.tid = tid;
+ unwinder.stack = stack;
+ unwinder.stack_len = stack_len;
+ unwinder.abi = abi;
+ unwinder.registers = registers;
+ unwinder.n_registers = n_registers;
+
+ current_unwinder = &unwinder;
+ dwfl_getthread_frames (dwfl, tid, sysprof_unwinder_frame_cb, NULL);
+ current_unwinder = NULL;
+
+ return unwinder.addresses_len;
+#else
+ return 0;
+#endif
+}
+
+G_GNUC_NO_INLINE static int
+_pidfd_open (int pid,
+ unsigned flags)
+{
+ int pidfd = syscall (SYS_pidfd_open, pid, flags);
+
+ if (pidfd != -1)
+ {
+ int old_flags = fcntl (pidfd, F_GETFD);
+
+ if (old_flags != -1)
+ fcntl (pidfd, F_SETFD, old_flags | FD_CLOEXEC);
+ }
+
+ return pidfd;
+}
+
+static int
+sysprof_live_process_find_elf (Dwfl_Module *module,
+ void **user_data,
+ const char *module_name,
+ Dwarf_Addr base_addr,
+ char **filename,
+ Elf **elf)
+{
+ g_assert (current_unwinder != NULL);
+ g_assert (current_unwinder->process != NULL);
+
+ *filename = NULL;
+ *elf = NULL;
+
+ if (module_name[0] == '/')
+ {
+ g_autofree char *path = g_strdup_printf ("/proc/%u/root/%s", current_unwinder->pid, module_name);
+ g_autofd int fd = open (path, O_RDONLY | O_CLOEXEC);
+
+ if (fd != -1)
+ {
+ *elf = dwelf_elf_begin (fd);
+ return g_steal_fd (&fd);
+ }
+ }
+
+ return dwfl_linux_proc_find_elf (module, user_data, module_name, base_addr, filename, elf);
+}
+
+static int
+sysprof_live_process_find_debuginfo (Dwfl_Module *module,
+ void **user_data,
+ const char *module_name,
+ Dwarf_Addr base_addr,
+ const char *file_name,
+ const char *debuglink_file,
+ GElf_Word debuglink_crc,
+ char **debuginfo_file_name)
+{
+ return -1;
+}
+
+SysprofLiveProcess *
+sysprof_live_process_new (GPid pid)
+{
+ SysprofLiveProcess *live_process;
+
+ live_process = g_atomic_rc_box_new0 (SysprofLiveProcess);
+ live_process->pid = pid;
+ live_process->fd = _pidfd_open (pid, 0);
+ live_process->root = g_strdup_printf ("/proc/%u/root/", pid);
+ live_process->callbacks.find_elf = sysprof_live_process_find_elf;
+ live_process->callbacks.find_debuginfo = sysprof_live_process_find_debuginfo;
+ live_process->callbacks.debuginfo_path = g_new0 (char *, 2);
+ live_process->callbacks.debuginfo_path[0] = g_build_filename (live_process->root, "usr/lib/debug", NULL);
+
+ return live_process;
+}
+
+SysprofLiveProcess *
+sysprof_live_process_ref (SysprofLiveProcess *live_process)
+{
+ g_return_val_if_fail (live_process != NULL, NULL);
+
+ return g_atomic_rc_box_acquire (live_process);
+}
+
+static void
+sysprof_live_process_finalize (gpointer data)
+{
+ SysprofLiveProcess *live_process = data;
+
+ if (live_process->fd != -1)
+ {
+ close (live_process->fd);
+ live_process->fd = -1;
+ }
+
+ g_clear_pointer (&live_process->elf, elf_end);
+ g_clear_pointer (&live_process->dwfl, dwfl_end);
+ g_clear_pointer (&live_process->root, g_free);
+ g_clear_pointer (&live_process->callbacks.debuginfo_path, g_free);
+}
+
+void
+sysprof_live_process_unref (SysprofLiveProcess *live_process)
+{
+ g_return_if_fail (live_process != NULL);
+
+ g_atomic_rc_box_release_full (live_process, sysprof_live_process_finalize);
+}
+
+gboolean
+sysprof_live_process_is_active (SysprofLiveProcess *self)
+{
+ g_return_val_if_fail (self != NULL, FALSE);
+
+ return self->fd > -1;
+}
+
+static Dwfl *
+sysprof_live_process_get_dwfl (SysprofLiveProcess *self)
+{
+ g_assert (self != NULL);
+
+ if G_UNLIKELY (self->dwfl == NULL)
+ {
+ self->dwfl = dwfl_begin (&self->callbacks);
+
+ dwfl_linux_proc_report (self->dwfl, self->pid);
+ dwfl_report_end (self->dwfl, NULL, NULL);
+
+ if (self->fd > -1)
+ {
+ char path[64];
+ g_autofd int exe_fd = -1;
+
+ g_snprintf (path, sizeof path, "/proc/%u/exe", self->pid);
+ exe_fd = open (path, O_RDONLY);
+
+ if (exe_fd > -1)
+ {
+ self->elf = elf_begin (exe_fd, ELF_C_READ_MMAP, NULL);
+
+ if (self->elf != NULL)
+ dwfl_attach_state (self->dwfl, self->elf, self->pid, &thread_callbacks, self);
+ }
+ }
+ else
+ g_warning ("Attmpting to load exited process\n");
+ }
+
+ return self->dwfl;
+}
+
+guint
+sysprof_live_process_unwind (SysprofLiveProcess *self,
+ GPid tid,
+ guint64 abi,
+ const guint8 *stack,
+ gsize stack_len,
+ const guint64 *registers,
+ guint n_registers,
+ guint64 *addresses,
+ guint n_addresses)
+{
+#if defined(__x86_64__) || defined(__i386__)
+ Dwfl *dwfl;
+
+ g_assert (self != NULL);
+ g_assert (stack != NULL);
+ g_assert (registers != NULL);
+ g_assert (addresses != NULL);
+
+ if (!sysprof_live_process_is_active (self))
+ return 0;
+
+ if (!(dwfl = sysprof_live_process_get_dwfl (self)))
+ return 0;
+
+ if (self->elf == NULL)
+ return 0;
+
+ g_assert (self->dwfl != NULL);
+ g_assert (self->elf != NULL);
+
+ return sysprof_unwind (self,
+ self->dwfl,
+ self->elf,
+ self->pid,
+ tid,
+ abi,
+ registers,
+ n_registers,
+ stack,
+ stack_len,
+ addresses,
+ n_addresses);
+#else
+ return 0;
+#endif
+}
+
+void
+sysprof_live_process_add_map (SysprofLiveProcess *self,
+ guint64 begin,
+ guint64 end,
+ guint64 offset,
+ guint64 inode,
+ const char *filename)
+{
+ g_assert (self != NULL);
+
+ /* We'll reparse VMAs on next use */
+ g_clear_pointer (&self->dwfl, dwfl_end);
+ g_clear_pointer (&self->elf, elf_end);
+}
diff --git a/src/sysprof-live-unwinder/sysprof-live-process.h b/src/sysprof-live-unwinder/sysprof-live-process.h
new file mode 100644
index 00000000..e2601a5b
--- /dev/null
+++ b/src/sysprof-live-unwinder/sysprof-live-process.h
@@ -0,0 +1,50 @@
+/*
+ * sysprof-live-pid.h
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+typedef struct _SysprofLiveProcess SysprofLiveProcess;
+
+SysprofLiveProcess *sysprof_live_process_new (GPid pid);
+SysprofLiveProcess *sysprof_live_process_ref (SysprofLiveProcess *self);
+void sysprof_live_process_unref (SysprofLiveProcess *self);
+gboolean sysprof_live_process_is_active (SysprofLiveProcess *self);
+void sysprof_live_process_add_map (SysprofLiveProcess *self,
+ guint64 begin,
+ guint64 end,
+ guint64 offset,
+ guint64 inode,
+ const char *filename);
+guint sysprof_live_process_unwind (SysprofLiveProcess *self,
+ GPid tid,
+ guint64 abi,
+ const guint8 *stack,
+ gsize stack_len,
+ const guint64 *registers,
+ guint n_registers,
+ guint64 *addresses,
+ guint n_addresses);
+
+G_END_DECLS
diff --git a/src/sysprof-live-unwinder/sysprof-live-unwinder.c b/src/sysprof-live-unwinder/sysprof-live-unwinder.c
new file mode 100644
index 00000000..c3b954b2
--- /dev/null
+++ b/src/sysprof-live-unwinder/sysprof-live-unwinder.c
@@ -0,0 +1,427 @@
+/*
+ * sysprof-live-unwinder.c
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <linux/perf_event.h>
+
+#include <glib/gstdio.h>
+
+#include "sysprof-live-process.h"
+#include "sysprof-live-unwinder.h"
+#include "sysprof-maps-parser-private.h"
+
+struct _SysprofLiveUnwinder
+{
+ GObject parent_instance;
+ SysprofCaptureWriter *writer;
+ GHashTable *live_pids_by_pid;
+};
+
+G_DEFINE_FINAL_TYPE (SysprofLiveUnwinder, sysprof_live_unwinder, G_TYPE_OBJECT)
+
+enum {
+ CLOSED,
+ N_SIGNALS
+};
+
+static guint signals[N_SIGNALS];
+
+static char *
+sysprof_live_unwinder_read_file (SysprofLiveUnwinder *self,
+ const char *path,
+ gboolean insert_into_capture)
+{
+ gint64 when = SYSPROF_CAPTURE_CURRENT_TIME;
+ char *contents = NULL;
+ gsize len = 0;
+ gsize offset = 0;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+ g_assert (self->writer != NULL);
+
+ if (!g_file_get_contents (path, &contents, &len, NULL))
+ return NULL;
+
+ if (insert_into_capture)
+ {
+ while (len > 0)
+ {
+ gsize this_write = MIN (len, 4096*4);
+
+ if (!sysprof_capture_writer_add_file (self->writer,
+ when,
+ -1,
+ -1,
+ path,
+ this_write == len,
+ (const guint8 *)&contents[offset], this_write))
+ break;
+
+ len -= this_write;
+ offset += this_write;
+ }
+ }
+
+ return contents;
+}
+
+static char *
+sysprof_live_unwinder_read_pid_file (SysprofLiveUnwinder *self,
+ GPid pid,
+ const char *path_part,
+ gboolean insert_into_capture)
+{
+ g_autofree char *path = NULL;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+ g_assert (self->writer != NULL);
+
+ path = g_strdup_printf ("/proc/%d/%s", pid, path_part);
+
+ return sysprof_live_unwinder_read_file (self, path, insert_into_capture);
+}
+
+static SysprofLiveProcess *
+sysprof_live_unwinder_find_pid (SysprofLiveUnwinder *self,
+ GPid pid,
+ gboolean send_comm)
+{
+ SysprofLiveProcess *live_pid;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+
+ if (pid < 0)
+ return NULL;
+
+ if (!(live_pid = g_hash_table_lookup (self->live_pids_by_pid, GINT_TO_POINTER (pid))))
+ {
+ gint64 now = SYSPROF_CAPTURE_CURRENT_TIME;
+
+ live_pid = sysprof_live_process_new (pid);
+
+ g_hash_table_replace (self->live_pids_by_pid, GINT_TO_POINTER (pid), live_pid);
+
+ if (send_comm)
+ {
+ g_autofree char *path = g_strdup_printf ("/proc/%d/comm", pid);
+ g_autofree char *comm = NULL;
+ gsize len;
+
+ if (g_file_get_contents (path, &comm, &len, NULL))
+ {
+ g_autofree char *tmp = comm;
+ comm = g_strstrip (g_utf8_make_valid (tmp, len));
+ sysprof_capture_writer_add_process (self->writer, now, -1, pid, comm);
+ }
+ }
+
+ if (sysprof_live_process_is_active (live_pid))
+ {
+ g_autofree char *mountinfo = sysprof_live_unwinder_read_pid_file (self, pid, "mountinfo", TRUE);
+ g_autofree char *maps = sysprof_live_unwinder_read_pid_file (self, pid, "maps", FALSE);
+
+ if (maps != NULL)
+ {
+ SysprofMapsParser maps_parser;
+ guint64 begin, end, offset, inode;
+ char *filename;
+
+ sysprof_maps_parser_init (&maps_parser, maps, -1);
+
+ while (sysprof_maps_parser_next (&maps_parser, &begin, &end, &offset, &inode, &filename))
+ {
+ sysprof_live_process_add_map (live_pid, begin, end, offset, inode, filename);
+ sysprof_capture_writer_add_map (self->writer, now, -1, pid,
+ begin, end, offset,
+ inode, filename);
+ g_free (filename);
+ }
+ }
+ }
+ }
+
+ return live_pid;
+}
+
+static void
+sysprof_live_unwinder_mine_pids (SysprofLiveUnwinder *self)
+{
+ g_autoptr(GDir) dir = NULL;
+ const char *name;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+ g_assert (self->writer != NULL);
+
+ if (!(dir = g_dir_open ("/proc", 0, NULL)))
+ return;
+
+ while ((name = g_dir_read_name (dir)))
+ {
+ GPid pid;
+
+ if (!g_ascii_isdigit (*name))
+ continue;
+
+ if (!(pid = atoi (name)))
+ continue;
+
+ sysprof_live_unwinder_find_pid (self, pid, TRUE);
+ }
+}
+
+static void
+sysprof_live_unwinder_finalize (GObject *object)
+{
+ SysprofLiveUnwinder *self = (SysprofLiveUnwinder *)object;
+
+ g_clear_pointer (&self->writer, sysprof_capture_writer_unref);
+ g_clear_pointer (&self->live_pids_by_pid, g_hash_table_unref);
+
+ G_OBJECT_CLASS (sysprof_live_unwinder_parent_class)->finalize (object);
+}
+
+static void
+sysprof_live_unwinder_class_init (SysprofLiveUnwinderClass *klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+ object_class->finalize = sysprof_live_unwinder_finalize;
+
+ signals[CLOSED] =
+ g_signal_new ("closed",
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ 0,
+ NULL, NULL,
+ NULL,
+ G_TYPE_NONE, 0);
+}
+
+static void
+sysprof_live_unwinder_init (SysprofLiveUnwinder *self)
+{
+ self->live_pids_by_pid = g_hash_table_new_full (NULL,
+ NULL,
+ NULL,
+ (GDestroyNotify)sysprof_live_process_unref);
+}
+
+SysprofLiveUnwinder *
+sysprof_live_unwinder_new (SysprofCaptureWriter *writer,
+ int kallsyms_fd)
+{
+ SysprofLiveUnwinder *self;
+ g_autofree char *mounts = NULL;
+
+ g_return_val_if_fail (writer != NULL, NULL);
+
+ self = g_object_new (SYSPROF_TYPE_LIVE_UNWINDER, NULL);
+ self->writer = sysprof_capture_writer_ref (writer);
+
+ if (kallsyms_fd != -1)
+ {
+ sysprof_capture_writer_add_file_fd (writer,
+ SYSPROF_CAPTURE_CURRENT_TIME,
+ -1,
+ -1,
+ "/proc/kallsyms",
+ kallsyms_fd);
+ close (kallsyms_fd);
+ }
+
+ mounts = sysprof_live_unwinder_read_file (self, "/proc/mounts", TRUE);
+
+ sysprof_live_unwinder_mine_pids (self);
+
+ return self;
+}
+
+void
+sysprof_live_unwinder_seen_process (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ const char *comm)
+{
+ G_GNUC_UNUSED SysprofLiveProcess *live_pid;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+
+ live_pid = sysprof_live_unwinder_find_pid (self, pid, FALSE);
+
+ sysprof_capture_writer_add_process (self->writer, time, cpu, pid, comm);
+}
+
+void
+sysprof_live_unwinder_process_exited (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid)
+{
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+
+ sysprof_capture_writer_add_exit (self->writer, time, cpu, pid);
+}
+
+void
+sysprof_live_unwinder_process_forked (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid parent_tid,
+ GPid tid)
+{
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+
+ sysprof_capture_writer_add_fork (self->writer, time, cpu, parent_tid, tid);
+}
+
+void
+sysprof_live_unwinder_track_mmap (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ SysprofCaptureAddress begin,
+ SysprofCaptureAddress end,
+ SysprofCaptureAddress offset,
+ guint64 inode,
+ const char *filename,
+ const char *build_id)
+{
+ G_GNUC_UNUSED SysprofLiveProcess *live_pid;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+
+ live_pid = sysprof_live_unwinder_find_pid (self, pid, TRUE);
+
+ if (build_id != NULL)
+ sysprof_capture_writer_add_map_with_build_id (self->writer, time, cpu, pid,
+ begin, end, offset,
+ inode, filename,
+ build_id);
+ else
+ sysprof_capture_writer_add_map (self->writer, time, cpu, pid,
+ begin, end, offset,
+ inode, filename);
+
+ sysprof_live_process_add_map (live_pid, begin, end, offset, inode, filename);
+}
+
+void
+sysprof_live_unwinder_process_sampled (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ GPid tid,
+ const SysprofCaptureAddress *addresses,
+ guint n_addresses)
+{
+ G_GNUC_UNUSED SysprofLiveProcess *live_pid;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+
+ live_pid = sysprof_live_unwinder_find_pid (self, pid, TRUE);
+
+ sysprof_capture_writer_add_sample (self->writer, time, cpu, pid, tid,
+ addresses, n_addresses);
+}
+
+void
+sysprof_live_unwinder_process_sampled_with_stack (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ GPid tid,
+ const SysprofCaptureAddress *addresses,
+ guint n_addresses,
+ const guint8 *stack,
+ guint64 stack_size,
+ guint64 stack_dyn_size,
+ guint64 abi,
+ const guint64 *registers,
+ guint n_registers)
+{
+ SysprofLiveProcess *live_pid;
+ SysprofCaptureAddress unwound[256];
+ gboolean found_user = FALSE;
+ guint pos;
+
+ g_assert (SYSPROF_IS_LIVE_UNWINDER (self));
+ g_assert (stack != NULL);
+ g_assert (stack_dyn_size <= stack_size);
+
+ if (stack_dyn_size == 0 || n_addresses >= G_N_ELEMENTS (unwound))
+ {
+ sysprof_live_unwinder_process_sampled (self, time, cpu, pid, tid, addresses, n_addresses);
+ return;
+ }
+
+ live_pid = sysprof_live_unwinder_find_pid (self, pid, TRUE);
+
+ /* Copy addresses over (which might be kernel, context-switch, etc until
+ * we get to the PERF_CONTEXT_USER. We'll decode the stack right into the
+ * location after that.
+ */
+ for (pos = 0; pos < n_addresses; pos++)
+ {
+ unwound[pos] = addresses[pos];
+
+ if (addresses[pos] == PERF_CONTEXT_USER)
+ {
+ found_user = TRUE;
+ break;
+ }
+ }
+
+ /* If we didn't find a user context (but we have a stack size) synthesize
+ * the PERF_CONTEXT_USER now.
+ */
+ if (!found_user && pos < G_N_ELEMENTS (unwound))
+ unwound[pos++] = PERF_CONTEXT_USER;
+
+ /* Now request the live process unwind the user-space stack */
+ if (pos < G_N_ELEMENTS (unwound))
+ {
+ guint n_unwound;
+
+ n_unwound = sysprof_live_process_unwind (live_pid,
+ tid,
+ abi,
+ stack,
+ stack_dyn_size,
+ registers,
+ n_registers,
+ &unwound[pos],
+ G_N_ELEMENTS (unwound) - pos);
+
+ /* Only take DWARF unwind if it was better */
+ if (pos + n_unwound > n_addresses)
+ {
+ addresses = unwound;
+ n_addresses = pos + n_unwound;
+ }
+ }
+
+ sysprof_capture_writer_add_sample (self->writer, time, cpu, pid, tid, addresses, n_addresses);
+}
diff --git a/src/sysprof-live-unwinder/sysprof-live-unwinder.h b/src/sysprof-live-unwinder/sysprof-live-unwinder.h
new file mode 100644
index 00000000..e27ed9a4
--- /dev/null
+++ b/src/sysprof-live-unwinder/sysprof-live-unwinder.h
@@ -0,0 +1,79 @@
+/*
+ * sysprof-live-unwinder.h
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <sysprof.h>
+
+G_BEGIN_DECLS
+
+#define SYSPROF_TYPE_LIVE_UNWINDER (sysprof_live_unwinder_get_type())
+
+G_DECLARE_FINAL_TYPE (SysprofLiveUnwinder, sysprof_live_unwinder, SYSPROF, LIVE_UNWINDER, GObject)
+
+SysprofLiveUnwinder *sysprof_live_unwinder_new (SysprofCaptureWriter *writer,
+ int kallsyms_fd);
+void sysprof_live_unwinder_seen_process (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ const char *comm);
+void sysprof_live_unwinder_process_exited (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid);
+void sysprof_live_unwinder_process_forked (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid parent_tid,
+ GPid tid);
+void sysprof_live_unwinder_track_mmap (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ SysprofCaptureAddress begin,
+ SysprofCaptureAddress end,
+ SysprofCaptureAddress offset,
+ guint64 inode,
+ const char *filename,
+ const char *build_id);
+void sysprof_live_unwinder_process_sampled (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ GPid tid,
+ const SysprofCaptureAddress *addresses,
+ guint n_addresses);
+void sysprof_live_unwinder_process_sampled_with_stack (SysprofLiveUnwinder *self,
+ gint64 time,
+ int cpu,
+ GPid pid,
+ GPid tid,
+ const SysprofCaptureAddress *addresses,
+ guint n_addresses,
+ const guint8 *stack,
+ guint64 stack_size,
+ guint64 stack_dyn_size,
+ guint64 abi,
+ const guint64 *registers,
+ guint n_registers);
+
+G_END_DECLS
diff --git a/src/sysprof-live-unwinder/tests/meson.build b/src/sysprof-live-unwinder/tests/meson.build
new file mode 100644
index 00000000..9e1a945a
--- /dev/null
+++ b/src/sysprof-live-unwinder/tests/meson.build
@@ -0,0 +1,35 @@
+sysprof_live_unwinder_test_env = [
+ 'G_DEBUG=gc-friendly',
+ 'GSETTINGS_BACKEND=memory',
+ 'MALLOC_CHECK_=2',
+]
+
+sysprof_live_unwinder_testsuite_c_args = [
+ '-DG_ENABLE_DEBUG',
+ '-UG_DISABLE_ASSERT',
+ '-UG_DISABLE_CAST_CHECKS',
+ '-DBUILDDIR="@0@"'.format(meson.current_build_dir()),
+]
+
+sysprof_live_unwinder_testsuite = {
+ 'test-live-unwinder' : {'skip': true},
+}
+
+sysprof_live_unwinder_testsuite_deps = [
+ libsysprof_static_dep,
+]
+
+if polkit_agent_dep.found()
+ sysprof_live_unwinder_testsuite_deps += polkit_agent_dep
+endif
+
+foreach test, params: sysprof_live_unwinder_testsuite
+ test_exe = executable(test, '@0@.c'.format(test),
+ c_args: sysprof_live_unwinder_testsuite_c_args,
+ dependencies: sysprof_live_unwinder_testsuite_deps,
+ )
+
+ if not params.get('skip', false)
+ test(test, test_exe, env: sysprof_live_unwinder_test_env)
+ endif
+endforeach
diff --git a/src/sysprof-live-unwinder/tests/test-live-unwinder.c b/src/sysprof-live-unwinder/tests/test-live-unwinder.c
new file mode 100644
index 00000000..114cc568
--- /dev/null
+++ b/src/sysprof-live-unwinder/tests/test-live-unwinder.c
@@ -0,0 +1,391 @@
+/*
+ * test-live-unwinder.c
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <sys/ioctl.h>
+
+#include <glib/gstdio.h>
+#include <gio/gio.h>
+
+#include <libdex.h>
+
+#include <sysprof.h>
+
+#include "sysprof-perf-event-stream-private.h"
+
+#if HAVE_POLKIT_AGENT
+# define POLKIT_AGENT_I_KNOW_API_IS_SUBJECT_TO_CHANGE
+# include <polkit/polkit.h>
+# include <polkitagent/polkitagent.h>
+#endif
+
+#include <asm/perf_regs.h>
+
+#define N_WAKEUP_EVENTS 149
+
+/* The following was provided to Sysprof by Serhei Makarov as part
+ * of the eu-stacktrace prototype work.
+ */
+#ifdef _ASM_X86_PERF_REGS_H
+/* #define SYSPROF_ARCH_PREFERRED_REGS PERF_REG_EXTENDED_MASK -- error on x86_64 due to including segment regs*/
+#define REG(R) (1ULL << PERF_REG_X86_ ## R)
+#define DWARF_NEEDED_REGS (/* no FLAGS */ REG(IP) | REG(SP) | REG(AX) | REG(CX) | REG(DX) | REG(BX) | REG(SI) | REG(DI) | REG(SP) | REG(BP) | /* no segment regs */ REG(R8) | REG(R9) | REG(R10) | REG(R11) | REG(R12) | REG(R13) | REG(R14) | REG(R15))
+/* XXX register ordering is defined in linux arch/x86/include/uapi/asm/perf_regs.h;
+ see code in tools/perf/util/intel-pt.c intel_pt_add_gp_regs()
+ and note how registers are added in the same order as the perf_regs.h enum */
+#define SYSPROF_ARCH_PREFERRED_REGS DWARF_NEEDED_REGS
+/* TODO: add other architectures, imitating the linux tools/perf tree */
+#else
+# define SYSPROF_ARCH_PREFERRED_REGS PERF_REG_EXTENDED_MASK
+#endif /* _ASM_{arch}_PERF_REGS_H */
+
+static gboolean sample_stack;
+static char *kallsyms = NULL;
+static int sample_stack_size = 8192;
+
+static void
+open_perf_stream_cb (GObject *object,
+ GAsyncResult *result,
+ gpointer user_data)
+{
+ GDBusConnection *connection = (GDBusConnection *)object;
+ g_autoptr(DexPromise) promise = user_data;
+ g_autoptr(GUnixFDList) fd_list = NULL;
+ g_autoptr(GVariant) ret = NULL;
+ g_autoptr(GError) error = NULL;
+
+ g_assert (G_IS_DBUS_CONNECTION (connection));
+ g_assert (G_IS_ASYNC_RESULT (result));
+ g_assert (DEX_IS_PROMISE (promise));
+
+ if ((ret = g_dbus_connection_call_with_unix_fd_list_finish (connection, &fd_list, result, &error)))
+ {
+ int handle;
+ int fd;
+
+ g_variant_get (ret, "(h)", &handle);
+
+ if (-1 != (fd = g_unix_fd_list_get (fd_list, handle, &error)))
+ {
+ dex_promise_resolve_fd (promise, g_steal_fd (&fd));
+ return;
+ }
+ }
+
+ g_assert (error != NULL);
+
+ dex_promise_reject (promise, g_steal_pointer (&error));
+}
+
+static int
+open_perf_stream (GDBusConnection *bus,
+ int cpu,
+ GError **error)
+{
+ struct perf_event_attr attr = {0};
+ gboolean with_mmap2 = TRUE;
+ gboolean use_software = FALSE;
+
+ g_assert (G_IS_DBUS_CONNECTION (bus));
+ g_assert (cpu >= 0);
+ g_assert (error != NULL);
+
+try_again:
+ attr.sample_type = PERF_SAMPLE_IP
+ | PERF_SAMPLE_TID
+ | PERF_SAMPLE_IDENTIFIER
+ | PERF_SAMPLE_CALLCHAIN
+ | PERF_SAMPLE_TIME;
+
+ if (sample_stack)
+ {
+ attr.sample_type |= (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER);
+ attr.sample_stack_user = sample_stack_size;
+ attr.sample_regs_user = SYSPROF_ARCH_PREFERRED_REGS;
+ }
+
+ attr.wakeup_events = N_WAKEUP_EVENTS;
+ attr.disabled = TRUE;
+ attr.mmap = TRUE;
+ attr.mmap2 = with_mmap2;
+ attr.comm = 1;
+ attr.task = 1;
+ attr.exclude_idle = 1;
+ attr.sample_id_all = 1;
+
+#ifdef HAVE_PERF_CLOCKID
+ attr.clockid = sysprof_clock;
+ attr.use_clockid = 1;
+#endif
+
+ attr.size = sizeof attr;
+
+ if (use_software)
+ {
+ attr.type = PERF_TYPE_SOFTWARE;
+ attr.config = PERF_COUNT_SW_CPU_CLOCK;
+ attr.sample_period = 1000000;
+ }
+ else
+ {
+ attr.type = PERF_TYPE_HARDWARE;
+ attr.config = PERF_COUNT_HW_CPU_CYCLES;
+ attr.sample_period = 1200000;
+ }
+
+ {
+ g_autoptr(GVariant) options = _sysprof_perf_event_attr_to_variant (&attr);
+ g_autoptr(DexPromise) promise = dex_promise_new ();
+ g_autofd int fd = -1;
+
+ g_dbus_connection_call_with_unix_fd_list (bus,
+ "org.gnome.Sysprof3",
+ "/org/gnome/Sysprof3",
+ "org.gnome.Sysprof3.Service",
+ "PerfEventOpen",
+ g_variant_new ("(@a{sv}iiht)",
+ options,
+ -1,
+ cpu,
+ -1,
+ 0),
+ G_VARIANT_TYPE ("(h)"),
+ G_DBUS_CALL_FLAGS_ALLOW_INTERACTIVE_AUTHORIZATION,
+ G_MAXUINT,
+ NULL,
+ dex_promise_get_cancellable (promise),
+ open_perf_stream_cb,
+ dex_ref (promise));
+
+ fd = dex_await_fd (dex_ref (promise), error);
+
+ if (*error == NULL)
+ {
+ g_printerr ("CPU[%d]: opened perf_event stream as FD %d\n", cpu, fd);
+ return g_steal_fd (&fd);
+ }
+
+ fd = -1;
+ }
+
+ if (with_mmap2)
+ {
+ g_clear_error (error);
+ with_mmap2 = FALSE;
+ goto try_again;
+ }
+
+ if (use_software == FALSE)
+ {
+ g_clear_error (error);
+ with_mmap2 = TRUE;
+ use_software = TRUE;
+ goto try_again;
+ }
+
+ g_assert (*error != NULL);
+
+ return -1;
+}
+
+static DexFuture *
+main_fiber (gpointer user_data)
+{
+ g_autoptr(GSubprocessLauncher) launcher = NULL;
+ g_autoptr(GDBusConnection) bus = NULL;
+ g_autoptr(GSubprocess) subprocess = NULL;
+ g_autoptr(GPtrArray) argv = NULL;
+ g_autoptr(GError) error = NULL;
+ g_autofd int writer_fd = -1;
+ int n_cpu = g_get_num_processors ();
+ int next_target_fd = 3;
+
+ /* Get our bus we will use for authorization */
+ if (!(bus = dex_await_object (dex_bus_get (G_BUS_TYPE_SYSTEM), &error)))
+ return dex_future_new_for_error (g_steal_pointer (&error));
+
+ /* Setup our launcher we'll use to map FDs into the translator */
+ launcher = g_subprocess_launcher_new (0);
+
+ /* Setup our argv which will notify the child about where to
+ * find the FDs containing perf event streams.
+ */
+ argv = g_ptr_array_new_with_free_func (g_free);
+ g_ptr_array_add (argv, g_build_filename (BUILDDIR, "..", "sysprof-live-unwinder", NULL));
+
+ /* Provide kallsyms from the file provided */
+ if (kallsyms != NULL)
+ {
+ int fd = open (kallsyms, O_RDONLY | O_CLOEXEC);
+
+ if (fd != -1)
+ {
+ g_subprocess_launcher_take_fd (launcher, fd, next_target_fd);
+ g_ptr_array_add (argv, g_strdup_printf ("--kallsyms=%d", next_target_fd++));
+ }
+ }
+
+ if (sample_stack)
+ g_ptr_array_add (argv, g_strdup_printf ("--stack-size=%u", sample_stack_size));
+
+ g_printerr ("sysprof-live-unwinder at %s\n", (const char *)argv->pdata[0]);
+
+ /* First try to open a perf_event stream for as many CPUs as we
+ * can before we get complaints from the kernel.
+ */
+ for (int cpu = 0; cpu < n_cpu; cpu++)
+ {
+ g_autoptr(GError) cpu_error = NULL;
+ g_autofd int perf_fd = open_perf_stream (bus, cpu, &cpu_error);
+
+ if (perf_fd == -1)
+ {
+ g_printerr ("CPU[%d]: %s\n", cpu, cpu_error->message);
+ continue;
+ }
+
+ if (0 != ioctl (perf_fd, PERF_EVENT_IOC_ENABLE))
+ {
+ int errsv = errno;
+ g_warning ("Failed to enable perf_fd: %s", g_strerror (errsv));
+ }
+
+ g_ptr_array_add (argv, g_strdup_printf ("--perf-fd=%d:%d", next_target_fd, cpu));
+ g_subprocess_launcher_take_fd (launcher, g_steal_fd (&perf_fd), next_target_fd);
+
+ next_target_fd++;
+ }
+
+ /* Now create a FD for our destination capture. */
+ if (-1 == (writer_fd = open ("translated.syscap", O_CREAT|O_RDWR|O_CLOEXEC, 0664)) ||
+ ftruncate (writer_fd, 0) != 0)
+ return dex_future_new_for_errno (errno);
+ g_ptr_array_add (argv, g_strdup_printf ("--capture-fd=%d", next_target_fd));
+ g_subprocess_launcher_take_fd (launcher, g_steal_fd (&writer_fd), next_target_fd);
+ next_target_fd++;
+
+ /* Null-terminate our argv */
+ g_ptr_array_add (argv, NULL);
+
+ /* Spawn our worker process with the perf FDs and writer provided */
+ if (!(subprocess = g_subprocess_launcher_spawnv (launcher,
+ (const char * const *)argv->pdata,
+ &error)))
+ return dex_future_new_for_error (g_steal_pointer (&error));
+
+ /* Now wait for the translation process to complete */
+ if (!dex_await_boolean (dex_subprocess_wait_check (subprocess), &error))
+ return dex_future_new_for_error (g_steal_pointer (&error));
+
+ return dex_future_new_true ();
+}
+
+static DexFuture *
+finally_cb (DexFuture *future,
+ gpointer user_data)
+{
+ g_autoptr(GError) error = NULL;
+ GMainLoop *main_loop = user_data;
+
+ if (!dex_await (dex_ref (future), &error))
+ {
+ g_printerr ("Error: %s\n", error->message);
+ exit (EXIT_FAILURE);
+ }
+
+ g_main_loop_quit (main_loop);
+
+ return NULL;
+}
+
+int
+main (int argc,
+ char *argv[])
+{
+#if HAVE_POLKIT_AGENT
+ PolkitAgentListener *polkit = NULL;
+ PolkitSubject *subject = NULL;
+#endif
+ g_autoptr(GOptionContext) context = NULL;
+ g_autoptr(GMainLoop) main_loop = NULL;
+ g_autoptr(GError) error = NULL;
+ DexFuture *future;
+ GOptionEntry entries[] = {
+ { "sample-stack", 's', 0, G_OPTION_ARG_NONE, &sample_stack, "If the stack should be sampled for user-space unwinding" },
+ { "sample-stack-size", 'S', 0, G_OPTION_ARG_INT, &sample_stack_size, "If size of the stack to sample in bytes" },
+ { "kallsyms", 'k', 0, G_OPTION_ARG_FILENAME, &kallsyms, "Specify kallsyms for use" },
+ { NULL }
+ };
+
+ sysprof_clock_init ();
+ dex_init ();
+
+ main_loop = g_main_loop_new (NULL, FALSE);
+ context = g_option_context_new ("- test sysprof-live-unwinder");
+ g_option_context_add_main_entries (context, entries, NULL);
+
+ if (!g_option_context_parse (context, &argc, &argv, &error))
+ {
+ g_printerr ("%s\n", error->message);
+ return EXIT_FAILURE;
+ }
+
+#if HAVE_POLKIT_AGENT
+ /* Start polkit agent so that we can elevate privileges from a TTY */
+ if (g_getenv ("DESKTOP_SESSION") == NULL &&
+ (subject = polkit_unix_process_new_for_owner (getpid (), 0, -1)))
+ {
+ g_autoptr(GError) pkerror = NULL;
+
+ polkit = polkit_agent_text_listener_new (NULL, NULL);
+ polkit_agent_listener_register (polkit,
+ POLKIT_AGENT_REGISTER_FLAGS_NONE,
+ subject,
+ NULL,
+ NULL,
+ &pkerror);
+
+ if (pkerror != NULL)
+ {
+ g_dbus_error_strip_remote_error (pkerror);
+ g_printerr ("Failed to register polkit agent: %s\n",
+ pkerror->message);
+ }
+ }
+#endif
+
+ future = dex_scheduler_spawn (NULL, 0, main_fiber, NULL, NULL);
+ future = dex_future_finally (future,
+ finally_cb,
+ g_main_loop_ref (main_loop),
+ (GDestroyNotify) g_main_loop_unref);
+ dex_future_disown (future);
+
+ g_main_loop_run (main_loop);
+
+ g_clear_pointer (&kallsyms, g_free);
+
+ return EXIT_SUCCESS;
+}
diff --git a/src/sysprofd/ipc-unwinder-impl.c b/src/sysprofd/ipc-unwinder-impl.c
new file mode 100644
index 00000000..7f218de6
--- /dev/null
+++ b/src/sysprofd/ipc-unwinder-impl.c
@@ -0,0 +1,247 @@
+/*
+ * ipc-unwinder-impl.c
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#define G_LOG_DOMAIN "ipc-unwinder-impl"
+
+#include "config.h"
+
+#include <errno.h>
+
+#include <signal.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+
+#include <glib/gstdio.h>
+
+#include <polkit/polkit.h>
+
+#include "ipc-unwinder-impl.h"
+
+struct _IpcUnwinderImpl
+{
+ IpcUnwinderSkeleton parent_instance;
+};
+
+static void
+child_setup (gpointer data)
+{
+ prctl (PR_SET_PDEATHSIG, SIGKILL);
+}
+
+static gboolean
+ipc_unwinder_impl_handle_unwind (IpcUnwinder *unwinder,
+ GDBusMethodInvocation *invocation,
+ GUnixFDList *fd_list,
+ guint stack_size,
+ GVariant *arg_perf_fds,
+ GVariant *arg_event_fd)
+{
+ g_autoptr(GSubprocessLauncher) launcher = NULL;
+ g_autoptr(GSubprocess) subprocess = NULL;
+ g_autoptr(GUnixFDList) out_fd_list = NULL;
+ g_autoptr(GPtrArray) argv = NULL;
+ g_autoptr(GError) error = NULL;
+ g_autofd int our_fd = -1;
+ g_autofd int their_fd = -1;
+ g_autofd int event_fd = -1;
+ GVariantIter iter;
+ int capture_fd_handle;
+ int pair[2];
+ int next_target_fd = 3;
+ int perf_fd_handle;
+ int cpu;
+
+ g_assert (IPC_IS_UNWINDER_IMPL (unwinder));
+ g_assert (G_IS_DBUS_METHOD_INVOCATION (invocation));
+ g_assert (!fd_list || G_IS_UNIX_FD_LIST (fd_list));
+
+ if (stack_size == 0 || stack_size % sysconf (_SC_PAGESIZE) != 0)
+ {
+ g_dbus_method_invocation_return_error_literal (g_steal_pointer (&invocation),
+ G_DBUS_ERROR,
+ G_DBUS_ERROR_INVALID_ARGS,
+ "Stack size must be a multiple of the page size");
+ return TRUE;
+ }
+
+ if (fd_list == NULL)
+ {
+ g_dbus_method_invocation_return_error_literal (g_steal_pointer (&invocation),
+ G_DBUS_ERROR,
+ G_DBUS_ERROR_FILE_NOT_FOUND,
+ "Missing perf FDs");
+ return TRUE;
+ }
+
+ launcher = g_subprocess_launcher_new (0);
+ argv = g_ptr_array_new_with_free_func (g_free);
+
+ g_ptr_array_add (argv, g_strdup (PACKAGE_LIBEXECDIR "/sysprof-live-unwinder"));
+ g_ptr_array_add (argv, g_strdup_printf ("--stack-size=%u", stack_size));
+
+ if (-1 == (event_fd = g_unix_fd_list_get (fd_list, g_variant_get_handle (arg_event_fd), &error)))
+ {
+ g_dbus_method_invocation_return_gerror (g_steal_pointer (&invocation), error);
+ return TRUE;
+ }
+
+ g_ptr_array_add (argv, g_strdup_printf ("--event-fd=%u", next_target_fd));
+ g_subprocess_launcher_take_fd (launcher, g_steal_fd (&event_fd), next_target_fd++);
+
+ g_variant_iter_init (&iter, arg_perf_fds);
+
+ while (g_variant_iter_loop (&iter, "(hi)", &perf_fd_handle, &cpu))
+ {
+ g_autofd int perf_fd = g_unix_fd_list_get (fd_list, perf_fd_handle, &error);
+
+ if (perf_fd < 0)
+ {
+ g_dbus_method_invocation_return_gerror (g_steal_pointer (&invocation), error);
+ return TRUE;
+ }
+
+ g_ptr_array_add (argv, g_strdup_printf ("--perf-fd=%d:%d", next_target_fd, cpu));
+ g_subprocess_launcher_take_fd (launcher,
+ g_steal_fd (&perf_fd),
+ next_target_fd++);
+ }
+
+ g_subprocess_launcher_set_child_setup (launcher, child_setup, NULL, NULL);
+
+ if (socketpair (AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, pair) < 0)
+ {
+ int errsv = errno;
+ g_dbus_method_invocation_return_error_literal (g_steal_pointer (&invocation),
+ G_IO_ERROR,
+ g_io_error_from_errno (errsv),
+ g_strerror (errsv));
+ return TRUE;
+ }
+
+ our_fd = g_steal_fd (&pair[0]);
+ their_fd = g_steal_fd (&pair[1]);
+
+ out_fd_list = g_unix_fd_list_new ();
+ capture_fd_handle = g_unix_fd_list_append (out_fd_list, their_fd, &error);
+
+ if (capture_fd_handle < 0)
+ {
+ g_dbus_method_invocation_return_gerror (g_steal_pointer (&invocation), error);
+ return TRUE;
+ }
+
+ g_ptr_array_add (argv, g_strdup_printf ("--capture-fd=%d", next_target_fd));
+ g_subprocess_launcher_take_fd (launcher, g_steal_fd (&our_fd), next_target_fd++);
+
+ g_ptr_array_add (argv, NULL);
+
+ if (!(subprocess = g_subprocess_launcher_spawnv (launcher, (const char * const *)argv->pdata, &error)))
+ {
+ g_dbus_method_invocation_return_gerror (g_steal_pointer (&invocation), error);
+ return TRUE;
+ }
+
+ ipc_unwinder_complete_unwind (unwinder,
+ g_steal_pointer (&invocation),
+ out_fd_list,
+ g_variant_new_handle (capture_fd_handle));
+
+ g_subprocess_wait_async (subprocess, NULL, NULL, NULL);
+
+ return TRUE;
+}
+
+static void
+unwinder_iface_init (IpcUnwinderIface *iface)
+{
+ iface->handle_unwind = ipc_unwinder_impl_handle_unwind;
+}
+
+G_DEFINE_FINAL_TYPE_WITH_CODE (IpcUnwinderImpl, ipc_unwinder_impl, IPC_TYPE_UNWINDER_SKELETON,
+ G_IMPLEMENT_INTERFACE (IPC_TYPE_UNWINDER, unwinder_iface_init))
+
+static gboolean
+ipc_unwinder_impl_g_authorize_method (GDBusInterfaceSkeleton *skeleton,
+ GDBusMethodInvocation *invocation)
+{
+ PolkitAuthorizationResult *res = NULL;
+ PolkitAuthority *authority = NULL;
+ PolkitSubject *subject = NULL;
+ const gchar *peer_name;
+ gboolean ret = TRUE;
+
+ g_assert (IPC_IS_UNWINDER_IMPL (skeleton));
+ g_assert (G_IS_DBUS_METHOD_INVOCATION (invocation));
+
+ peer_name = g_dbus_method_invocation_get_sender (invocation);
+
+ if (!(authority = polkit_authority_get_sync (NULL, NULL)) ||
+ !(subject = polkit_system_bus_name_new (peer_name)) ||
+ !(res = polkit_authority_check_authorization_sync (authority,
+ POLKIT_SUBJECT (subject),
+ "org.gnome.sysprof3.profile",
+ NULL,
+ POLKIT_CHECK_AUTHORIZATION_FLAGS_ALLOW_USER_INTERACTION,
+ NULL,
+ NULL)) ||
+ !polkit_authorization_result_get_is_authorized (res))
+ {
+ g_dbus_method_invocation_return_error (g_steal_pointer (&invocation),
+ G_DBUS_ERROR,
+ G_DBUS_ERROR_ACCESS_DENIED,
+ "Not authorized to make request");
+ ret = FALSE;
+ }
+
+ g_clear_object (&authority);
+ g_clear_object (&subject);
+ g_clear_object (&res);
+
+ return ret;
+}
+
+static void
+ipc_unwinder_impl_finalize (GObject *object)
+{
+ G_OBJECT_CLASS (ipc_unwinder_impl_parent_class)->finalize (object);
+}
+
+static void
+ipc_unwinder_impl_class_init (IpcUnwinderImplClass *klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+ GDBusInterfaceSkeletonClass *skeleton_class = G_DBUS_INTERFACE_SKELETON_CLASS (klass);
+
+ object_class->finalize = ipc_unwinder_impl_finalize;
+
+ skeleton_class->g_authorize_method = ipc_unwinder_impl_g_authorize_method;
+}
+
+static void
+ipc_unwinder_impl_init (IpcUnwinderImpl *self)
+{
+}
+
+IpcUnwinder *
+ipc_unwinder_impl_new (void)
+{
+ return g_object_new (IPC_TYPE_UNWINDER_IMPL, NULL);
+}
diff --git a/src/sysprofd/ipc-unwinder-impl.h b/src/sysprofd/ipc-unwinder-impl.h
new file mode 100644
index 00000000..ebe7a2f0
--- /dev/null
+++ b/src/sysprofd/ipc-unwinder-impl.h
@@ -0,0 +1,34 @@
+/*
+ * ipc-unwinder-impl.h
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include "ipc-unwinder.h"
+
+G_BEGIN_DECLS
+
+#define IPC_TYPE_UNWINDER_IMPL (ipc_unwinder_impl_get_type())
+
+G_DECLARE_FINAL_TYPE (IpcUnwinderImpl, ipc_unwinder_impl, IPC, UNWINDER_IMPL, IpcUnwinderSkeleton)
+
+IpcUnwinder *ipc_unwinder_impl_new (void);
+
+G_END_DECLS
diff --git a/src/sysprofd/meson.build b/src/sysprofd/meson.build
index 34901f44..b7e87ebe 100644
--- a/src/sysprofd/meson.build
+++ b/src/sysprofd/meson.build
@@ -10,18 +10,24 @@ ipc_service_src = gnome.gdbus_codegen('ipc-service',
namespace: 'Ipc',
)
+ipc_unwinder_src = gnome.gdbus_codegen('ipc-unwinder',
+ sources: 'org.gnome.Sysprof3.Unwinder.xml',
+ interface_prefix: 'org.gnome.Sysprof3.',
+ namespace: 'Ipc',
+)
+
sysprofd_sources = [
'sysprofd.c',
'ipc-rapl-profiler.c',
'ipc-service-impl.c',
+ 'ipc-unwinder-impl.c',
'sysprof-turbostat.c',
'helpers.c',
ipc_profiler_src,
ipc_service_src,
+ ipc_unwinder_src,
]
-pkglibexecdir = join_paths(get_option('prefix'), get_option('libexecdir'))
-
sysprofd_deps = [
glib_dep,
gio_dep,
diff --git a/src/sysprofd/org.gnome.Sysprof3.Unwinder.xml b/src/sysprofd/org.gnome.Sysprof3.Unwinder.xml
new file mode 100644
index 00000000..fb2c7848
--- /dev/null
+++ b/src/sysprofd/org.gnome.Sysprof3.Unwinder.xml
@@ -0,0 +1,23 @@
+<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN"
+"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
+<node>
+ <interface name="org.gnome.Sysprof3.Unwinder">
+ <!--
+ Unwind:
+ @stack_size: the size of stacks that are sampled
+ @perf_fds: an array of (perf_fd, CPU number)
+ @event_fd: an event fd to write to for notifying unwinder should exit
+ @capture_fd: (out): a FD that will be written to containing samples
+
+ Unwinding will stop when capture_fd can no longer be written to
+ such as being closed by the consumer of this API.
+ -->
+ <method name="Unwind">
+ <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
+ <arg type="u" name="stack_size" direction="in"/>
+ <arg type="a(hi)" name="perf_fds" direction="in"/>
+ <arg type="h" name="event_fd" direction="in"/>
+ <arg type="h" name="capture_fd" direction="out"/>
+ </method>
+ </interface>
+</node>
diff --git a/src/sysprofd/sysprofd.c b/src/sysprofd/sysprofd.c
index e39d59c4..7a7101e8 100644
--- a/src/sysprofd/sysprofd.c
+++ b/src/sysprofd/sysprofd.c
@@ -30,9 +30,11 @@
#include "ipc-rapl-profiler.h"
#include "ipc-service-impl.h"
+#include "ipc-unwinder-impl.h"
#define V3_PATH "/org/gnome/Sysprof3"
#define RAPL_PATH "/org/gnome/Sysprof3/RAPL"
+#define UNWINDER_PATH "/org/gnome/Sysprof3/Unwinder"
#define NAME_ACQUIRE_DELAY_SECS 3
#define INACTIVITY_TIMEOUT_SECS 120
@@ -126,6 +128,7 @@ main (gint argc,
{
g_autoptr(IpcProfiler) rapl = ipc_rapl_profiler_new ();
g_autoptr(IpcService) v3_service = ipc_service_impl_new ();
+ g_autoptr(IpcUnwinder) unwinder = ipc_unwinder_impl_new ();
g_signal_connect (v3_service, "activity", G_CALLBACK (activity_cb), NULL);
g_signal_connect (rapl, "activity", G_CALLBACK (activity_cb), NULL);
@@ -133,7 +136,8 @@ main (gint argc,
activity_cb (NULL, NULL);
if (g_dbus_interface_skeleton_export (G_DBUS_INTERFACE_SKELETON (v3_service), bus, V3_PATH, &error) &&
- g_dbus_interface_skeleton_export (G_DBUS_INTERFACE_SKELETON (rapl), bus, RAPL_PATH, &error))
+ g_dbus_interface_skeleton_export (G_DBUS_INTERFACE_SKELETON (rapl), bus, RAPL_PATH, &error) &&
+ g_dbus_interface_skeleton_export (G_DBUS_INTERFACE_SKELETON (unwinder), bus, UNWINDER_PATH, &error))
{
for (guint i = 0; i < G_N_ELEMENTS (bus_names); i++)
{
--
2.45.2