crash-gcore-command/SOURCES/0003-gcore-fix-memory-alloc...

129 lines
3.8 KiB
Diff

From 4cb65a0d9168778d120920418b968d05da10989f Mon Sep 17 00:00:00 2001
From: HATAYAMA Daisuke <d.hatayama@fujitsu.com>
Date: Fri, 25 Feb 2022 04:59:48 -0500
Subject: [PATCH 3/3] gcore: fix memory allocation failure during processing
NT_AUXV note
For crash dumps generated using kernel-4.18.0-365.el8 or later on
CentOS stream 8, crash gcore command fails as follows:
crash> gcore -v 7 -f 128 10604
gcore: Opening file core.10604.test-dumpfilter ...
gcore: done.
gcore: Writing ELF header ...
gcore: done.
gcore: Retrieving and writing note information ...
gcore: zero-size memory allocation! (called from 7fd558ce1e05)
Failed.
This memory allocation failure occurs in fill_auxv_note() that creates
NT_AUXV note due to saved_auxv entries of size and offset tables are
somehow 0.
This is because during the merge of the upstream kernel commit
1c33bb0507508af24fd754dd7123bd8e997fab2f (x86/elf: Support a new ELF
aux vector AT_MINSIGSTKSZ), location of saved_auxv of struct mm_struct
has been moved as workaround in order to avoid kABI breakage.
Fix this by using RHEL-specific location for saved_auxv if there is
member rh_reserved_saved_auxv in struct mm_struct.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@fujitsu.com>
---
src/libgcore/gcore_coredump.c | 54 +++++++++++++++++++++++++++++------
1 file changed, 46 insertions(+), 8 deletions(-)
diff --git a/src/libgcore/gcore_coredump.c b/src/libgcore/gcore_coredump.c
index 6f57b21b62b6..c14cc116e951 100644
--- a/src/libgcore/gcore_coredump.c
+++ b/src/libgcore/gcore_coredump.c
@@ -18,6 +18,10 @@
static struct elf_note_info *elf_note_info_init(void);
+static void get_auxv_size_addr(struct task_context *tc,
+ size_t *size,
+ ulong *addr);
+
static void fill_prstatus_note(struct elf_note_info *info,
struct task_context *tc,
struct memelfnote *memnote);
@@ -923,18 +927,49 @@ compat_fill_prstatus_note(struct elf_note_info *info,
#endif /* GCORE_ARCH_COMPAT */
+static void get_auxv_size_addr(struct task_context *tc,
+ size_t *psize,
+ ulong *paddr)
+{
+ size_t size;
+ ulong addr;
+
+ if (MEMBER_EXISTS("mm_struct", "rh_reserved_saved_auxv")) {
+ ulong mm_rh;
+
+ size = MEMBER_SIZE("mm_struct_rh", "saved_auxv");
+ readmem(task_mm(tc->task, FALSE) + MEMBER_OFFSET("mm_struct", "mm_rh"),
+ KVADDR,
+ &mm_rh,
+ sizeof(mm_rh),
+ "mm_struct mm_rh",
+ gcore_verbose_error_handle());
+ addr = mm_rh + MEMBER_OFFSET("mm_struct_rh", "saved_auxv");
+ } else {
+ size = MEMBER_SIZE("mm_struct", "saved_auxv");
+ addr = task_mm(tc->task, FALSE) +
+ MEMBER_OFFSET("mm_struct", "saved_auxv");
+ }
+
+ *psize = size;
+ *paddr = addr;
+}
+
static void
fill_auxv_note(struct elf_note_info *info, struct task_context *tc,
struct memelfnote *memnote)
{
ulong *auxv;
+ ulong addr;
+ size_t size;
int i;
- auxv = (ulong *)GETBUF(MEMBER_SIZE("mm_struct", "saved_auxv"));
+ get_auxv_size_addr(tc, &size, &addr);
- readmem(task_mm(tc->task, FALSE) +
- MEMBER_OFFSET("mm_struct", "saved_auxv"), KVADDR, auxv,
- MEMBER_SIZE("mm_struct", "saved_auxv"), "fill_auxv_note",
+ auxv = (ulong *)GETBUF(size);
+
+ readmem(addr, KVADDR, auxv,
+ size, "fill_auxv_note",
gcore_verbose_error_handle());
i = 0;
@@ -954,13 +989,16 @@ compat_fill_auxv_note(struct elf_note_info *info,
struct memelfnote *memnote)
{
uint32_t *auxv;
+ ulong addr;
+ size_t size;
int i;
- auxv = (uint32_t *)GETBUF(MEMBER_SIZE("mm_struct", "saved_auxv"));
+ get_auxv_size_addr(tc, &size, &addr);
+
+ auxv = (uint32_t *)GETBUF(size);
- readmem(task_mm(tc->task, FALSE) +
- MEMBER_OFFSET("mm_struct", "saved_auxv"), KVADDR, auxv,
- MEMBER_SIZE("mm_struct", "saved_auxv"), "fill_auxv_note32",
+ readmem(addr, KVADDR, auxv,
+ size, "fill_auxv_note32",
gcore_verbose_error_handle());
i = 0;
--
2.30.2