Add uprobe backports from -tip from Anton Arapov
This commit is contained in:
parent
b718a988d5
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@ -62,7 +62,7 @@ Summary: The Linux kernel
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# For non-released -rc kernels, this will be appended after the rcX and
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# gitX tags, so a 3 here would become part of release "0.rcX.gitX.3"
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#
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%global baserelease 3
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%global baserelease 4
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%global fedora_build %{baserelease}
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# base_sublevel is the kernel version we're starting with and patching
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@ -713,6 +713,8 @@ Patch14000: hibernate-freeze-filesystems.patch
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Patch14010: lis3-improve-handling-of-null-rate.patch
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Patch20000: uprobes-3.5-tip.patch
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# ARM
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# OMAP
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Patch21000: arm-omap-3.5-fixes.patch
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@ -1413,6 +1415,8 @@ ApplyPatch efi-dont-map-boot-services-on-32bit.patch
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ApplyPatch lis3-improve-handling-of-null-rate.patch
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ApplyPatch uprobes-3.5-tip.patch
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ApplyPatch power-x86-destdir.patch
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ApplyPatch hfsplus-Fix-bless-ioctl-when-used-with-hardlinks.patch
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@ -2282,6 +2286,9 @@ fi
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# ||----w |
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# || ||
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%changelog
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* Fri Jun 22 2012 Josh Boyer <jwboyer@redhat.com>
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- Add uprobe backports from -tip from Anton Arapov
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* Wed Jun 20 2012 Josh Boyer <jwboyer@redhat.com>
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- Fix incorrect logic in irqpoll patch
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uprobes-3.5-tip.patch
Normal file
915
uprobes-3.5-tip.patch
Normal file
@ -0,0 +1,915 @@
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The split-out series is available in the git repository at:
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git://fedorapeople.org/home/fedora/aarapov/public_git/kernel-uprobes.git tags/rawhide_exported
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Ananth N Mavinakayanahalli (1):
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uprobes: Pass probed vaddr to arch_uprobe_analyze_insn()
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Josh Stone (1):
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uprobes: add exports necessary for uprobes use by modules
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Oleg Nesterov (21):
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uprobes: Optimize is_swbp_at_addr() for current->mm
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uprobes: Change read_opcode() to use FOLL_FORCE
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uprobes: Introduce find_active_uprobe() helper
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uprobes: Teach find_active_uprobe() to provide the "is_swbp" info
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uprobes: Change register_for_each_vma() to take mm->mmap_sem for writing
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uprobes: Teach handle_swbp() to rely on "is_swbp" rather than uprobes_srcu
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uprobes: Kill uprobes_srcu/uprobe_srcu_id
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uprobes: Valid_vma() should reject VM_HUGETLB
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uprobes: __copy_insn() should ensure a_ops->readpage != NULL
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uprobes: Write_opcode()->__replace_page() can race with try_to_unmap()
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uprobes: Install_breakpoint() should fail if is_swbp_insn() == T
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uprobes: Rework register_for_each_vma() to make it O(n)
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uprobes: Change build_map_info() to try kmalloc(GFP_NOWAIT) first
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uprobes: Copy_insn() shouldn't depend on mm/vma/vaddr
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uprobes: Copy_insn() should not return -ENOMEM if __copy_insn() fails
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uprobes: No need to re-check vma_address() in write_opcode()
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uprobes: Simplify the usage of uprobe->pending_list
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uprobes: Don't use loff_t for the valid virtual address
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uprobes: __copy_insn() needs "loff_t offset"
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uprobes: Remove the unnecessary initialization in add_utask()
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uprobes: Move BUG_ON(UPROBE_SWBP_INSN_SIZE) from write_opcode() to install_breakpoint()
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Peter Zijlstra (1):
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uprobes: Document uprobe_register() vs uprobe_mmap() race
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Signed-off-by: Anton Arapov <anton@redhat.com>
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---
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arch/x86/include/asm/uprobes.h | 2 +-
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arch/x86/kernel/ptrace.c | 6 +
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arch/x86/kernel/uprobes.c | 3 +-
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include/linux/sched.h | 1 -
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kernel/events/uprobes.c | 464 ++++++++++++++++++++--------------------
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5 files changed, 240 insertions(+), 236 deletions(-)
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diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h
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index 1e9bed1..f3971bb 100644
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--- a/arch/x86/include/asm/uprobes.h
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+++ b/arch/x86/include/asm/uprobes.h
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@@ -48,7 +48,7 @@ struct arch_uprobe_task {
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#endif
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};
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-extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm);
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+extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr);
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extern int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs);
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extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
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extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
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diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
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index c4c6a5c..a6a6871 100644
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--- a/arch/x86/kernel/ptrace.c
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+++ b/arch/x86/kernel/ptrace.c
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@@ -1415,6 +1415,12 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
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#endif
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}
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+/*
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+ * This is declared in linux/regset.h and defined in machine-dependent
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+ * code. We put the export here to ensure no machine forgets it.
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+ */
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+EXPORT_SYMBOL_GPL(task_user_regset_view);
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+
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static void fill_sigtrap_info(struct task_struct *tsk,
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struct pt_regs *regs,
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int error_code, int si_code,
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diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
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index dc4e910..36fd420 100644
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--- a/arch/x86/kernel/uprobes.c
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+++ b/arch/x86/kernel/uprobes.c
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@@ -409,9 +409,10 @@ static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm,
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* arch_uprobe_analyze_insn - instruction analysis including validity and fixups.
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* @mm: the probed address space.
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* @arch_uprobe: the probepoint information.
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+ * @addr: virtual address at which to install the probepoint
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* Return 0 on success or a -ve number on error.
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*/
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-int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm)
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+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long addr)
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{
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int ret;
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struct insn insn;
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diff --git a/include/linux/sched.h b/include/linux/sched.h
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index 4059c0f..c7cfa69 100644
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--- a/include/linux/sched.h
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+++ b/include/linux/sched.h
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@@ -1581,7 +1581,6 @@ struct task_struct {
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#endif
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#ifdef CONFIG_UPROBES
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struct uprobe_task *utask;
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- int uprobe_srcu_id;
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#endif
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};
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diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
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index 985be4d..d9e5ba5 100644
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--- a/kernel/events/uprobes.c
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+++ b/kernel/events/uprobes.c
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@@ -34,17 +34,34 @@
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#include <linux/kdebug.h> /* notifier mechanism */
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#include <linux/uprobes.h>
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+#include <linux/export.h>
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#define UINSNS_PER_PAGE (PAGE_SIZE/UPROBE_XOL_SLOT_BYTES)
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#define MAX_UPROBE_XOL_SLOTS UINSNS_PER_PAGE
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-static struct srcu_struct uprobes_srcu;
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static struct rb_root uprobes_tree = RB_ROOT;
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static DEFINE_SPINLOCK(uprobes_treelock); /* serialize rbtree access */
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#define UPROBES_HASH_SZ 13
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+/*
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+ * We need separate register/unregister and mmap/munmap lock hashes because
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+ * of mmap_sem nesting.
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+ *
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+ * uprobe_register() needs to install probes on (potentially) all processes
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+ * and thus needs to acquire multiple mmap_sems (consequtively, not
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+ * concurrently), whereas uprobe_mmap() is called while holding mmap_sem
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+ * for the particular process doing the mmap.
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+ *
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+ * uprobe_register()->register_for_each_vma() needs to drop/acquire mmap_sem
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+ * because of lock order against i_mmap_mutex. This means there's a hole in
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+ * the register vma iteration where a mmap() can happen.
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+ *
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+ * Thus uprobe_register() can race with uprobe_mmap() and we can try and
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+ * install a probe where one is already installed.
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+ */
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+
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/* serialize (un)register */
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static struct mutex uprobes_mutex[UPROBES_HASH_SZ];
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@@ -61,17 +78,6 @@ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ];
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*/
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static atomic_t uprobe_events = ATOMIC_INIT(0);
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-/*
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- * Maintain a temporary per vma info that can be used to search if a vma
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- * has already been handled. This structure is introduced since extending
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- * vm_area_struct wasnt recommended.
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- */
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-struct vma_info {
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- struct list_head probe_list;
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- struct mm_struct *mm;
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- loff_t vaddr;
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-};
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-
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struct uprobe {
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struct rb_node rb_node; /* node in the rb tree */
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atomic_t ref;
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@@ -100,7 +106,8 @@ static bool valid_vma(struct vm_area_struct *vma, bool is_register)
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if (!is_register)
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return true;
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- if ((vma->vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)) == (VM_READ|VM_EXEC))
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+ if ((vma->vm_flags & (VM_HUGETLB|VM_READ|VM_WRITE|VM_EXEC|VM_SHARED))
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+ == (VM_READ|VM_EXEC))
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return true;
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return false;
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@@ -129,33 +136,17 @@ static loff_t vma_address(struct vm_area_struct *vma, loff_t offset)
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static int __replace_page(struct vm_area_struct *vma, struct page *page, struct page *kpage)
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{
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struct mm_struct *mm = vma->vm_mm;
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- pgd_t *pgd;
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- pud_t *pud;
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- pmd_t *pmd;
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- pte_t *ptep;
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- spinlock_t *ptl;
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unsigned long addr;
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- int err = -EFAULT;
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+ spinlock_t *ptl;
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+ pte_t *ptep;
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addr = page_address_in_vma(page, vma);
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if (addr == -EFAULT)
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- goto out;
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-
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- pgd = pgd_offset(mm, addr);
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- if (!pgd_present(*pgd))
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- goto out;
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-
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- pud = pud_offset(pgd, addr);
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- if (!pud_present(*pud))
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- goto out;
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-
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- pmd = pmd_offset(pud, addr);
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- if (!pmd_present(*pmd))
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- goto out;
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+ return -EFAULT;
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- ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
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+ ptep = page_check_address(page, mm, addr, &ptl, 0);
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if (!ptep)
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- goto out;
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+ return -EAGAIN;
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get_page(kpage);
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page_add_new_anon_rmap(kpage, vma, addr);
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@@ -174,10 +165,8 @@ static int __replace_page(struct vm_area_struct *vma, struct page *page, struct
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try_to_free_swap(page);
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put_page(page);
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pte_unmap_unlock(ptep, ptl);
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- err = 0;
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-out:
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- return err;
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+ return 0;
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}
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/**
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@@ -222,9 +211,8 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
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void *vaddr_old, *vaddr_new;
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struct vm_area_struct *vma;
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struct uprobe *uprobe;
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- loff_t addr;
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int ret;
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-
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+retry:
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/* Read the page with vaddr into memory */
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ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma);
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if (ret <= 0)
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@@ -246,10 +234,6 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
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if (mapping != vma->vm_file->f_mapping)
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goto put_out;
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- addr = vma_address(vma, uprobe->offset);
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- if (vaddr != (unsigned long)addr)
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- goto put_out;
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-
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ret = -ENOMEM;
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new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
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if (!new_page)
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@@ -267,11 +251,7 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
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vaddr_new = kmap_atomic(new_page);
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memcpy(vaddr_new, vaddr_old, PAGE_SIZE);
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-
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- /* poke the new insn in, ASSUMES we don't cross page boundary */
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- vaddr &= ~PAGE_MASK;
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- BUG_ON(vaddr + UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
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- memcpy(vaddr_new + vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
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+ memcpy(vaddr_new + (vaddr & ~PAGE_MASK), &opcode, UPROBE_SWBP_INSN_SIZE);
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kunmap_atomic(vaddr_new);
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kunmap_atomic(vaddr_old);
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@@ -291,6 +271,8 @@ unlock_out:
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put_out:
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put_page(old_page);
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+ if (unlikely(ret == -EAGAIN))
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+ goto retry;
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return ret;
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}
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@@ -312,7 +294,7 @@ static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_
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void *vaddr_new;
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int ret;
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- ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &page, NULL);
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+ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
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if (ret <= 0)
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return ret;
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@@ -333,10 +315,20 @@ static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
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uprobe_opcode_t opcode;
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int result;
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+ if (current->mm == mm) {
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+ pagefault_disable();
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+ result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr,
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+ sizeof(opcode));
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+ pagefault_enable();
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+
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+ if (likely(result == 0))
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+ goto out;
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+ }
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+
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result = read_opcode(mm, vaddr, &opcode);
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if (result)
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return result;
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-
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+out:
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if (is_swbp_insn(&opcode))
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return 1;
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@@ -355,7 +347,9 @@ static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
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int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
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{
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int result;
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-
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+ /*
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+ * See the comment near uprobes_hash().
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+ */
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result = is_swbp_at_addr(mm, vaddr);
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if (result == 1)
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return -EEXIST;
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@@ -520,7 +514,6 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
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uprobe->inode = igrab(inode);
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uprobe->offset = offset;
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init_rwsem(&uprobe->consumer_rwsem);
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- INIT_LIST_HEAD(&uprobe->pending_list);
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/* add to uprobes_tree, sorted on inode:offset */
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cur_uprobe = insert_uprobe(uprobe);
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@@ -588,20 +581,22 @@ static bool consumer_del(struct uprobe *uprobe, struct uprobe_consumer *uc)
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}
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static int
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-__copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *insn,
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- unsigned long nbytes, unsigned long offset)
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+__copy_insn(struct address_space *mapping, struct file *filp, char *insn,
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+ unsigned long nbytes, loff_t offset)
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{
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- struct file *filp = vma->vm_file;
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struct page *page;
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void *vaddr;
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- unsigned long off1;
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- unsigned long idx;
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+ unsigned long off;
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+ pgoff_t idx;
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if (!filp)
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return -EINVAL;
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- idx = (unsigned long)(offset >> PAGE_CACHE_SHIFT);
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- off1 = offset &= ~PAGE_MASK;
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+ if (!mapping->a_ops->readpage)
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+ return -EIO;
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+
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+ idx = offset >> PAGE_CACHE_SHIFT;
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+ off = offset & ~PAGE_MASK;
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/*
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* Ensure that the page that has the original instruction is
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@@ -612,22 +607,20 @@ __copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *ins
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return PTR_ERR(page);
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vaddr = kmap_atomic(page);
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- memcpy(insn, vaddr + off1, nbytes);
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+ memcpy(insn, vaddr + off, nbytes);
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kunmap_atomic(vaddr);
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page_cache_release(page);
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return 0;
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}
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-static int
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-copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr)
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+static int copy_insn(struct uprobe *uprobe, struct file *filp)
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{
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struct address_space *mapping;
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unsigned long nbytes;
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int bytes;
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- addr &= ~PAGE_MASK;
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- nbytes = PAGE_SIZE - addr;
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+ nbytes = PAGE_SIZE - (uprobe->offset & ~PAGE_MASK);
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mapping = uprobe->inode->i_mapping;
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/* Instruction at end of binary; copy only available bytes */
|
||||
@@ -638,13 +631,13 @@ copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr)
|
||||
|
||||
/* Instruction at the page-boundary; copy bytes in second page */
|
||||
if (nbytes < bytes) {
|
||||
- if (__copy_insn(mapping, vma, uprobe->arch.insn + nbytes,
|
||||
- bytes - nbytes, uprobe->offset + nbytes))
|
||||
- return -ENOMEM;
|
||||
-
|
||||
+ int err = __copy_insn(mapping, filp, uprobe->arch.insn + nbytes,
|
||||
+ bytes - nbytes, uprobe->offset + nbytes);
|
||||
+ if (err)
|
||||
+ return err;
|
||||
bytes = nbytes;
|
||||
}
|
||||
- return __copy_insn(mapping, vma, uprobe->arch.insn, bytes, uprobe->offset);
|
||||
+ return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset);
|
||||
}
|
||||
|
||||
/*
|
||||
@@ -672,9 +665,8 @@ copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr)
|
||||
*/
|
||||
static int
|
||||
install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
|
||||
- struct vm_area_struct *vma, loff_t vaddr)
|
||||
+ struct vm_area_struct *vma, unsigned long vaddr)
|
||||
{
|
||||
- unsigned long addr;
|
||||
int ret;
|
||||
|
||||
/*
|
||||
@@ -687,20 +679,22 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
|
||||
if (!uprobe->consumers)
|
||||
return -EEXIST;
|
||||
|
||||
- addr = (unsigned long)vaddr;
|
||||
-
|
||||
if (!(uprobe->flags & UPROBE_COPY_INSN)) {
|
||||
- ret = copy_insn(uprobe, vma, addr);
|
||||
+ ret = copy_insn(uprobe, vma->vm_file);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
|
||||
- return -EEXIST;
|
||||
+ return -ENOTSUPP;
|
||||
|
||||
- ret = arch_uprobe_analyze_insn(&uprobe->arch, mm);
|
||||
+ ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
+ /* write_opcode() assumes we don't cross page boundary */
|
||||
+ BUG_ON((uprobe->offset & ~PAGE_MASK) +
|
||||
+ UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
|
||||
+
|
||||
uprobe->flags |= UPROBE_COPY_INSN;
|
||||
}
|
||||
|
||||
@@ -713,7 +707,7 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
|
||||
* Hence increment before and decrement on failure.
|
||||
*/
|
||||
atomic_inc(&mm->uprobes_state.count);
|
||||
- ret = set_swbp(&uprobe->arch, mm, addr);
|
||||
+ ret = set_swbp(&uprobe->arch, mm, vaddr);
|
||||
if (ret)
|
||||
atomic_dec(&mm->uprobes_state.count);
|
||||
|
||||
@@ -721,27 +715,21 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
|
||||
}
|
||||
|
||||
static void
|
||||
-remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, loff_t vaddr)
|
||||
+remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)
|
||||
{
|
||||
- if (!set_orig_insn(&uprobe->arch, mm, (unsigned long)vaddr, true))
|
||||
+ if (!set_orig_insn(&uprobe->arch, mm, vaddr, true))
|
||||
atomic_dec(&mm->uprobes_state.count);
|
||||
}
|
||||
|
||||
/*
|
||||
- * There could be threads that have hit the breakpoint and are entering the
|
||||
- * notifier code and trying to acquire the uprobes_treelock. The thread
|
||||
- * calling delete_uprobe() that is removing the uprobe from the rb_tree can
|
||||
- * race with these threads and might acquire the uprobes_treelock compared
|
||||
- * to some of the breakpoint hit threads. In such a case, the breakpoint
|
||||
- * hit threads will not find the uprobe. The current unregistering thread
|
||||
- * waits till all other threads have hit a breakpoint, to acquire the
|
||||
- * uprobes_treelock before the uprobe is removed from the rbtree.
|
||||
+ * There could be threads that have already hit the breakpoint. They
|
||||
+ * will recheck the current insn and restart if find_uprobe() fails.
|
||||
+ * See find_active_uprobe().
|
||||
*/
|
||||
static void delete_uprobe(struct uprobe *uprobe)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
- synchronize_srcu(&uprobes_srcu);
|
||||
spin_lock_irqsave(&uprobes_treelock, flags);
|
||||
rb_erase(&uprobe->rb_node, &uprobes_tree);
|
||||
spin_unlock_irqrestore(&uprobes_treelock, flags);
|
||||
@@ -750,139 +738,135 @@ static void delete_uprobe(struct uprobe *uprobe)
|
||||
atomic_dec(&uprobe_events);
|
||||
}
|
||||
|
||||
-static struct vma_info *
|
||||
-__find_next_vma_info(struct address_space *mapping, struct list_head *head,
|
||||
- struct vma_info *vi, loff_t offset, bool is_register)
|
||||
+struct map_info {
|
||||
+ struct map_info *next;
|
||||
+ struct mm_struct *mm;
|
||||
+ unsigned long vaddr;
|
||||
+};
|
||||
+
|
||||
+static inline struct map_info *free_map_info(struct map_info *info)
|
||||
+{
|
||||
+ struct map_info *next = info->next;
|
||||
+ kfree(info);
|
||||
+ return next;
|
||||
+}
|
||||
+
|
||||
+static struct map_info *
|
||||
+build_map_info(struct address_space *mapping, loff_t offset, bool is_register)
|
||||
{
|
||||
+ unsigned long pgoff = offset >> PAGE_SHIFT;
|
||||
struct prio_tree_iter iter;
|
||||
struct vm_area_struct *vma;
|
||||
- struct vma_info *tmpvi;
|
||||
- unsigned long pgoff;
|
||||
- int existing_vma;
|
||||
- loff_t vaddr;
|
||||
-
|
||||
- pgoff = offset >> PAGE_SHIFT;
|
||||
+ struct map_info *curr = NULL;
|
||||
+ struct map_info *prev = NULL;
|
||||
+ struct map_info *info;
|
||||
+ int more = 0;
|
||||
|
||||
+ again:
|
||||
+ mutex_lock(&mapping->i_mmap_mutex);
|
||||
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
|
||||
if (!valid_vma(vma, is_register))
|
||||
continue;
|
||||
|
||||
- existing_vma = 0;
|
||||
- vaddr = vma_address(vma, offset);
|
||||
-
|
||||
- list_for_each_entry(tmpvi, head, probe_list) {
|
||||
- if (tmpvi->mm == vma->vm_mm && tmpvi->vaddr == vaddr) {
|
||||
- existing_vma = 1;
|
||||
- break;
|
||||
- }
|
||||
+ if (!prev && !more) {
|
||||
+ /*
|
||||
+ * Needs GFP_NOWAIT to avoid i_mmap_mutex recursion through
|
||||
+ * reclaim. This is optimistic, no harm done if it fails.
|
||||
+ */
|
||||
+ prev = kmalloc(sizeof(struct map_info),
|
||||
+ GFP_NOWAIT | __GFP_NOMEMALLOC | __GFP_NOWARN);
|
||||
+ if (prev)
|
||||
+ prev->next = NULL;
|
||||
}
|
||||
-
|
||||
- /*
|
||||
- * Another vma needs a probe to be installed. However skip
|
||||
- * installing the probe if the vma is about to be unlinked.
|
||||
- */
|
||||
- if (!existing_vma && atomic_inc_not_zero(&vma->vm_mm->mm_users)) {
|
||||
- vi->mm = vma->vm_mm;
|
||||
- vi->vaddr = vaddr;
|
||||
- list_add(&vi->probe_list, head);
|
||||
-
|
||||
- return vi;
|
||||
+ if (!prev) {
|
||||
+ more++;
|
||||
+ continue;
|
||||
}
|
||||
- }
|
||||
|
||||
- return NULL;
|
||||
-}
|
||||
-
|
||||
-/*
|
||||
- * Iterate in the rmap prio tree and find a vma where a probe has not
|
||||
- * yet been inserted.
|
||||
- */
|
||||
-static struct vma_info *
|
||||
-find_next_vma_info(struct address_space *mapping, struct list_head *head,
|
||||
- loff_t offset, bool is_register)
|
||||
-{
|
||||
- struct vma_info *vi, *retvi;
|
||||
+ if (!atomic_inc_not_zero(&vma->vm_mm->mm_users))
|
||||
+ continue;
|
||||
|
||||
- vi = kzalloc(sizeof(struct vma_info), GFP_KERNEL);
|
||||
- if (!vi)
|
||||
- return ERR_PTR(-ENOMEM);
|
||||
+ info = prev;
|
||||
+ prev = prev->next;
|
||||
+ info->next = curr;
|
||||
+ curr = info;
|
||||
|
||||
- mutex_lock(&mapping->i_mmap_mutex);
|
||||
- retvi = __find_next_vma_info(mapping, head, vi, offset, is_register);
|
||||
+ info->mm = vma->vm_mm;
|
||||
+ info->vaddr = vma_address(vma, offset);
|
||||
+ }
|
||||
mutex_unlock(&mapping->i_mmap_mutex);
|
||||
|
||||
- if (!retvi)
|
||||
- kfree(vi);
|
||||
+ if (!more)
|
||||
+ goto out;
|
||||
+
|
||||
+ prev = curr;
|
||||
+ while (curr) {
|
||||
+ mmput(curr->mm);
|
||||
+ curr = curr->next;
|
||||
+ }
|
||||
|
||||
- return retvi;
|
||||
+ do {
|
||||
+ info = kmalloc(sizeof(struct map_info), GFP_KERNEL);
|
||||
+ if (!info) {
|
||||
+ curr = ERR_PTR(-ENOMEM);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ info->next = prev;
|
||||
+ prev = info;
|
||||
+ } while (--more);
|
||||
+
|
||||
+ goto again;
|
||||
+ out:
|
||||
+ while (prev)
|
||||
+ prev = free_map_info(prev);
|
||||
+ return curr;
|
||||
}
|
||||
|
||||
static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
|
||||
{
|
||||
- struct list_head try_list;
|
||||
- struct vm_area_struct *vma;
|
||||
- struct address_space *mapping;
|
||||
- struct vma_info *vi, *tmpvi;
|
||||
- struct mm_struct *mm;
|
||||
- loff_t vaddr;
|
||||
- int ret;
|
||||
+ struct map_info *info;
|
||||
+ int err = 0;
|
||||
|
||||
- mapping = uprobe->inode->i_mapping;
|
||||
- INIT_LIST_HEAD(&try_list);
|
||||
+ info = build_map_info(uprobe->inode->i_mapping,
|
||||
+ uprobe->offset, is_register);
|
||||
+ if (IS_ERR(info))
|
||||
+ return PTR_ERR(info);
|
||||
|
||||
- ret = 0;
|
||||
+ while (info) {
|
||||
+ struct mm_struct *mm = info->mm;
|
||||
+ struct vm_area_struct *vma;
|
||||
|
||||
- for (;;) {
|
||||
- vi = find_next_vma_info(mapping, &try_list, uprobe->offset, is_register);
|
||||
- if (!vi)
|
||||
- break;
|
||||
+ if (err)
|
||||
+ goto free;
|
||||
|
||||
- if (IS_ERR(vi)) {
|
||||
- ret = PTR_ERR(vi);
|
||||
- break;
|
||||
- }
|
||||
+ down_write(&mm->mmap_sem);
|
||||
+ vma = find_vma(mm, (unsigned long)info->vaddr);
|
||||
+ if (!vma || !valid_vma(vma, is_register))
|
||||
+ goto unlock;
|
||||
|
||||
- mm = vi->mm;
|
||||
- down_read(&mm->mmap_sem);
|
||||
- vma = find_vma(mm, (unsigned long)vi->vaddr);
|
||||
- if (!vma || !valid_vma(vma, is_register)) {
|
||||
- list_del(&vi->probe_list);
|
||||
- kfree(vi);
|
||||
- up_read(&mm->mmap_sem);
|
||||
- mmput(mm);
|
||||
- continue;
|
||||
- }
|
||||
- vaddr = vma_address(vma, uprobe->offset);
|
||||
if (vma->vm_file->f_mapping->host != uprobe->inode ||
|
||||
- vaddr != vi->vaddr) {
|
||||
- list_del(&vi->probe_list);
|
||||
- kfree(vi);
|
||||
- up_read(&mm->mmap_sem);
|
||||
- mmput(mm);
|
||||
- continue;
|
||||
- }
|
||||
-
|
||||
- if (is_register)
|
||||
- ret = install_breakpoint(uprobe, mm, vma, vi->vaddr);
|
||||
- else
|
||||
- remove_breakpoint(uprobe, mm, vi->vaddr);
|
||||
+ vma_address(vma, uprobe->offset) != info->vaddr)
|
||||
+ goto unlock;
|
||||
|
||||
- up_read(&mm->mmap_sem);
|
||||
- mmput(mm);
|
||||
if (is_register) {
|
||||
- if (ret && ret == -EEXIST)
|
||||
- ret = 0;
|
||||
- if (ret)
|
||||
- break;
|
||||
+ err = install_breakpoint(uprobe, mm, vma, info->vaddr);
|
||||
+ /*
|
||||
+ * We can race against uprobe_mmap(), see the
|
||||
+ * comment near uprobe_hash().
|
||||
+ */
|
||||
+ if (err == -EEXIST)
|
||||
+ err = 0;
|
||||
+ } else {
|
||||
+ remove_breakpoint(uprobe, mm, info->vaddr);
|
||||
}
|
||||
+ unlock:
|
||||
+ up_write(&mm->mmap_sem);
|
||||
+ free:
|
||||
+ mmput(mm);
|
||||
+ info = free_map_info(info);
|
||||
}
|
||||
|
||||
- list_for_each_entry_safe(vi, tmpvi, &try_list, probe_list) {
|
||||
- list_del(&vi->probe_list);
|
||||
- kfree(vi);
|
||||
- }
|
||||
-
|
||||
- return ret;
|
||||
+ return err;
|
||||
}
|
||||
|
||||
static int __uprobe_register(struct uprobe *uprobe)
|
||||
@@ -945,6 +929,7 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
|
||||
|
||||
return ret;
|
||||
}
|
||||
+EXPORT_SYMBOL_GPL(uprobe_register);
|
||||
|
||||
/*
|
||||
* uprobe_unregister - unregister a already registered probe.
|
||||
@@ -976,6 +961,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
|
||||
if (uprobe)
|
||||
put_uprobe(uprobe);
|
||||
}
|
||||
+EXPORT_SYMBOL_GPL(uprobe_unregister);
|
||||
|
||||
/*
|
||||
* Of all the nodes that correspond to the given inode, return the node
|
||||
@@ -1048,7 +1034,7 @@ static void build_probe_list(struct inode *inode, struct list_head *head)
|
||||
int uprobe_mmap(struct vm_area_struct *vma)
|
||||
{
|
||||
struct list_head tmp_list;
|
||||
- struct uprobe *uprobe, *u;
|
||||
+ struct uprobe *uprobe;
|
||||
struct inode *inode;
|
||||
int ret, count;
|
||||
|
||||
@@ -1066,12 +1052,9 @@ int uprobe_mmap(struct vm_area_struct *vma)
|
||||
ret = 0;
|
||||
count = 0;
|
||||
|
||||
- list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
|
||||
- loff_t vaddr;
|
||||
-
|
||||
- list_del(&uprobe->pending_list);
|
||||
+ list_for_each_entry(uprobe, &tmp_list, pending_list) {
|
||||
if (!ret) {
|
||||
- vaddr = vma_address(vma, uprobe->offset);
|
||||
+ loff_t vaddr = vma_address(vma, uprobe->offset);
|
||||
|
||||
if (vaddr < vma->vm_start || vaddr >= vma->vm_end) {
|
||||
put_uprobe(uprobe);
|
||||
@@ -1079,8 +1062,10 @@ int uprobe_mmap(struct vm_area_struct *vma)
|
||||
}
|
||||
|
||||
ret = install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
|
||||
-
|
||||
- /* Ignore double add: */
|
||||
+ /*
|
||||
+ * We can race against uprobe_register(), see the
|
||||
+ * comment near uprobe_hash().
|
||||
+ */
|
||||
if (ret == -EEXIST) {
|
||||
ret = 0;
|
||||
|
||||
@@ -1115,7 +1100,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
|
||||
void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
|
||||
{
|
||||
struct list_head tmp_list;
|
||||
- struct uprobe *uprobe, *u;
|
||||
+ struct uprobe *uprobe;
|
||||
struct inode *inode;
|
||||
|
||||
if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
|
||||
@@ -1132,11 +1117,8 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon
|
||||
mutex_lock(uprobes_mmap_hash(inode));
|
||||
build_probe_list(inode, &tmp_list);
|
||||
|
||||
- list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
|
||||
- loff_t vaddr;
|
||||
-
|
||||
- list_del(&uprobe->pending_list);
|
||||
- vaddr = vma_address(vma, uprobe->offset);
|
||||
+ list_for_each_entry(uprobe, &tmp_list, pending_list) {
|
||||
+ loff_t vaddr = vma_address(vma, uprobe->offset);
|
||||
|
||||
if (vaddr >= start && vaddr < end) {
|
||||
/*
|
||||
@@ -1378,9 +1360,6 @@ void uprobe_free_utask(struct task_struct *t)
|
||||
{
|
||||
struct uprobe_task *utask = t->utask;
|
||||
|
||||
- if (t->uprobe_srcu_id != -1)
|
||||
- srcu_read_unlock_raw(&uprobes_srcu, t->uprobe_srcu_id);
|
||||
-
|
||||
if (!utask)
|
||||
return;
|
||||
|
||||
@@ -1398,7 +1377,6 @@ void uprobe_free_utask(struct task_struct *t)
|
||||
void uprobe_copy_process(struct task_struct *t)
|
||||
{
|
||||
t->utask = NULL;
|
||||
- t->uprobe_srcu_id = -1;
|
||||
}
|
||||
|
||||
/*
|
||||
@@ -1417,7 +1395,6 @@ static struct uprobe_task *add_utask(void)
|
||||
if (unlikely(!utask))
|
||||
return NULL;
|
||||
|
||||
- utask->active_uprobe = NULL;
|
||||
current->utask = utask;
|
||||
return utask;
|
||||
}
|
||||
@@ -1479,41 +1456,64 @@ static bool can_skip_sstep(struct uprobe *uprobe, struct pt_regs *regs)
|
||||
return false;
|
||||
}
|
||||
|
||||
+static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
|
||||
+{
|
||||
+ struct mm_struct *mm = current->mm;
|
||||
+ struct uprobe *uprobe = NULL;
|
||||
+ struct vm_area_struct *vma;
|
||||
+
|
||||
+ down_read(&mm->mmap_sem);
|
||||
+ vma = find_vma(mm, bp_vaddr);
|
||||
+ if (vma && vma->vm_start <= bp_vaddr) {
|
||||
+ if (valid_vma(vma, false)) {
|
||||
+ struct inode *inode;
|
||||
+ loff_t offset;
|
||||
+
|
||||
+ inode = vma->vm_file->f_mapping->host;
|
||||
+ offset = bp_vaddr - vma->vm_start;
|
||||
+ offset += (vma->vm_pgoff << PAGE_SHIFT);
|
||||
+ uprobe = find_uprobe(inode, offset);
|
||||
+ }
|
||||
+
|
||||
+ if (!uprobe)
|
||||
+ *is_swbp = is_swbp_at_addr(mm, bp_vaddr);
|
||||
+ } else {
|
||||
+ *is_swbp = -EFAULT;
|
||||
+ }
|
||||
+ up_read(&mm->mmap_sem);
|
||||
+
|
||||
+ return uprobe;
|
||||
+}
|
||||
+
|
||||
/*
|
||||
* Run handler and ask thread to singlestep.
|
||||
* Ensure all non-fatal signals cannot interrupt thread while it singlesteps.
|
||||
*/
|
||||
static void handle_swbp(struct pt_regs *regs)
|
||||
{
|
||||
- struct vm_area_struct *vma;
|
||||
struct uprobe_task *utask;
|
||||
struct uprobe *uprobe;
|
||||
- struct mm_struct *mm;
|
||||
unsigned long bp_vaddr;
|
||||
+ int uninitialized_var(is_swbp);
|
||||
|
||||
- uprobe = NULL;
|
||||
bp_vaddr = uprobe_get_swbp_addr(regs);
|
||||
- mm = current->mm;
|
||||
- down_read(&mm->mmap_sem);
|
||||
- vma = find_vma(mm, bp_vaddr);
|
||||
-
|
||||
- if (vma && vma->vm_start <= bp_vaddr && valid_vma(vma, false)) {
|
||||
- struct inode *inode;
|
||||
- loff_t offset;
|
||||
-
|
||||
- inode = vma->vm_file->f_mapping->host;
|
||||
- offset = bp_vaddr - vma->vm_start;
|
||||
- offset += (vma->vm_pgoff << PAGE_SHIFT);
|
||||
- uprobe = find_uprobe(inode, offset);
|
||||
- }
|
||||
-
|
||||
- srcu_read_unlock_raw(&uprobes_srcu, current->uprobe_srcu_id);
|
||||
- current->uprobe_srcu_id = -1;
|
||||
- up_read(&mm->mmap_sem);
|
||||
+ uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
|
||||
|
||||
if (!uprobe) {
|
||||
- /* No matching uprobe; signal SIGTRAP. */
|
||||
- send_sig(SIGTRAP, current, 0);
|
||||
+ if (is_swbp > 0) {
|
||||
+ /* No matching uprobe; signal SIGTRAP. */
|
||||
+ send_sig(SIGTRAP, current, 0);
|
||||
+ } else {
|
||||
+ /*
|
||||
+ * Either we raced with uprobe_unregister() or we can't
|
||||
+ * access this memory. The latter is only possible if
|
||||
+ * another thread plays with our ->mm. In both cases
|
||||
+ * we can simply restart. If this vma was unmapped we
|
||||
+ * can pretend this insn was not executed yet and get
|
||||
+ * the (correct) SIGSEGV after restart.
|
||||
+ */
|
||||
+ instruction_pointer_set(regs, bp_vaddr);
|
||||
+ }
|
||||
return;
|
||||
}
|
||||
|
||||
@@ -1620,7 +1620,6 @@ int uprobe_pre_sstep_notifier(struct pt_regs *regs)
|
||||
utask->state = UTASK_BP_HIT;
|
||||
|
||||
set_thread_flag(TIF_UPROBE);
|
||||
- current->uprobe_srcu_id = srcu_read_lock_raw(&uprobes_srcu);
|
||||
|
||||
return 1;
|
||||
}
|
||||
@@ -1655,7 +1654,6 @@ static int __init init_uprobes(void)
|
||||
mutex_init(&uprobes_mutex[i]);
|
||||
mutex_init(&uprobes_mmap_mutex[i]);
|
||||
}
|
||||
- init_srcu_struct(&uprobes_srcu);
|
||||
|
||||
return register_die_notifier(&uprobe_exception_nb);
|
||||
}
|
Loading…
Reference in New Issue
Block a user