From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@kernel.org>
Cc: X86 ML <x86@kernel.org>, Masami Hiramatsu <mhiramat@kernel.org>,
Daniel Xu <dxu@dxuuu.xyz>,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
kuba@kernel.org, mingo@redhat.com, ast@kernel.org,
tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com,
Josh Poimboeuf <jpoimboe@redhat.com>,
linux-ia64@vger.kernel.org,
Abhishek Sagar <sagar.abhishek@gmail.com>,
Andrii Nakryiko <andrii.nakryiko@gmail.com>
Subject: [PATCH -tip v6 00/13] kprobes: Fix stacktrace with kretprobes on x86
Date: Wed, 26 May 2021 17:02:09 +0900 [thread overview]
Message-ID: <162201612941.278331.5293566981784464165.stgit@devnote2> (raw)
Hello,
Here is the 6th version of the series to fix the stacktrace with kretprobe
on x86.
The previous version is;
https://lore.kernel.org/bpf/161676170650.330141.6214727134265514123.stgit@devnote2/
This version is rebased on the latest tip tree and add some patches for
improving stacktrace[13/13].
Changes from v5:
[02/13]:
- Use dereference_symbol_descriptor() instead of dereference_function_descriptor()
[04/13]:
- Replace BUG_ON() with WARN_ON_ONCE() in __kretprobe_trampoline_handler().
[13/13]:
- Add a new patch to fix return address in earlier stage.
With this series, unwinder can unwind stack correctly from ftrace as below;
# cd /sys/kernel/debug/tracing
# echo > trace
# echo 1 > options/sym-offset
# echo r vfs_read >> kprobe_events
# echo r full_proxy_read >> kprobe_events
# echo traceoff:1 > events/kprobes/r_vfs_read_0/trigger
# echo stacktrace:1 > events/kprobes/r_full_proxy_read_0/trigger
# echo 1 > events/kprobes/enable
# cat /sys/kernel/debug/kprobes/list
ffffffff8133b740 r full_proxy_read+0x0 [FTRACE]
ffffffff812560b0 r vfs_read+0x0 [FTRACE]
# echo 0 > events/kprobes/enable
# cat trace
# tracer: nop
#
# entries-in-buffer/entries-written: 3/3 #P:8
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
<...>-134 [007] ...1 16.185877: r_full_proxy_read_0: (vfs_read+0x98/0x180 <- full_proxy_read)
<...>-134 [007] ...1 16.185901: <stack trace>
=> kretprobe_trace_func+0x209/0x300
=> kretprobe_dispatcher+0x4a/0x70
=> __kretprobe_trampoline_handler+0xd4/0x170
=> trampoline_handler+0x43/0x60
=> kretprobe_trampoline+0x2a/0x50
=> vfs_read+0x98/0x180
=> ksys_read+0x5f/0xe0
=> do_syscall_64+0x37/0x90
=> entry_SYSCALL_64_after_hwframe+0x44/0xae
<...>-134 [007] ...1 16.185902: r_vfs_read_0: (ksys_read+0x5f/0xe0 <- vfs_read)
This shows the double return probes (vfs_read and full_proxy_read) on the stack
correctly unwinded. (vfs_read will return to ksys_read+0x5f and full_proxy_read
will return to vfs_read+0x98)
This actually changes the kretprobe behavisor a bit, now the instraction pointer in
the pt_regs passed to kretprobe user handler is correctly set the real return
address. So user handlers can get it via instruction_pointer() API.
You can also get this series from
git://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git kprobes/kretprobe-stackfix-v6
Thank you,
---
Josh Poimboeuf (1):
x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline code
Masami Hiramatsu (12):
ia64: kprobes: Fix to pass correct trampoline address to the handler
kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_descriptor()
kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()
kprobes: Add kretprobe_find_ret_addr() for searching return address
ARC: Add instruction_pointer_set() API
ia64: Add instruction_pointer_set() API
arm: kprobes: Make a space for regs->ARM_pc at kretprobe_trampoline
kprobes: Setup instruction pointer in __kretprobe_trampoline_handler
x86/kprobes: Push a fake return address at kretprobe_trampoline
x86/unwind: Recover kretprobe trampoline entry
tracing: Show kretprobe unknown indicator only for kretprobe_trampoline
x86/kprobes: Fixup return address in generic trampoline handler
arch/arc/include/asm/ptrace.h | 5 ++
arch/arc/kernel/kprobes.c | 2 -
arch/arm/probes/kprobes/core.c | 5 +-
arch/arm64/kernel/probes/kprobes.c | 3 -
arch/csky/kernel/probes/kprobes.c | 2 -
arch/ia64/include/asm/ptrace.h | 5 ++
arch/ia64/kernel/kprobes.c | 15 ++---
arch/mips/kernel/kprobes.c | 3 -
arch/parisc/kernel/kprobes.c | 4 +
arch/powerpc/kernel/kprobes.c | 13 ----
arch/riscv/kernel/probes/kprobes.c | 2 -
arch/s390/kernel/kprobes.c | 2 -
arch/sh/kernel/kprobes.c | 2 -
arch/sparc/kernel/kprobes.c | 2 -
arch/x86/include/asm/kprobes.h | 1
arch/x86/include/asm/unwind.h | 23 +++++++
arch/x86/include/asm/unwind_hints.h | 5 ++
arch/x86/kernel/kprobes/core.c | 53 +++++++++++++++--
arch/x86/kernel/unwind_frame.c | 4 +
arch/x86/kernel/unwind_guess.c | 3 -
arch/x86/kernel/unwind_orc.c | 19 +++++-
include/linux/kprobes.h | 41 +++++++++++--
kernel/kprobes.c | 108 +++++++++++++++++++++++++----------
kernel/trace/trace_output.c | 17 +-----
lib/error-inject.c | 3 +
25 files changed, 237 insertions(+), 105 deletions(-)
--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>
next reply other threads:[~2021-05-26 8:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-26 8:02 Masami Hiramatsu [this message]
2021-05-26 8:02 ` [PATCH -tip v6 01/13] ia64: kprobes: Fix to pass correct trampoline address to the handler Masami Hiramatsu
2021-05-26 8:02 ` [PATCH -tip v6 02/13] kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_descriptor() Masami Hiramatsu
2021-05-26 8:02 ` [PATCH -tip v6 03/13] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler() Masami Hiramatsu
2021-05-26 8:02 ` [PATCH -tip v6 04/13] kprobes: Add kretprobe_find_ret_addr() for searching return address Masami Hiramatsu
2021-05-26 8:03 ` [PATCH -tip v6 05/13] x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline code Masami Hiramatsu
2021-05-26 8:03 ` [PATCH -tip v6 06/13] ARC: Add instruction_pointer_set() API Masami Hiramatsu
2021-05-26 8:03 ` [PATCH -tip v6 07/13] ia64: " Masami Hiramatsu
2021-05-26 8:03 ` [PATCH -tip v6 08/13] arm: kprobes: Make a space for regs->ARM_pc at kretprobe_trampoline Masami Hiramatsu
2021-05-26 8:03 ` [PATCH -tip v6 09/13] kprobes: Setup instruction pointer in __kretprobe_trampoline_handler Masami Hiramatsu
2021-05-26 8:03 ` [PATCH -tip v6 10/13] x86/kprobes: Push a fake return address at kretprobe_trampoline Masami Hiramatsu
2021-05-26 8:04 ` [PATCH -tip v6 11/13] x86/unwind: Recover kretprobe trampoline entry Masami Hiramatsu
2021-05-26 8:04 ` [PATCH -tip v6 12/13] tracing: Show kretprobe unknown indicator only for kretprobe_trampoline Masami Hiramatsu
2021-05-26 8:04 ` [PATCH -tip v6 13/13] x86/kprobes: Fixup return address in generic trampoline handler Masami Hiramatsu
2021-05-26 17:39 ` [PATCH -tip v6 00/13] kprobes: Fix stacktrace with kretprobes on x86 Andrii Nakryiko
2021-05-27 0:20 ` Masami Hiramatsu
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