Revision tags: v6.6.36, v6.6.35, v6.6.34, v6.6.33, v6.6.32, v6.6.31, v6.6.30 |
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ae0d1ea3 |
| 01-May-2024 |
Stephen Brennan <stephen.s.brennan@oracle.com> |
kprobe/ftrace: bail out if ftrace was killed
[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ]
If an error happens in ftrace, ftrace_kill() will prevent disarming kprobes. Eventually, th
kprobe/ftrace: bail out if ftrace was killed
[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ]
If an error happens in ftrace, ftrace_kill() will prevent disarming kprobes. Eventually, the ftrace_ops associated with the kprobes will be freed, yet the kprobes will still be active, and when triggered, they will use the freed memory, likely resulting in a page fault and panic.
This behavior can be reproduced quite easily, by creating a kprobe and then triggering a ftrace_kill(). For simplicity, we can simulate an ftrace error with a kernel module like [1]:
[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer
sudo perf probe --add commit_creds sudo perf trace -e probe:commit_creds # In another terminal make sudo insmod ftrace_killer.ko # calls ftrace_kill(), simulating bug # Back to perf terminal # ctrl-c sudo perf probe --del commit_creds
After a short period, a page fault and panic would occur as the kprobe continues to execute and uses the freed ftrace_ops. While ftrace_kill() is supposed to be used only in extreme circumstances, it is invoked in FTRACE_WARN_ON() and so there are many places where an unexpected bug could be triggered, yet the system may continue operating, possibly without the administrator noticing. If ftrace_kill() does not panic the system, then we should do everything we can to continue operating, rather than leave a ticking time bomb.
Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Guo Ren <guoren@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Revision tags: v6.6.29, v6.6.28, v6.6.27, v6.6.26, v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3, v6.5.2, v6.1.51, v6.5.1, v6.1.50, v6.5, v6.1.49, v6.1.48, v6.1.46, v6.1.45, v6.1.44, v6.1.43, v6.1.42, v6.1.41, v6.1.40, v6.1.39, v6.1.38, v6.1.37, v6.1.36, v6.4, v6.1.35, v6.1.34, v6.1.33, v6.1.32, v6.1.31, v6.1.30, v6.1.29, v6.1.28, v6.1.27, v6.1.26, v6.3, v6.1.25, v6.1.24, v6.1.23, v6.1.22, v6.1.21, v6.1.20, v6.1.19, v6.1.18, v6.1.17, v6.1.16, v6.1.15, v6.1.14, v6.1.13, v6.2, v6.1.12, v6.1.11, v6.1.10, v6.1.9, v6.1.8, v6.1.7, v6.1.6, v6.1.5, v6.0.19, v6.0.18, v6.1.4, v6.1.3, v6.0.17, v6.1.2, v6.0.16, v6.1.1, v6.0.15, v6.0.14, v6.0.13, v6.1, v6.0.12, v6.0.11, v6.0.10, v5.15.80, v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71, v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66, v5.15.65, v5.15.64, v5.15.63, v5.15.62, v5.15.61, v5.15.60, v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47, v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35, v5.15.34, v5.15.33, v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27, v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20, v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15, v5.16, v5.15.10, v5.15.9, v5.15.8, v5.15.7, v5.15.6, v5.15.5, v5.15.4, v5.15.3, v5.15.2, v5.15.1, v5.15 |
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ce5e4803 |
| 26-Oct-2021 |
王贇 <yun.wang@linux.alibaba.com> |
ftrace: disable preemption when recursion locked
As the documentation explained, ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() were supposed to disable and enable preemption pro
ftrace: disable preemption when recursion locked
As the documentation explained, ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() were supposed to disable and enable preemption properly, however currently this work is done outside of the function, which could be missing by mistake.
And since the internal using of trace_test_and_set_recursion() and trace_clear_recursion() also require preemption disabled, we can just merge the logical.
This patch will make sure the preemption has been disabled when trace_test_and_set_recursion() return bit >= 0, and trace_clear_recursion() will enable the preemption if previously enabled.
Link: https://lkml.kernel.org/r/13bde807-779c-aa4c-0672-20515ae365ea@linux.alibaba.com
CC: Petr Mladek <pmladek@suse.com> Cc: Guo Ren <guoren@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Jisheng Zhang <jszhang@kernel.org> CC: Steven Rostedt <rostedt@goodmis.org> CC: Miroslav Benes <mbenes@suse.cz> Reported-by: Abaci <abaci@linux.alibaba.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com> [ Removed extra line in comment - SDR ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Revision tags: v5.14.14, v5.14.13, v5.14.12, v5.14.11, v5.14.10, v5.14.9, v5.14.8, v5.14.7, v5.14.6, v5.10.67, v5.10.66, v5.14.5, v5.14.4, v5.10.65, v5.14.3, v5.10.64, v5.14.2, v5.10.63, v5.14.1, v5.10.62, v5.14, v5.10.61, v5.10.60, v5.10.53, v5.10.52, v5.10.51, v5.10.50, v5.10.49, v5.13, v5.10.46, v5.10.43, v5.10.42, v5.10.41, v5.10.40, v5.10.39, v5.4.119, v5.10.36, v5.10.35, v5.10.34, v5.4.116, v5.10.33, v5.12, v5.10.32, v5.10.31, v5.10.30, v5.10.27 |
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#
e31be8d3 |
| 29-Mar-2021 |
Jisheng Zhang <jszhang@kernel.org> |
riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
Currently, the riscv's kprobes(powerred by ftrace) handler is preemptible. Futher check indicates we miss something similar as
riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
Currently, the riscv's kprobes(powerred by ftrace) handler is preemptible. Futher check indicates we miss something similar as the commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the ftrace callback"), so do similar modifications as the commit does.
Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported") Cc: stable@vger.kernel.org Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Revision tags: v5.10.26, v5.10.25, v5.10.24, v5.10.23 |
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e0196ae7 |
| 11-Mar-2021 |
Colin Ian King <colin.king@canonical.com> |
ftrace: Fix spelling mistake "disabed" -> "disabled"
There is a spelling mistake in a comment, fix it.
Link: https://lkml.kernel.org/r/20210311094022.5978-1-colin.king@canonical.com
Signed-off-by:
ftrace: Fix spelling mistake "disabed" -> "disabled"
There is a spelling mistake in a comment, fix it.
Link: https://lkml.kernel.org/r/20210311094022.5978-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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bab1770a |
| 11-Mar-2021 |
Colin Ian King <colin.king@canonical.com> |
ftrace: Fix spelling mistake "disabed" -> "disabled"
There is a spelling mistake in a comment, fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Palmer Dabbelt <palmer
ftrace: Fix spelling mistake "disabed" -> "disabled"
There is a spelling mistake in a comment, fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Revision tags: v5.10.22, v5.10.21 |
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288f6775 |
| 05-Mar-2021 |
Nanyong Sun <sunnanyong@huawei.com> |
riscv: ftrace: Use ftrace_get_regs helper
Use ftrace_get_regs() helper call to get pt_regs from ftrace_regs struct, this makes the code simpler.
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> S
riscv: ftrace: Use ftrace_get_regs helper
Use ftrace_get_regs() helper call to get pt_regs from ftrace_regs struct, this makes the code simpler.
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Revision tags: v5.10.20, v5.10.19, v5.4.101, v5.10.18, v5.10.17, v5.11, v5.10.16, v5.10.15, v5.10.14 |
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829adda5 |
| 17-Dec-2020 |
Guo Ren <guoren@linux.alibaba.com> |
riscv: Add KPROBES_ON_FTRACE supported
This patch adds support for kprobes on ftrace call sites to avoids much of the overhead with regular kprobes. Try it with simple steps:
echo 'p:myprobe sys_c
riscv: Add KPROBES_ON_FTRACE supported
This patch adds support for kprobes on ftrace call sites to avoids much of the overhead with regular kprobes. Try it with simple steps:
echo 'p:myprobe sys_clone a0=%a0 a1=%a1 stack_val=+4($stack)' > /sys/kernel/de bug/tracing/kprobe_events echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable cat /sys/kernel/debug/tracing/trace tracer: nop
entries-in-buffer/entries-written: 1/1 #P:1
_-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU# |||| TIMESTAMP FUNCTION | | | |||| | | sh-92 [000] .... 369.899962: myprobe: (sys_clone+0x0/0x28) a0=0x1200011 a1=0x0 stack_val=0x201c20ffffffe0 cat /sys/kernel/debug/kprobes/list ffffffe00020b584 k sys_clone+0x0 [FTRACE] ^^^^^^
Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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