diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2018-06-20 01:16:17 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-06-21 12:33:20 +0200 |
| commit | 2bbda764d720aacabaad38374d26fcccb7843f17 (patch) | |
| tree | 25d60c92825b75c73362b455baafb5464aca07cc /Documentation | |
| parent | cce188bd58cfbd603b904dbce75f34de2eff959a (diff) | |
| download | linux-2bbda764d720aacabaad38374d26fcccb7843f17.tar.bz2 | |
kprobes/x86: Do not disable preempt on int3 path
Since int3 and debug exception(for singlestep) are run with
IRQ disabled and while running single stepping we drop IF
from regs->flags, that path must not be preemptible. So we
can remove the preempt disable/enable calls from that path.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942497779.15209.2879580696589868291.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kprobes.txt | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt index ab2c7307f123..cbb545910634 100644 --- a/Documentation/kprobes.txt +++ b/Documentation/kprobes.txt @@ -566,12 +566,11 @@ the same handler) may run concurrently on different CPUs. Kprobes does not use mutexes or allocate memory except during registration and unregistration. -Probe handlers are run with preemption disabled. Depending on the -architecture and optimization state, handlers may also run with -interrupts disabled (e.g., kretprobe handlers and optimized kprobe -handlers run without interrupt disabled on x86/x86-64). In any case, -your handler should not yield the CPU (e.g., by attempting to acquire -a semaphore). +Probe handlers are run with preemption disabled or interrupt disabled, +which depends on the architecture and optimization state. (e.g., +kretprobe handlers and optimized kprobe handlers run without interrupt +disabled on x86/x86-64). In any case, your handler should not yield +the CPU (e.g., by attempting to acquire a semaphore, or waiting I/O). Since a return probe is implemented by replacing the return address with the trampoline's address, stack backtraces and calls |