kprobes: Update document about irq disabled state in kprobe handler
PATCH 1/2 kprobes: Update document about irq disabled state in kprobe handler
Update kprobes.txt about interrupts disabled state inside kprobes handlers, because optimized probe/boosted kretprobe run without disabling interrrupts on x86.
Signed-off-by Masami Hiramatsu <[email protected]>
Cc Ananth N Mavinakayanahalli <[email protected]>
---
Documentation/kprobes.txt | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-)
Documentation/kprobes.txt +5 -3
@@ -541,9 +541,11 @@ Kprobes does not use mutexes or allocate memory except during registration and unregistration. Probe handlers are run with preemption disabled. Depending on the -architecture, handlers may also run with interrupts disabled. In any -case, your handler should not yield the CPU (e.g., by attempting to -acquire a semaphore). +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). Since a return probe is implemented by replacing the return address with the trampoline's address, stack backtraces and calls
Quoted 6 lines · Masami Hiramatsu
Update kprobes.txt about interrupts disabled state inside kprobes handlers, because optimized probe/boosted kretprobe run without disabling interrrupts on x86.
Signed-off-by Masami Hiramatsu <[email protected]>Cc Ananth N Mavinakayanahalli <[email protected]>
Quoted 27 lines
---
Documentation/kprobes.txt | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-)Documentation/kprobes.txt +5
-3@@ -541,9 +541,11 @@ Kprobes does not use mutexes or allocate memory except during registration and unregistration. Probe handlers are run with preemption disabled. Depending on the -architecture, handlers may also run with interrupts disabled. In any -case, your handler should not yield the CPU (e.g., by attempting to -acquire a semaphore). +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). Since a return probe is implemented by replacing the return address with the trampoline's address, stack backtraces and calls