iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

arm64: kprobes: Make a frame pointer on __kretprobe_trampoline

Browse Source 
Make a frame pointer (make the x29 register points the
address of pt_regs->regs[29]) on __kretprobe_trampoline.

This frame pointer will be used by the stacktracer when it is
called from the kretprobe handlers. In this case, the stack
tracer will unwind stack to trampoline_probe_handler() and
find the next frame pointer in the stack frame of the
__kretprobe_trampoline().

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2021-10-21 09:55:00 +09:00 committed by Steven Rostedt (VMware)
parent f871741062
commit fc6d647638
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/arm64/kernel/probes/kprobes_trampoline.S
View File

@ -66,6 +66,9 @@ SYM_CODE_START(__kretprobe_trampoline)
save_all_base_regs
/* Setup a frame pointer. */
add x29, sp, #S_FP
mov x0, sp
bl trampoline_probe_handler
/*
@ -74,6 +77,7 @@ SYM_CODE_START(__kretprobe_trampoline)
*/
mov lr, x0
/* The frame pointer (x29) is restored with other registers. */
restore_all_base_regs
add sp, sp, #PT_REGS_SIZE