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authorFlorent Revest <revest@chromium.org>2023-04-27 17:06:59 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-07-23 14:49:44 +0300
commite2c7a05a48e589af6153718b046dd9cd1d38854b (patch)
treeb5e1a59ff76bce7156962b62564943bb462d65c8 /samples/ftrace
parent9d6a260bbfbc606bfd5089afc080b0e068be6ac0 (diff)
downloadlinux-e2c7a05a48e589af6153718b046dd9cd1d38854b.tar.xz
samples: ftrace: Save required argument registers in sample trampolines
commit 8564c315876ab86fcaf8e7f558d6a84cb2ce5590 upstream. The ftrace-direct-too sample traces the handle_mm_fault function whose signature changed since the introduction of the sample. Since: commit bce617edecad ("mm: do page fault accounting in handle_mm_fault") handle_mm_fault now has 4 arguments. Therefore, the sample trampoline should save 4 argument registers. s390 saves all argument registers already so it does not need a change but x86_64 needs an extra push and pop. This also evolves the signature of the tracing function to make it mirror the signature of the traced function. Link: https://lkml.kernel.org/r/20230427140700.625241-2-revest@chromium.org Cc: stable@vger.kernel.org Fixes: bce617edecad ("mm: do page fault accounting in handle_mm_fault") Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'samples/ftrace')
-rw-r--r--samples/ftrace/ftrace-direct-too.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 6690468c5cc2..14c6859e1ac4 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -5,14 +5,14 @@
#include <linux/ftrace.h>
#include <asm/asm-offsets.h>
-extern void my_direct_func(struct vm_area_struct *vma,
- unsigned long address, unsigned int flags);
+extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,
+ unsigned int flags, struct pt_regs *regs);
-void my_direct_func(struct vm_area_struct *vma,
- unsigned long address, unsigned int flags)
+void my_direct_func(struct vm_area_struct *vma, unsigned long address,
+ unsigned int flags, struct pt_regs *regs)
{
- trace_printk("handle mm fault vma=%p address=%lx flags=%x\n",
- vma, address, flags);
+ trace_printk("handle mm fault vma=%p address=%lx flags=%x regs=%p\n",
+ vma, address, flags, regs);
}
extern void my_tramp(void *);
@@ -32,7 +32,9 @@ asm (
" pushq %rdi\n"
" pushq %rsi\n"
" pushq %rdx\n"
+" pushq %rcx\n"
" call my_direct_func\n"
+" popq %rcx\n"
" popq %rdx\n"
" popq %rsi\n"
" popq %rdi\n"