mirror of
https://github.com/torvalds/linux
synced 2024-10-28 06:09:03 +00:00
08d636b6d4
This method changes x86 to add a breakpoint to the mcount locations instead of calling stop machine. Now that iret can be handled by NMIs, we perform the following to update code: 1) Add a breakpoint to all locations that will be modified 2) Sync all cores 3) Update all locations to be either a nop or call (except breakpoint op) 4) Sync all cores 5) Remove the breakpoint with the new code. 6) Sync all cores [ Added updates that Masami suggested: Use unlikely(modifying_ftrace_code) in int3 trap to keep kprobes efficient. Don't use NOTIFY_* in ftrace handler in int3 as it is not a notifier. ] Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
61 lines
1.2 KiB
C
61 lines
1.2 KiB
C
#ifndef _ASM_X86_FTRACE_H
|
|
#define _ASM_X86_FTRACE_H
|
|
|
|
#ifdef __ASSEMBLY__
|
|
|
|
.macro MCOUNT_SAVE_FRAME
|
|
/* taken from glibc */
|
|
subq $0x38, %rsp
|
|
movq %rax, (%rsp)
|
|
movq %rcx, 8(%rsp)
|
|
movq %rdx, 16(%rsp)
|
|
movq %rsi, 24(%rsp)
|
|
movq %rdi, 32(%rsp)
|
|
movq %r8, 40(%rsp)
|
|
movq %r9, 48(%rsp)
|
|
.endm
|
|
|
|
.macro MCOUNT_RESTORE_FRAME
|
|
movq 48(%rsp), %r9
|
|
movq 40(%rsp), %r8
|
|
movq 32(%rsp), %rdi
|
|
movq 24(%rsp), %rsi
|
|
movq 16(%rsp), %rdx
|
|
movq 8(%rsp), %rcx
|
|
movq (%rsp), %rax
|
|
addq $0x38, %rsp
|
|
.endm
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
#define MCOUNT_ADDR ((long)(mcount))
|
|
#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
|
|
|
|
#ifndef __ASSEMBLY__
|
|
extern void mcount(void);
|
|
extern int modifying_ftrace_code;
|
|
|
|
static inline unsigned long ftrace_call_adjust(unsigned long addr)
|
|
{
|
|
/*
|
|
* addr is the address of the mcount call instruction.
|
|
* recordmcount does the necessary offset calculation.
|
|
*/
|
|
return addr;
|
|
}
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
struct dyn_arch_ftrace {
|
|
/* No extra data needed for x86 */
|
|
};
|
|
|
|
int ftrace_int3_handler(struct pt_regs *regs);
|
|
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
#endif /* __ASSEMBLY__ */
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|
|
|
|
#endif /* _ASM_X86_FTRACE_H */
|