linux_dsm_epyc7002/arch/arm/include/asm/ftrace.h
Abel Vesa 620176f335 ARM: 8678/1: ftrace: Adds support for CONFIG_DYNAMIC_FTRACE_WITH_REGS
The DYNAMIC_FTRACE_WITH_REGS configuration makes it possible for a
ftrace operation to specify if registers need to saved/restored by
the ftrace handler. This is needed by kgraft and possibly other
ftrace-based tools, and the ARM architecture is currently lacking
this feature. It would also be the first step to support the
"Kprobes-on-ftrace" optimization on ARM.

This patch introduces a new ftrace handler that stores the registers
on the stack before calling the next stage. The registers are restored
from the stack before going back to the instrumented function.

A side-effect of this patch is to activate the support for
ftrace_modify_call() as it defines ARCH_SUPPORTS_FTRACE_OPS for the
ARM architecture.

Signed-off-by: Abel Vesa <abelvesa@linux.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-06-18 22:25:16 +01:00

82 lines
1.8 KiB
C

#ifndef _ASM_ARM_FTRACE
#define _ASM_ARM_FTRACE
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
#define ARCH_SUPPORTS_FTRACE_OPS 1
#endif
#ifdef CONFIG_FUNCTION_TRACER
#define MCOUNT_ADDR ((unsigned long)(__gnu_mcount_nc))
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
#ifndef __ASSEMBLY__
extern void mcount(void);
extern void __gnu_mcount_nc(void);
#ifdef CONFIG_DYNAMIC_FTRACE
struct dyn_arch_ftrace {
#ifdef CONFIG_OLD_MCOUNT
bool old_mcount;
#endif
};
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
/* With Thumb-2, the recorded addresses have the lsb set */
return addr & ~1;
}
extern void ftrace_caller_old(void);
extern void ftrace_call_old(void);
#endif
#endif
#endif
#ifndef __ASSEMBLY__
#if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND)
/*
* return_address uses walk_stackframe to do it's work. If both
* CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=y walk_stackframe uses unwind
* information. For this to work in the function tracer many functions would
* have to be marked with __notrace. So for now just depend on
* !CONFIG_ARM_UNWIND.
*/
void *return_address(unsigned int);
#else
static inline void *return_address(unsigned int level)
{
return NULL;
}
#endif
#define ftrace_return_address(n) return_address(n)
#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
static inline bool arch_syscall_match_sym_name(const char *sym,
const char *name)
{
if (!strcmp(sym, "sys_mmap2"))
sym = "sys_mmap_pgoff";
else if (!strcmp(sym, "sys_statfs64_wrapper"))
sym = "sys_statfs64";
else if (!strcmp(sym, "sys_fstatfs64_wrapper"))
sym = "sys_fstatfs64";
else if (!strcmp(sym, "sys_arm_fadvise64_64"))
sym = "sys_fadvise64_64";
/* Ignore case since sym may start with "SyS" instead of "sys" */
return !strcasecmp(sym, name);
}
#endif /* ifndef __ASSEMBLY__ */
#endif /* _ASM_ARM_FTRACE */