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ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr

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This introduces ftrace_get_symaddr() which tries to convert fentry_ip
passed by ftrace or fgraph callback to symaddr without calling
kallsyms API. It returns the symbol address or 0 if it fails to
convert it.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173519011487.391279.5450806886342723151.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412061423.K79V55Hd-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202412061804.5VRzF14E-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu (Google)
2024-12-26 14:15:14 +09:00
committed by Steven Rostedt (Google)
parent 54b6b4a3d4
commit 2bc56fdae1
4 changed files with 99 additions and 0 deletions
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21
arch/x86/include/asm/ftrace.h
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@@ -34,6 +34,27 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
return addr;
}
static inline unsigned long arch_ftrace_get_symaddr(unsigned long fentry_ip)
{
#ifdef CONFIG_X86_KERNEL_IBT
u32 instr;
/* We want to be extra safe in case entry ip is on the page edge,
* but otherwise we need to avoid get_kernel_nofault()'s overhead.
*/
if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) {
if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE)))
return fentry_ip;
} else {
instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE);
}
if (is_endbr(instr))
fentry_ip -= ENDBR_INSN_SIZE;
#endif
return fentry_ip;
}
#define ftrace_get_symaddr(fentry_ip) arch_ftrace_get_symaddr(fentry_ip)
#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
#include <linux/ftrace_regs.h>