linux/arch/arm64/include/asm/ftrace.h
Masami Hiramatsu 874bfc6e54 arm64: ftrace: Fix to enable syscall events on arm64
Since commit 4378a7d4be ("arm64: implement syscall wrappers")
introduced "__arm64_" prefix to all syscall wrapper symbols in
sys_call_table, syscall tracer can not find corresponding
metadata from syscall name. In the result, we have no syscall
ftrace events on arm64 kernel, and some bpf testcases are failed
on arm64.

To fix this issue, this introduces custom
arch_syscall_match_sym_name() which skips first 8 bytes when
comparing the syscall and symbol names.

Fixes: 4378a7d4be ("arm64: implement syscall wrappers")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-11-29 16:53:10 +00:00

75 lines
1.9 KiB
C

/*
* arch/arm64/include/asm/ftrace.h
*
* Copyright (C) 2013 Linaro Limited
* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_FTRACE_H
#define __ASM_FTRACE_H
#include <asm/insn.h>
#define MCOUNT_ADDR ((unsigned long)_mcount)
#define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
#ifndef __ASSEMBLY__
#include <linux/compat.h>
extern void _mcount(unsigned long);
extern void *return_address(unsigned int);
struct dyn_arch_ftrace {
/* No extra data needed for arm64 */
};
extern unsigned long ftrace_graph_call;
extern void return_to_handler(void);
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;
}
#define ftrace_return_address(n) return_address(n)
/*
* Because AArch32 mode does not share the same syscall table with AArch64,
* tracing compat syscalls may result in reporting bogus syscalls or even
* hang-up, so just do not trace them.
* See kernel/trace/trace_syscalls.c
*
* x86 code says:
* If the user really wants these, then they should use the
* raw syscall tracepoints with filtering.
*/
#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
{
return is_compat_task();
}
#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
static inline bool arch_syscall_match_sym_name(const char *sym,
const char *name)
{
/*
* Since all syscall functions have __arm64_ prefix, we must skip it.
* However, as we described above, we decided to ignore compat
* syscalls, so we don't care about __arm64_compat_ prefix here.
*/
return !strcmp(sym + 8, name);
}
#endif /* ifndef __ASSEMBLY__ */
#endif /* __ASM_FTRACE_H */