[PATCH for v4.9 LTS 81/87] ARM: 8632/1: ftrace: fix syscall name matching

From: Levin, Alexander (Sasha Levin)
Date: Fri Jul 14 2017 - 21:31:42 EST


From: Rabin Vincent <rabinv@xxxxxxxx>

[ Upstream commit 270c8cf1cacc69cb8d99dea812f06067a45e4609 ]

ARM has a few system calls (most notably mmap) for which the names of
the functions which are referenced in the syscall table do not match the
names of the syscall tracepoints. As a consequence of this, these
tracepoints are not made available. Implement
arch_syscall_match_sym_name to fix this and allow tracing even these
system calls.

Signed-off-by: Rabin Vincent <rabinv@xxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
arch/arm/include/asm/ftrace.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
index bfe2a2f5a644..22b73112b75f 100644
--- a/arch/arm/include/asm/ftrace.h
+++ b/arch/arm/include/asm/ftrace.h
@@ -54,6 +54,24 @@ static inline void *return_address(unsigned int level)

#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 */
--
2.11.0