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-rw-r--r--Documentation/trace/ftrace-design.txt4
-rw-r--r--kernel/trace/trace_syscalls.c21
2 files changed, 18 insertions, 7 deletions
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt
index 6fca17beee2f..79fcafc7fd64 100644
--- a/Documentation/trace/ftrace-design.txt
+++ b/Documentation/trace/ftrace-design.txt
@@ -250,6 +250,10 @@ You need very few things to get the syscalls tracing in an arch.
- If the system call table on this arch is more complicated than a simple array
of addresses of the system calls, implement an arch_syscall_addr to return
the address of a given system call.
+- If the symbol names of the system calls do not match the function names on
+ this arch, define ARCH_HAS_SYSCALL_MATCH_SYM_NAME in asm/ftrace.h and
+ implement arch_syscall_match_sym_name with the appropriate logic to return
+ true if the function name corresponds with the symbol name.
- Tag this arch as HAVE_SYSCALL_TRACEPOINTS.
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index af831545f656..86a23e7de031 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -60,6 +60,19 @@ extern struct syscall_metadata *__stop_syscalls_metadata[];
static struct syscall_metadata **syscalls_metadata;
+#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
+static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
+{
+ /*
+ * Only compare after the "sys" prefix. Archs that use
+ * syscall wrappers may have syscalls symbols aliases prefixed
+ * with "SyS" instead of "sys", leading to an unwanted
+ * mismatch.
+ */
+ return !strcmp(sym + 3, name + 3);
+}
+#endif
+
static __init struct syscall_metadata *
find_syscall_meta(unsigned long syscall)
{
@@ -73,13 +86,7 @@ find_syscall_meta(unsigned long syscall)
kallsyms_lookup(syscall, NULL, NULL, NULL, str);
for ( ; start < stop; start++) {
- /*
- * Only compare after the "sys" prefix. Archs that use
- * syscall wrappers may have syscalls symbols aliases prefixed
- * with "SyS" instead of "sys", leading to an unwanted
- * mismatch.
- */
- if ((*start)->name && !strcmp((*start)->name + 3, str + 3))
+ if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name))
return *start;
}
return NULL;