powerpc/ftrace: fix syscall tracing on PPC64_ELF_ABI_V1

In v5.7 the powerpc syscall entry/exit logic was rewritten in C, on
PPC64_ELF_ABI_V1 this resulted in the symbols in the syscall table
changing from their dot prefixed variant to the non-prefixed ones.

Since ftrace prefixes a dot to the syscall names when matching them to
build its syscall event list, this resulted in no syscall events being
available.

Remove the PPC64_ELF_ABI_V1 specific version of
arch_syscall_match_sym_name to have the same behavior across all powerpc
variants.

Fixes: 68b34588 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221201161442.2127231-1-mjeanson@efficios.com

arch/powerpc/include/asm/ftrace.h

@@ -71,17 +71,6 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
  * those.
  */
 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
-#ifdef CONFIG_PPC64_ELF_ABI_V1
-static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
-{
-	/* We need to skip past the initial dot, and the __se_sys alias */
-	return !strcmp(sym + 1, name) ||
-		(!strncmp(sym, ".__se_sys", 9) && !strcmp(sym + 6, name)) ||
-		(!strncmp(sym, ".ppc_", 5) && !strcmp(sym + 5, name + 4)) ||
-		(!strncmp(sym, ".ppc32_", 7) && !strcmp(sym + 7, name + 4)) ||
-		(!strncmp(sym, ".ppc64_", 7) && !strcmp(sym + 7, name + 4));
-}
-#else
 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
 {
 	return !strcmp(sym, name) ||
@@ -90,7 +79,6 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
 		(!strncmp(sym, "ppc32_", 6) && !strcmp(sym + 6, name + 4)) ||
 		(!strncmp(sym, "ppc64_", 6) && !strcmp(sym + 6, name + 4));
 }
-#endif /* CONFIG_PPC64_ELF_ABI_V1 */
 #endif /* CONFIG_FTRACE_SYSCALLS */
 
 #if defined(CONFIG_PPC64) && defined(CONFIG_FUNCTION_TRACER)