[PATCH] perf syscalltbl: Add syscalltbl__id_at_idx() with no syscall table support

From: Charlie Jenkins <charlie@rivosinc.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	 Arnaldo Carvalho de Melo <acme@kernel.org>,
	 Namhyung Kim <namhyung@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	 Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	 Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	 Adrian Hunter <adrian.hunter@intel.com>,
	 Paul Walmsley <paul.walmsley@sifive.com>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	 Howard Chu <howardchu95@gmail.com>,
	 David Abdurachmanov <davidlt@rivosinc.com>
Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	 linux-riscv@lists.infradead.org,
	Charlie Jenkins <charlie@rivosinc.com>
Subject: [PATCH] perf syscalltbl: Add syscalltbl__id_at_idx() with no syscall table support
Date: Fri, 30 Aug 2024 21:30:50 -0700	[thread overview]
Message-ID: <20240830-perf_syscalltbl_fix-v1-1-e2ff61ee5e8e@rivosinc.com> (raw)

When HAVE_SYSCALL_TABLE_SUPPORT is not defined, neither is
syscalltbl__id_at_idx(). However, this function is expected to be
defined when HAVE_BPF_SKEL is defined.

Return -1 from syscalltbl__id_at_idx() to match the other functions when
HAVE_SYSCALL_TABLE_SUPPORT is not defined.

Without this, compiling perf on riscv when libtraceevents, libelf, and
clang are available will cause the functions trying to call
syscalltbl__id_at_idx() to be compiled. This results in the following
error:

/usr/bin/ld: perf-in.o: in function `.L0 ':
builtin-trace.c:(.text+0x60b14): undefined reference to `syscalltbl__id_at_idx'
/usr/bin/ld: builtin-trace.c:(.text+0x60c6c): undefined reference to `syscalltbl__id_at_idx'
/usr/bin/ld: perf-in.o: in function `.L2564':
builtin-trace.c:(.text+0x60cb6): undefined reference to `syscalltbl__id_at_idx'
collect2: error: ld returned 1 exit status
make[2]: *** [Makefile.perf:793: perf] Error 1
make[1]: *** [Makefile.perf:290: sub-make] Error 2
make: *** [Makefile:70: all] Error 2
make: Leaving directory '/src/linux-6.11-rc5/tools/perf'

This patch resolves this issue for all architectures which do not define
HAVE_SYSCALL_TABLE_SUPPORT.

$ ./perf trace -e syscalls:sys_enter_mmap --max-events=1 ls
0.000 ls/287 syscalls:sys_enter_mmap(__syscall_nr: 222, len: 9939, prot: READ, flags: PRIVATE, fd: 3)

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reported-by: David Abdurachmanov <davidlt@rivosinc.com>
Suggested-by: David Abdurachmanov <davidlt@rivosinc.com>
Fixes: 7a2fb5619cc1 ("perf trace: Fix iteration of syscall ids in syscalltbl->entries")
---
 tools/perf/util/syscalltbl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/perf/util/syscalltbl.c b/tools/perf/util/syscalltbl.c
index 0dd26b991b3f..12654460428f 100644
--- a/tools/perf/util/syscalltbl.c
+++ b/tools/perf/util/syscalltbl.c
@@ -188,4 +188,9 @@ int syscalltbl__strglobmatch_first(struct syscalltbl *tbl, const char *syscall_g
 {
 	return syscalltbl__strglobmatch_next(tbl, syscall_glob, idx);
 }
+
+int syscalltbl__id_at_idx(struct syscalltbl *tbl __always_unused, int idx __always_unused)
+{
+	return -1;
+}
 #endif /* HAVE_SYSCALL_TABLE_SUPPORT */

---
base-commit: 985bf40edf4343dcb04c33f58b40b4a85c1776d4
change-id: 20240830-perf_syscalltbl_fix-4f586221795e
-- 
- Charlie


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