Patch "perf trace: Return error if a system call doesn't exist" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    perf trace: Return error if a system call doesn't exist

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-trace-return-error-if-a-system-call-doesn-t-exi.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6dca143c4508299a9094ac0d173d07e529294c23
Author: Leo Yan <leo.yan@xxxxxxxxxx>
Date:   Mon Nov 21 07:52:34 2022 +0000

    perf trace: Return error if a system call doesn't exist
    
    [ Upstream commit d4223e1776c30b2ce8d0e6eaadcbf696e60fca3c ]
    
    When a system call is not detected, the reason is either because the
    system call ID is out of scope or failure to find the corresponding path
    in the sysfs, trace__read_syscall_info() returns zero.  Finally, without
    returning an error value it introduces confusion for the caller.
    
    This patch lets the function trace__read_syscall_info() to return
    -EEXIST when a system call doesn't exist.
    
    Fixes: b8b1033fcaa091d8 ("perf trace: Mark syscall ids that are not allocated to avoid unnecessary error messages")
    Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
    Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
    Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
    Cc: bpf@xxxxxxxxxxxxxxx
    Cc: Ingo Molnar <mingo@xxxxxxxxxx>
    Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
    Cc: Mark Rutland <mark.rutland@xxxxxxx>
    Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
    Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20221121075237.127706-3-leo.yan@xxxxxxxxxx
    Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index de80534473af..555e16d8d55b 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1774,11 +1774,11 @@ static int trace__read_syscall_info(struct trace *trace, int id)
 #endif
 	sc = trace->syscalls.table + id;
 	if (sc->nonexistent)
-		return 0;
+		return -EEXIST;
 
 	if (name == NULL) {
 		sc->nonexistent = true;
-		return 0;
+		return -EEXIST;
 	}
 
 	sc->name = name;