[PATCH 1/1] perf lzma: Convert some pr_err() to pr_debug() as callers already use pr_debug()

From: Arnaldo Carvalho de Melo
Date: Tue Aug 22 2023 - 14:52:09 EST


I noticed some error with:

# perf list ex_ret_brn
lzma: fopen failed on /usr/lib/modules/5.15.14-100.fc34.x86_64/kernel/net/bluetooth/bnep/bnep.ko.xz: 'No such file or directory'
lzma: fopen failed on /usr/lib/modules/5.16.16-200.fc35.x86_64/kernel/drivers/gpu/drm/drm_kms_helper.ko.xz: 'No such file or directory'
lzma: fopen failed on /usr/lib/modules/5.18.16-200.fc36.x86_64/kernel/arch/x86/crypto/crct10dif-pclmul.ko.xz: 'No such file or directory'
lzma: fopen failed on /usr/lib/modules/5.16.16-200.fc35.x86_64/kernel/drivers/i2c/busses/i2c-piix4.ko.xz: 'No such file or directory'
<BIG SNIP>

Then using 'perf probe' + 'perf trace' to debug 'perf list', it seems
its some inconsistency in the ~/.debug/ cache where broken build id
symlinks that ends up making it try to uncompress some kernel modules
using the lzma routines:

395.309 perf/3594447 probe_perf:lzma_decompress_to_file(__probe_ip: 6118448, input_string: "/usr/lib/modules/5.18.17-200.fc36.x86_64/kernel/drivers/nvme/host/nvme.ko.xz")
lzma_decompress_to_file (/var/home/acme/bin/perf)
filename__decompress (/var/home/acme/bin/perf)
filename__read_build_id (/var/home/acme/bin/perf)
filename__sprintf_build_id (inlined)
build_id_cache__valid_id (inlined)
build_id_cache__list_all (/var/home/acme/bin/perf)
print_sdt_events (/var/home/acme/bin/perf)
cmd_list (/var/home/acme/bin/perf)
run_builtin (/var/home/acme/bin/perf)
handle_internal_command (inlined)
run_argv (inlined)
main (/var/home/acme/bin/perf)
__libc_start_call_main (/usr/lib64/libc.so.6)
__libc_start_main@@GLIBC_2.34 (/usr/lib64/libc.so.6)
_start (/var/home/acme/bin/perf)

But callers of filename__decompress() already check its return and use
pr_debug(), so be consistent and make functions it calls also use
pr_debug().

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/lzma.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/lzma.c b/tools/perf/util/lzma.c
index 51424cdc3b682c64..af9a97612f9df392 100644
--- a/tools/perf/util/lzma.c
+++ b/tools/perf/util/lzma.c
@@ -45,15 +45,13 @@ int lzma_decompress_to_file(const char *input, int output_fd)

infile = fopen(input, "rb");
if (!infile) {
- pr_err("lzma: fopen failed on %s: '%s'\n",
- input, strerror(errno));
+ pr_debug("lzma: fopen failed on %s: '%s'\n", input, strerror(errno));
return -1;
}

ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
if (ret != LZMA_OK) {
- pr_err("lzma: lzma_stream_decoder failed %s (%d)\n",
- lzma_strerror(ret), ret);
+ pr_debug("lzma: lzma_stream_decoder failed %s (%d)\n", lzma_strerror(ret), ret);
goto err_fclose;
}

@@ -68,7 +66,7 @@ int lzma_decompress_to_file(const char *input, int output_fd)
strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);

if (ferror(infile)) {
- pr_err("lzma: read error: %s\n", strerror(errno));
+ pr_debug("lzma: read error: %s\n", strerror(errno));
goto err_lzma_end;
}

@@ -82,7 +80,7 @@ int lzma_decompress_to_file(const char *input, int output_fd)
ssize_t write_size = sizeof(buf_out) - strm.avail_out;

if (writen(output_fd, buf_out, write_size) != write_size) {
- pr_err("lzma: write error: %s\n", strerror(errno));
+ pr_debug("lzma: write error: %s\n", strerror(errno));
goto err_lzma_end;
}

@@ -94,7 +92,7 @@ int lzma_decompress_to_file(const char *input, int output_fd)
if (ret == LZMA_STREAM_END)
break;

- pr_err("lzma: failed %s\n", lzma_strerror(ret));
+ pr_debug("lzma: failed %s\n", lzma_strerror(ret));
goto err_lzma_end;
}
}
--
2.37.1