In preparation for removing the strlcat() API[1], replace its two uses in the generic parser.
Both call sites append one suffix to a string that the function has already bounded to the buffer size. A strscpy() anchored at the current end of the string writes the same bytes, including when the suffix is truncated. Link: https://github.com/KSPP/linux/issues/370 [1] Signed-off-by: Ian Bridges <[email protected]> --- The patch was tested as follows. - W=1 build of sound/hda/, zero warnings. - A userspace differential harness compiled the old and the new functions side by side. The buffers were byte identical over their full length, including the bytes after the terminator. - A QEMU runtime compare. A guest with an emulated HDA codec was booted on the base and on the patched kernel, and the captured /proc/asound state was byte identical. That covers the PCM stream names from fill_pcm_stream_name() live. sound/hda/codecs/generic.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/sound/hda/codecs/generic.c b/sound/hda/codecs/generic.c index 660a9f2c0ded..5f373cbf4a53 100644 --- a/sound/hda/codecs/generic.c +++ b/sound/hda/codecs/generic.c @@ -2712,10 +2712,12 @@ static void get_jack_mode_name(struct hda_codec *codec, hda_nid_t pin, char *name, size_t name_len) { struct hda_gen_spec *spec = codec->spec; + size_t used; int idx = 0; snd_hda_get_pin_label(codec, pin, &spec->autocfg, name, name_len, &idx); - strlcat(name, " Jack Mode", name_len); + used = strnlen(name, name_len); + strscpy(name + used, " Jack Mode", name_len - used); for (; find_kctl_name(codec, name, idx); idx++) ; @@ -5682,6 +5684,7 @@ static const struct hda_pcm_stream dyn_adc_pcm_analog_capture = { static void fill_pcm_stream_name(char *str, size_t len, const char *sfx, const char *chip_name) { + size_t used; char *p; if (*str) @@ -5695,7 +5698,8 @@ static void fill_pcm_stream_name(char *str, size_t len, const char *sfx, break; } } - strlcat(str, sfx, len); + used = strnlen(str, len); + strscpy(str + used, sfx, len - used); } /* copy PCM stream info from @default_str, and override non-NULL entries -- 2.47.3
