Re: [PATCH 1/5] drm/modes: parse_cmdline: Handle empty mode name part
From: Hans de Goede <hidden>
Date: 2022-07-08 19:29:30
Also in:
dri-devel, linux-m68k, lkml
Hi Geert, On 7/8/22 20:21, Geert Uytterhoeven wrote:
If no mode name part was specified, mode_end is zero, and the "ret == mode_end" check does the wrong thing. Fix this by checking for a non-zero return value instead.
Which is wrong to do, since now if you have e.g. a mode list with: "dblntsc", "dblntsc-ff" in there and the cmdline contains "dblntsc-ff" then you will already stop with a (wrong!) match at "dblntsc".
While at it, skip all named mode handling when mode_end is zero, as it is futile.
AFAICT, this is actually what needs to be done to fix this, while keeping the ret == mode_end check. Regards, Hans
quoted hunk ↗ jump to hunk
Fixes: 7b1cce760afe38b4 ("drm/modes: parse_cmdline: Allow specifying stand-alone options") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> --- drivers/gpu/drm/drm_modes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index 14b746f7ba975954..30a7be97707bfb16 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c@@ -1823,9 +1823,9 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option, } /* First check for a named mode */ - for (i = 0; i < ARRAY_SIZE(drm_named_modes_whitelist); i++) { + for (i = 0; mode_end && i < ARRAY_SIZE(drm_named_modes_whitelist); i++) { ret = str_has_prefix(name, drm_named_modes_whitelist[i]); - if (ret == mode_end) { + if (ret) { if (refresh_ptr) return false; /* named + refresh is invalid */