Re: [PATCH] drm/amd/powerplay: ensure loop does not wraparound on decrement
Am 17.05.2017 20:13, schrieb Colin King: > From: Colin Ian King> > The current for loop decrements i when it is zero and this causes > a wrap-around back to ~0 because i is unsigned. In the unlikely event > that mask is 0, the loop will run forever. Fix this so we can't loop > forever. > > Detected by CoverityScan, CID#1435469 ("Unsigned compared against 0") > > Signed-off-by: Colin Ian King > --- > drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c > b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c > index ad30f5d3a10d..d92c9b9b15be 100644 > --- a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c > +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c > @@ -4199,7 +4199,7 @@ static int vega10_force_clock_level(struct pp_hwmgr > *hwmgr, > } > data->smc_state_table.gfx_boot_level = i; > > - for (i = 31; i >= 0; i--) { > + for (i = 32; --i; ) { > if (mask & (1 << i)) > break; > } nitpicking: we notices at several points that programmers are bad at counting backwards. Is there a reason not to start with i=0 ? re, wh ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
[PATCH] drm/amd/powerplay: ensure loop does not wraparound on decrement
From: Colin Ian KingThe current for loop decrements i when it is zero and this causes a wrap-around back to ~0 because i is unsigned. In the unlikely event that mask is 0, the loop will run forever. Fix this so we can't loop forever. Detected by CoverityScan, CID#1435469 ("Unsigned compared against 0") Signed-off-by: Colin Ian King --- drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c index ad30f5d3a10d..d92c9b9b15be 100644 --- a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c @@ -4199,7 +4199,7 @@ static int vega10_force_clock_level(struct pp_hwmgr *hwmgr, } data->smc_state_table.gfx_boot_level = i; - for (i = 31; i >= 0; i--) { + for (i = 32; --i; ) { if (mask & (1 << i)) break; } -- 2.11.0 ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
Re: [PATCH] drm/amd/powerplay: ensure loop does not wraparound on decrement
I sent a patch for this bug earlier. There is a second bug later in the function which my patch fixes as well. regards, dan carpenter ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx