6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Francois Dugast <francois.dugast@xxxxxxxxx> [ Upstream commit 8ad0e1810bf23f22cedb8a2664548b15646570c7 ] What needs to be asserted is that the pattern fits in the number of bits provided by the user in patternbits, otherwise it would be truncated when replicated according to the mask, which is likely not the intended use of this function. The pattern argument is a bitmap so use find_last_bit() instead of fls(). The bit position starts at index 0 so remove "or equal" from the comparison. XE_MAX_L3_BANK_MASK_BITS would be the returned value if the pattern is 0, which can be the case on some platforms. v2: Check the result does not overflow the array (Lucas De Marchi) v3: Use __fls() for long and handle mask == 0 (Lucas De Marchi) Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Signed-off-by: Francois Dugast <francois.dugast@xxxxxxxxx> Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20240502124311.159695-1-francois.dugast@xxxxxxxxx Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/xe/xe_gt_topology.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_gt_topology.c b/drivers/gpu/drm/xe/xe_gt_topology.c index 3733e7a6860d..d224ed1b5c0f 100644 --- a/drivers/gpu/drm/xe/xe_gt_topology.c +++ b/drivers/gpu/drm/xe/xe_gt_topology.c @@ -108,7 +108,9 @@ gen_l3_mask_from_pattern(struct xe_device *xe, xe_l3_bank_mask_t dst, { unsigned long bit; - xe_assert(xe, fls(mask) <= patternbits); + xe_assert(xe, find_last_bit(pattern, XE_MAX_L3_BANK_MASK_BITS) < patternbits || + bitmap_empty(pattern, XE_MAX_L3_BANK_MASK_BITS)); + xe_assert(xe, !mask || patternbits * (__fls(mask) + 1) <= XE_MAX_L3_BANK_MASK_BITS); for_each_set_bit(bit, &mask, 32) { xe_l3_bank_mask_t shifted_pattern = {}; -- 2.43.0
