I met below error during boot with i915 builtin if pass "i915.mitigations=off": [ 0.015589] Booting kernel: `off' invalid for parameter `i915.mitigations'
The reason is slab subsystem isn't ready at that time, so kstrdup() returns NULL. Fix this issue by using stack var instead of kstrdup().
Fixes: 984cadea032b ("drm/i915: Allow the sysadmin to override security mitigations") Signed-off-by: Jisheng Zhang Jisheng.Zhang@synaptics.com --- Since v2: - Use strscpy() per Ville's suggestion.
Since v1: - Ensure "str" is properly terminated. Thanks Ville for pointing this out.
drivers/gpu/drm/i915/i915_mitigations.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_mitigations.c b/drivers/gpu/drm/i915/i915_mitigations.c index 84f12598d145..70944764a77e 100644 --- a/drivers/gpu/drm/i915/i915_mitigations.c +++ b/drivers/gpu/drm/i915/i915_mitigations.c @@ -29,15 +29,13 @@ bool i915_mitigate_clear_residuals(void) static int mitigations_set(const char *val, const struct kernel_param *kp) { unsigned long new = ~0UL; - char *str, *sep, *tok; + char str[64], *sep, *tok; bool first = true; int err = 0;
BUILD_BUG_ON(ARRAY_SIZE(names) >= BITS_PER_TYPE(mitigations));
- str = kstrdup(val, GFP_KERNEL); - if (!str) - return -ENOMEM; + strscpy(str, val, sizeof(str));
for (sep = str; (tok = strsep(&sep, ","));) { bool enable = true; @@ -86,7 +84,6 @@ static int mitigations_set(const char *val, const struct kernel_param *kp) break; } } - kfree(str); if (err) return err;