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.zh...@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;
 
-- 
2.31.0

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to