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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2017-01-30 16:47:21 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-01-31 14:19:23 +0300 |
| commit | 1692cd60d999b00a0491692dab0286e6011abd36 (patch) | |
| tree | 6ca4aad3e28794cb99b9bdc28dfa993054b6c5f1 /drivers | |
| parent | c88473878d47131ccfc67a00ba688d4d7d0f4519 (diff) | |
| download | linux-1692cd60d999b00a0491692dab0286e6011abd36.tar.xz | |
drm/i915: Sanity check the computed size and base of stolen memory
Just do a quick check that the stolen memory address range doesn't
overflow our chosen integer type.
v2: Add add_overflows() to utils with the promise that gcc7 can do this
better than C and then maybe it will have a proper definition in core.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170130134721.5159-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_stolen.c | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/i915_utils.h | 11 |
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index a75de8c6ece0..cba12ee90cbf 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -189,7 +189,7 @@ static dma_addr_t i915_stolen_to_dma(struct drm_i915_private *dev_priv) base = tom - tseg_size - ggtt->stolen_size; } - if (base == 0) + if (base == 0 || add_overflows(base, ggtt->stolen_size)) return 0; /* make sure we don't clobber the GTT if it's within stolen memory */ diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index 34020873e1f6..b8ba0f2f92af 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -25,6 +25,17 @@ #ifndef __I915_UTILS_H #define __I915_UTILS_H +#if GCC_VERSION >= 70000 +#define add_overflows(A, B) \ + __builtin_add_overflow_p((A), (B), (typeof((A) + (B)))0) +#else +#define add_overflows(A, B) ({ \ + typeof(A) a = (A); \ + typeof(B) b = (B); \ + a + b < a; \ +}) +#endif + #define range_overflows(start, size, max) ({ \ typeof(start) start__ = (start); \ typeof(size) size__ = (size); \ |