| Message ID | 1379668859-21238-1-git-send-email-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Sep 20, 2013 at 10:20:59AM +0100, Chris Wilson wrote: > In > > commit edc3d8848dc9fe2a470316363dab8ef211d77e01 > Author: Mika Kuoppala <mika.kuoppala@linux.intel.com> > Date: Thu May 23 13:55:35 2013 +0300 > > drm/i915: avoid big kmallocs on reading error state > > we introduce a two-pass mechanism for splitting long strings being > formatted into the error-state. The first pass finds the length, and the > second pass emits the right portion of the string into the accumulation > buffer. Unfortunately we use the same va_list for both passes, resulting > in the second pass reading garbage off the end of the argument list. As > the two passes are only used for boundaries between read() calls, the > corruption is only rarely seen. > > This fixes the root cause behind > > commit baf27f9b17bf2f369f3865e38c41d2163e8d815d > Author: Chris Wilson <chris@chris-wilson.co.uk> > Date: Sat Jun 29 23:26:50 2013 +0100 > > drm/i915: Break up the large vsnprintf() in print_error_buffers() > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Mika Kuoppala <mika.kuoppala@intel.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: stable@vger.kernel.org Picked up for -fixes, thanks for the patch. -Daniel
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index c38d575..7bea613 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -143,8 +143,10 @@ static void i915_error_vprintf(struct drm_i915_error_state_buf *e, /* Seek the first printf which is hits start position */ if (e->pos < e->start) { - len = vsnprintf(NULL, 0, f, args); - if (!__i915_error_seek(e, len)) + va_list tmp; + + va_copy(tmp, args); + if (!__i915_error_seek(e, vsnprintf(NULL, 0, f, tmp))) return; }
In commit edc3d8848dc9fe2a470316363dab8ef211d77e01 Author: Mika Kuoppala <mika.kuoppala@linux.intel.com> Date: Thu May 23 13:55:35 2013 +0300 drm/i915: avoid big kmallocs on reading error state we introduce a two-pass mechanism for splitting long strings being formatted into the error-state. The first pass finds the length, and the second pass emits the right portion of the string into the accumulation buffer. Unfortunately we use the same va_list for both passes, resulting in the second pass reading garbage off the end of the argument list. As the two passes are only used for boundaries between read() calls, the corruption is only rarely seen. This fixes the root cause behind commit baf27f9b17bf2f369f3865e38c41d2163e8d815d Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Sat Jun 29 23:26:50 2013 +0100 drm/i915: Break up the large vsnprintf() in print_error_buffers() Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/i915_gpu_error.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)