The patch below does not apply to the 3.11-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From e29bb4ebbf000ff9ac081d29784a3331618f012e Mon Sep 17 00:00:00 2001 From: Chris Wilson <[email protected]> Date: Fri, 20 Sep 2013 10:20:59 +0100 Subject: [PATCH] drm/i915: Use a temporary va_list for two-pass string handling In commit edc3d8848dc9fe2a470316363dab8ef211d77e01 Author: Mika Kuoppala <[email protected]> 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 <[email protected]> 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 <[email protected]> Cc: Mika Kuoppala <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: [email protected] Signed-off-by: Daniel Vetter <[email protected]> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index aba9d74..dae364f 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; } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
