Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965196AbcKDRdk (ORCPT ); Fri, 4 Nov 2016 13:33:40 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:63824 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934992AbcKDRdj (ORCPT ); Fri, 4 Nov 2016 13:33:39 -0400 From: Eric Engestrom To: CC: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Rob Clark , Eric Engestrom , David Airlie , Subject: [PATCH variant 1] drm: make drm_get_format_name atomic/irq safe again Date: Fri, 4 Nov 2016 17:33:22 +0000 Message-ID: <20161104173322.20594-1-eric.engestrom@imgtec.com> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161104173224.GJ25290@imgtec.com> References: <20161104173224.GJ25290@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.60.4.28] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1851 Lines: 56 Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07 drm: make drm_get_format_name thread-safe Signed-off-by: Eric Engestrom [danvet: Clarify that the returned pointer must be freed with kfree().] Signed-off-by: Daniel Vetter Note (Rob Clark): I think we need to be a bit careful about follow-up audits of callers of this.. now that you need to kfree the return value I think it is fairly easy for new patches to introduce new callers which leak the return value. We probably should have left the function as-is and introduce a new variant, or something like that. Suggested-by: Rob Clark (GFP_ATOMIC) Suggested-by: Ville Syrjälä (kasprintf) Signed-off-by: Eric Engestrom --- I'll send another variant tonight that moves the allocation to the callers (sounds cleaner to me, although there'll be some code duplication and more opportunities to make mistakes I guess). --- drivers/gpu/drm/drm_fourcc.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c index 29c56b4..66dcf21 100644 --- a/drivers/gpu/drm/drm_fourcc.c +++ b/drivers/gpu/drm/drm_fourcc.c @@ -87,9 +87,7 @@ EXPORT_SYMBOL(drm_mode_legacy_fb_format); */ char *drm_get_format_name(uint32_t format) { - char *buf = kmalloc(32, GFP_KERNEL); - - snprintf(buf, 32, + return kasprintf(GFP_ATOMIC, "%c%c%c%c %s-endian (0x%08x)", printable_char(format & 0xff), printable_char((format >> 8) & 0xff), @@ -97,8 +95,6 @@ char *drm_get_format_name(uint32_t format) printable_char((format >> 24) & 0x7f), format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little", format); - - return buf; } EXPORT_SYMBOL(drm_get_format_name); -- Cheers, Eric