From 9dde6ab06c48f9447cd16f39bee33569cddb7be4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Storsj=C3=B6?= Date: Thu, 31 Aug 2017 12:06:44 +0300 Subject: [PATCH] arm: Fix SIGBUS on ARM when compiled with binutils 2.29 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In binutils 2.29, the behavior of the ADR instruction changed so that 1 is added to the address of a Thumb function (previously nothing was added). This allows the loaded address to be passed to a BLX instruction and the correct mode change will occur. See: https://sourceware.org/bugzilla/show_bug.cgi?id=21458 By using adr with a label that isn't annotated as a thumb function, we avoid the new behaviour in binutils 2.29 and get the same behaviour as in prior releases, and as in other assemblers (ms armasm.exe, clang's built in assembler) - an idea that Janne Grunau came up with. Signed-off-by: Martin Storsjö --- libavcodec/arm/h264idct_neon.S | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/libavcodec/arm/h264idct_neon.S b/libavcodec/arm/h264idct_neon.S index f588f3e744..b078cf25f9 100644 --- a/libavcodec/arm/h264idct_neon.S +++ b/libavcodec/arm/h264idct_neon.S @@ -21,6 +21,7 @@ #include "libavutil/arm/asm.S" function ff_h264_idct_add_neon, export=1 +h264_idct_add_neon_nothumb: vld1.64 {d0-d3}, [r1,:128] vmov.i16 q15, #0 @@ -73,6 +74,7 @@ function ff_h264_idct_add_neon, export=1 endfunc function ff_h264_idct_dc_add_neon, export=1 +h264_idct_dc_add_neon_nothumb: mov r3, #0 vld1.16 {d2[],d3[]}, [r1,:16] strh r3, [r1] @@ -113,8 +115,8 @@ function ff_h264_idct_add16_neon, export=1 movne lr, #0 cmp lr, #0 ite ne - adrne lr, X(ff_h264_idct_dc_add_neon) + CONFIG_THUMB - adreq lr, X(ff_h264_idct_add_neon) + CONFIG_THUMB + adrne lr, h264_idct_dc_add_neon_nothumb + CONFIG_THUMB + adreq lr, h264_idct_add_neon_nothumb + CONFIG_THUMB blx lr 2: subs ip, ip, #1 add r1, r1, #32 @@ -138,8 +140,8 @@ function ff_h264_idct_add16intra_neon, export=1 cmp r8, #0 ldrsh r8, [r1] iteet ne - adrne lr, X(ff_h264_idct_add_neon) + CONFIG_THUMB - adreq lr, X(ff_h264_idct_dc_add_neon) + CONFIG_THUMB + adrne lr, h264_idct_add_neon_nothumb + CONFIG_THUMB + adreq lr, h264_idct_dc_add_neon_nothumb + CONFIG_THUMB cmpeq r8, #0 blxne lr subs ip, ip, #1 @@ -166,8 +168,8 @@ function ff_h264_idct_add8_neon, export=1 cmp r8, #0 ldrsh r8, [r1] iteet ne - adrne lr, X(ff_h264_idct_add_neon) + CONFIG_THUMB - adreq lr, X(ff_h264_idct_dc_add_neon) + CONFIG_THUMB + adrne lr, h264_idct_add_neon_nothumb + CONFIG_THUMB + adreq lr, h264_idct_dc_add_neon_nothumb + CONFIG_THUMB cmpeq r8, #0 blxne lr add r12, r12, #1 @@ -267,6 +269,7 @@ endfunc .endm function ff_h264_idct8_add_neon, export=1 +h264_idct8_add_neon_nothumb: vmov.i16 q3, #0 vld1.16 {q8-q9}, [r1,:128] vst1.16 {q3}, [r1,:128]! @@ -328,6 +331,7 @@ function ff_h264_idct8_add_neon, export=1 endfunc function ff_h264_idct8_dc_add_neon, export=1 +h264_idct8_dc_add_neon_nothumb: mov r3, #0 vld1.16 {d30[],d31[]},[r1,:16] strh r3, [r1] @@ -388,8 +392,8 @@ function ff_h264_idct8_add4_neon, export=1 movne lr, #0 cmp lr, #0 ite ne - adrne lr, X(ff_h264_idct8_dc_add_neon) + CONFIG_THUMB - adreq lr, X(ff_h264_idct8_add_neon) + CONFIG_THUMB + adrne lr, h264_idct8_dc_add_neon_nothumb + CONFIG_THUMB + adreq lr, h264_idct8_add_neon_nothumb + CONFIG_THUMB blx lr 2: subs r12, r12, #4 add r1, r1, #128 -- 2.13.6