PR #24748 opened by Pepe URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24748 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24748.patch
Fixes #24747 The dcbzl probe re-enables dcbzl even when it was disabled by `--disable-dcbzl` or by the e500/e500v2 `--cpu` cases, and e500 cores trap on it (SIGILL in `ff_blockdsp_init_ppc()` on a P2020). This runs the probe only when dcbzl is not disabled. It is Peter Krefting's 2022 fix (patchwork 38333) in the form @michaelni suggested there. Tested on a P2020 with master: the unpatched builds (`--cpu=8548 --disable-dcbzl` and `--cpu=e500v2`) crash, the patched ones contain no dcbzl and decode fine. configure output is unchanged for all other PowerPC `--cpu` values. Not changed here: `--cpu=8540` and `8548` still need `--disable-dcbzl`, generic ppc builds still enable dcbzl, and the ppc4xx probe has the same problem (#22698). cc @sean_mcg >From 65b8a2bad912c39e8fd63b772dc952e8bbd40f1b Mon Sep 17 00:00:00 2001 From: Josef Schlehofer <[email protected]> Date: Mon, 28 Sep 2026 07:56:27 +0200 Subject: [PATCH] configure: do not probe dcbzl when it is disabled The dcbzl probe runs unconditionally and re-enables dcbzl whenever the assembler accepts it, overriding --disable-dcbzl and the "disable dcbzl" in the e500 and e500v2 --cpu cases. e500 cores trap on dcbzl, so ffmpeg dies with SIGILL in ff_blockdsp_init_ppc() on a P2020 (e500v2) as soon as it opens an MPEG-2 decoder. Only run the probe when dcbzl is not disabled. Fixes: #24747 Suggested-by: Michael Niedermayer <[email protected]> Original-patch-by: Peter Krefting <[email protected]> Signed-off-by: Josef Schlehofer <[email protected]> --- configure | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/configure b/configure index 759cb8da10..5d8268fcfd 100755 --- a/configure +++ b/configure @@ -6662,7 +6662,7 @@ elif enabled parisc; then elif enabled ppc; then - check_inline_asm dcbzl '"dcbzl 0, %0" :: "r"(0)' + disabled dcbzl || check_inline_asm dcbzl '"dcbzl 0, %0" :: "r"(0)' check_inline_asm ibm_asm '"add 0, 0, 0"' check_inline_asm ppc4xx '"maclhw r10, r11, r12"' check_inline_asm xform_asm '"lwzx %1, %y0" :: "Z"(*(int*)0), "r"(0)' -- 2.52.0 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
