From 1b03cf7adc3c156ecab2618acb1ec585336a3f75 Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Tue, 29 Mar 2022 18:12:28 +0800 Subject: purgatory: do not enable vectorization automatically for purgatory compiling Redhat CKI reported kdump kernel will hang a while very early after crash triggered, then reset to firmware to reboot. This failure can only be observed with kdump or kexec reboot via kexec_load system call. With kexec_file_load interface, both kdump and kexec reboot work very well. And further investigation shows that gcc version 11 doesn't have this issue, while gcc version 12 does. After checking the release notes of the latest gcc, Dave found out it's because gcc 12 enables auto-vectorization for -O2 optimization level. Please see below link for more information: https://www.phoronix.com/scan.php?page=news_item&px=GCC-12-Auto-Vec-O2 Adding -fno-tree-vectorize to Makefile of purgatory can fix the issue. Signed-off-by: Baoquan He Signed-off-by: Simon Horman --- purgatory/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/purgatory/Makefile b/purgatory/Makefile index 2dd6c476..15adb120 100644 --- a/purgatory/Makefile +++ b/purgatory/Makefile @@ -49,7 +49,7 @@ $(PURGATORY): CFLAGS=$(PURGATORY_EXTRA_CFLAGS) \ $($(ARCH)_PURGATORY_EXTRA_CFLAGS) \ -Os -fno-builtin -ffreestanding \ -fno-zero-initialized-in-bss \ - -fno-PIC -fno-PIE -fno-stack-protector + -fno-PIC -fno-PIE -fno-stack-protector -fno-tree-vectorize $(PURGATORY): CPPFLAGS=$($(ARCH)_PURGATORY_EXTRA_CFLAGS) \ -I$(srcdir)/purgatory/include \ -- cgit 1.2.3-korg