On Tue, Jun 16, 2020 at 10:11:46PM +0200, Gabriel C wrote: > * Am So., 14. Juni 2020 um 22:44 Uhr schrieb Linus Torvalds > <torva...@linux-foundation.org>: > > Hello, > > > So I didn't really expect this, but 5.8 looks to be one of our biggest > > releases of all time. > > > > I hit a compiler error caused by e4160b2e4b02377c67f8ecd05786811598f39acd. > > x86/purgatory: Fail the build if purgatory.ro has missing symbols > > Having CONFIG_STACKPROTECTOR* & CONFIG_KEXEC_FILE enabled always > results in a linking error like this: > > LD arch/x86/purgatory/purgatory.chk > ld: arch/x86/purgatory/purgatory.ro: in function `verify_sha256_digest': > purgatory.c:(.text+0x108): undefined reference to `__stack_chk_fail' > ld: arch/x86/purgatory/purgatory.ro: in function `sha256_transform': > sha256.c:(.text+0x1c74): undefined reference to `__stack_chk_fail' > ld: arch/x86/purgatory/purgatory.ro: in function `__sha256_final': > sha256.c:(.text+0x1e65): undefined reference to `__stack_chk_fail' > ld: arch/x86/purgatory/purgatory.ro: in function `_kstrtoull': > string.c:(.text+0x2107): undefined reference to `__stack_chk_fail' > > I didn't look closer at that but from the error, it seems to be, > some missing -fstack-protector* vs -fno-stack-protector* checks > somewhere. > > > Best Regards, > > Gabriel C
Can you attach the output of gcc -dumpspecs and gcc -v? I suspect your compiler enables stack protector by default. My distro compiler does that too, but not if -ffreestanding is enabled (which it is for the purgatory). Does this patch help? diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index b04e6e72a592..088bd764e0b7 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -34,6 +34,7 @@ KCOV_INSTRUMENT := n PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING +PURGATORY_CFLAGS += $(call cc-option,-fno-stack-protector) # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That # in turn leaves some undefined symbols like __fentry__ in purgatory and not
