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| author | Michael Ellerman <mpe@ellerman.id.au> | 2022-07-18 15:44:18 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-07-20 07:13:02 +0200 |
| commit | be640317a1d0b9cf42fedb2debc2887a7cfa38de (patch) | |
| tree | 555542ae4769b6fb0dee72111cc950e4cdf15c31 /arch/powerpc/kernel/Makefile | |
| parent | powerpc/powernv: delay rng platform device creation until later in boot (diff) | |
| download | linux-be640317a1d0b9cf42fedb2debc2887a7cfa38de.tar.xz linux-be640317a1d0b9cf42fedb2debc2887a7cfa38de.zip | |
powerpc/64s: Disable stack variable initialisation for prom_init
With GCC 12 allmodconfig prom_init fails to build:
Error: External symbol 'memset' referenced from prom_init.c
make[2]: *** [arch/powerpc/kernel/Makefile:204: arch/powerpc/kernel/prom_init_check] Error 1
The allmodconfig build enables KASAN, so all calls to memset in
prom_init should be converted to __memset by the #ifdefs in
asm/string.h, because prom_init must use the non-KASAN instrumented
versions.
The build failure happens because there's a call to memset that hasn't
been caught by the pre-processor and converted to __memset. Typically
that's because it's a memset generated by the compiler itself, and that
is the case here.
With GCC 12, allmodconfig enables CONFIG_INIT_STACK_ALL_PATTERN, which
causes the compiler to emit memset calls to initialise on-stack
variables with a pattern.
Because prom_init is non-user-facing boot-time only code, as a
workaround just disable stack variable initialisation to unbreak the
build.
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220718134418.354114-1-mpe@ellerman.id.au
Diffstat (limited to 'arch/powerpc/kernel/Makefile')
| -rw-r--r-- | arch/powerpc/kernel/Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index f91f0f29a566..c8cf924bf9c0 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -20,6 +20,7 @@ CFLAGS_prom.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) CFLAGS_prom_init.o += -fno-stack-protector CFLAGS_prom_init.o += -DDISABLE_BRANCH_PROFILING CFLAGS_prom_init.o += -ffreestanding +CFLAGS_prom_init.o += $(call cc-option, -ftrivial-auto-var-init=uninitialized) ifdef CONFIG_FUNCTION_TRACER # Do not trace early boot code |