Le 16/08/2021 à 10:24, Joel Stanley a écrit :
When CONFIG_PPC_BARRIER_NOSPEC=n, security.c is not built leading to a
missing definition of uaccess_flush_key.
LD vmlinux.o
MODPOST vmlinux.symvers
MODINFO modules.builtin.modinfo
GEN modules.builtin
LD .tmp_vmlinux.kallsyms1
powerpc64le-linux-gnu-ld: arch/powerpc/kernel/align.o:(.toc+0x0): undefined
reference to `uaccess_flush_key'
powerpc64le-linux-gnu-ld: arch/powerpc/kernel/signal_64.o:(.toc+0x0): undefined
reference to `uaccess_flush_key'
powerpc64le-linux-gnu-ld: arch/powerpc/kernel/process.o:(.toc+0x0): undefined
reference to `uaccess_flush_key'
powerpc64le-linux-gnu-ld: arch/powerpc/kernel/traps.o:(.toc+0x0): undefined
reference to `uaccess_flush_key'
powerpc64le-linux-gnu-ld:
arch/powerpc/kernel/hw_breakpoint_constraints.o:(.toc+0x0): undefined reference
to `uaccess_flush_key'
powerpc64le-linux-gnu-ld: arch/powerpc/kernel/ptrace/ptrace.o:(.toc+0x0): more
undefined references to `uaccess_flush_key' follow
make[1]: *** [Makefile:1176: vmlinux] Error 1
Hack one in to fix the build.
Signed-off-by: Joel Stanley <j...@jms.id.au>
---
arch/powerpc/include/asm/security_features.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/include/asm/security_features.h
b/arch/powerpc/include/asm/security_features.h
index 792eefaf230b..46ade7927a4c 100644
--- a/arch/powerpc/include/asm/security_features.h
+++ b/arch/powerpc/include/asm/security_features.h
@@ -39,6 +39,9 @@ static inline bool security_ftr_enabled(u64 feature)
return !!(powerpc_security_features & feature);
}
+#ifndef CONFIG_PPC_BARRIER_NOSPEC
+DEFINE_STATIC_KEY_FALSE(uaccess_flush_key);
+#endif
It will then be re-defined by each file that includes asm/security_features.h
....
You can't use a DEFINE_ in a .h
You have to fix the problem at its source.
Cleanest way I see it to modify asm/book3s/64/kup.h and something like
if (IS_ENABLED(CONFIG_PPC_BARRIER_NOSPEC) &&
static_branch_unlikely(&uaccess_flush_key)
// Features indicating support for Spectre/Meltdown mitigations
