diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2025-05-04 11:52:43 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-05-04 15:59:43 +0200 |
| commit | f932adcc8650eb169efd0fd19f2a450c260d306c (patch) | |
| tree | c1b5649cc701fa074702dc32b9d3025e0226a9ae | |
| parent | ae862964cbc562582576da91b0b92742a574c437 (diff) | |
x86/linkage: Add SYM_PIC_ALIAS() macro helper to emit symbol aliases
Startup code that may execute from the early 1:1 mapping of memory will
be confined into its own address space, and only be permitted to access
ordinary kernel symbols if this is known to be safe.
Introduce a macro helper SYM_PIC_ALIAS() that emits a __pi_ prefixed
alias for a symbol, which allows startup code to access it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-38-ardb+git@google.com
| -rw-r--r-- | arch/x86/include/asm/linkage.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h index b51d8a4673f5..9d38ae744a2e 100644 --- a/arch/x86/include/asm/linkage.h +++ b/arch/x86/include/asm/linkage.h @@ -141,5 +141,15 @@ #define SYM_FUNC_START_WEAK_NOALIGN(name) \ SYM_START(name, SYM_L_WEAK, SYM_A_NONE) +/* + * Expose 'sym' to the startup code in arch/x86/boot/startup/, by emitting an + * alias prefixed with __pi_ + */ +#ifdef __ASSEMBLER__ +#define SYM_PIC_ALIAS(sym) SYM_ALIAS(__pi_ ## sym, sym, SYM_L_GLOBAL) +#else +#define SYM_PIC_ALIAS(sym) extern typeof(sym) __PASTE(__pi_, sym) __alias(sym) +#endif + #endif /* _ASM_X86_LINKAGE_H */ |