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| author | Kees Cook <keescook@chromium.org> | 2020-03-27 07:48:18 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-04-20 19:41:50 +0200 |
| commit | 78066055b08096ed3282c027de9d9e137f9a1580 (patch) | |
| tree | f50e2231832938057a6d1203e8dacb5326281c9a /arch/arm64 | |
| parent | x86/elf: Disable automatic READ_IMPLIES_EXEC on 64-bit (diff) | |
| download | linux-78066055b08096ed3282c027de9d9e137f9a1580.tar.xz linux-78066055b08096ed3282c027de9d9e137f9a1580.zip | |
arm32/64/elf: Add tables to document READ_IMPLIES_EXEC
Add tables to document the current behavior of READ_IMPLIES_EXEC in
preparation for changing the behavior for both arm64 and arm.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lkml.kernel.org/r/20200327064820.12602-5-keescook@chromium.org
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/elf.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index b618017205a3..986ecf41fc0f 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -96,6 +96,26 @@ */ #define elf_check_arch(x) ((x)->e_machine == EM_AARCH64) +/* + * An executable for which elf_read_implies_exec() returns TRUE will + * have the READ_IMPLIES_EXEC personality flag set automatically. + * + * The decision process for determining the results are: + * + * CPU*: | arm32 | arm64 | + * ELF: | | | + * ---------------------|------------|------------| + * missing PT_GNU_STACK | exec-all | exec-all | + * PT_GNU_STACK == RWX | exec-all | exec-all | + * PT_GNU_STACK == RW | exec-none | exec-none | + * + * exec-all : all PROT_READ user mappings are executable, except when + * backed by files on a noexec-filesystem. + * exec-none : only PROT_EXEC user mappings are executable. + * + * *all arm64 CPUs support NX, so there is no "lacks NX" column. + * + */ #define elf_read_implies_exec(ex,stk) (stk != EXSTACK_DISABLE_X) #define CORE_DUMP_USE_REGSET |