From: Kees Cook <keescook@xxxxxxxxxxxx> Subject: sh/boot: add static stack-protector to pre-kernel The sh decompressor code triggers stack-protector code generation when using CONFIG_CC_STACKPROTECTOR_STRONG. As done for arm and mips, add a simple static stack-protector canary. As this wasn't protected before, the risk of using a weak canary is minimized. Once the kernel is actually up, a better canary is chosen. Link: http://lkml.kernel.org/r/1506972007-80614-2-git-send-email-keescook@xxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> Cc: Rich Felker <dalias@xxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Laura Abbott <labbott@xxxxxxxxxx> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Cc: Michal Marek <mmarek@xxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/sh/boot/compressed/misc.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff -puN arch/sh/boot/compressed/misc.c~sh-boot-add-static-stack-protector-to-pre-kernel arch/sh/boot/compressed/misc.c --- a/arch/sh/boot/compressed/misc.c~sh-boot-add-static-stack-protector-to-pre-kernel +++ a/arch/sh/boot/compressed/misc.c @@ -104,6 +104,18 @@ static void error(char *x) while(1); /* Halt */ } +unsigned long __stack_chk_guard; + +void __stack_chk_guard_setup(void) +{ + __stack_chk_guard = 0x000a0dff; +} + +void __stack_chk_fail(void) +{ + error("stack-protector: Kernel stack is corrupted\n"); +} + #ifdef CONFIG_SUPERH64 #define stackalign 8 #else @@ -118,6 +130,8 @@ void decompress_kernel(void) { unsigned long output_addr; + __stack_chk_guard_setup(); + #ifdef CONFIG_SUPERH64 output_addr = (CONFIG_MEMORY_START + 0x2000); #else _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
