diff options
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/x86/c_start.S | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/arch/x86/c_start.S b/src/arch/x86/c_start.S index 02ddf75d12..6bea8db10d 100644 --- a/src/arch/x86/c_start.S +++ b/src/arch/x86/c_start.S @@ -59,6 +59,24 @@ _start: leal _stack, %edi #endif +#if ENV_X86_64 + /** poison the stack. Code should not count on the + * stack being full of zeros. This stack poisoning + * recently uncovered a bug in the broadcast SIPI + * code. + */ + movabs $_estack, %rcx + sub %rdi, %rcx + shr $3, %rcx /* it is 64 bit aligned, right? */ + movq $0xDEADBEEFDEADBEEF, %rax + rep + stosq + + /* Set new stack with enforced alignment. */ + movabs $_estack, %rsp + movq $(0xfffffffffffffff0), %rax + and %rax, %rsp +#else /** poison the stack. Code should not count on the * stack being full of zeros. This stack poisoning * recently uncovered a bug in the broadcast SIPI @@ -74,6 +92,7 @@ _start: /* Set new stack with enforced alignment. */ movl $_estack, %esp andl $(0xfffffff0), %esp +#endif /* * Now we are finished. Memory is up, data is copied and @@ -82,7 +101,12 @@ _start: */ post_code(POSTCODE_PRE_HARDWAREMAIN) /* post 6e */ +#if ENV_X86_64 + movq $0xFFFFFFFFFFFFFFF0, %rax + and %rax, %rsp +#else andl $0xFFFFFFF0, %esp +#endif #if CONFIG(ASAN_IN_RAMSTAGE) call asan_init |