[PATCH v2 12/36] x86/elf/64: Clear more registers in elf_common_init

From: Andy Lutomirski
Date: Mon Oct 05 2015 - 20:56:53 EST


Before we start calling execve in contexts that honor the full
pt_regs, we need to teach it to initialize all registers.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/include/asm/elf.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 2ee05c4f5f37..1514753fd435 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -171,11 +171,11 @@ do { \
static inline void elf_common_init(struct thread_struct *t,
struct pt_regs *regs, const u16 ds)
{
- /* Commented-out registers are cleared in stub_execve */
- /*regs->ax = regs->bx =*/ regs->cx = regs->dx = 0;
- regs->si = regs->di /*= regs->bp*/ = 0;
+ /* ax gets execve's return value. */
+ /*regs->ax = */ regs->bx = regs->cx = regs->dx = 0;
+ regs->si = regs->di = regs->bp = 0;
regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
- /*regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;*/
+ regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
t->fs = t->gs = 0;
t->fsindex = t->gsindex = 0;
t->ds = t->es = ds;
--
2.4.3

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