x86: ptrace: do not sign-extend orig_ax on write (08ff18e2) · Commits · 戴 / test

arch/x86/kernel/ptrace.c

+1 −18

Original line number	Diff line number	Diff line
		@@ -325,16 +325,6 @@ static int putreg(struct task_struct *child,
		return set_flags(child, value);

		#ifdef CONFIG_X86_64
		/*
		* Orig_ax is really just a flag with small positive and
		* negative values, so make sure to always sign-extend it
		* from 32 bits so that it works correctly regardless of
		* whether we come from a 32-bit environment or not.
		*/
		case offsetof(struct user_regs_struct, orig_ax):
		value = (long) (s32) value;
		break;

		case offsetof(struct user_regs_struct,fs_base):
		if (value >= TASK_SIZE_OF(child))
		return -EIO;
		@@ -1121,17 +1111,10 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
		R32(esi, si);
		R32(ebp, bp);
		R32(eax, ax);
		R32(orig_eax, orig_ax);
		R32(eip, ip);
		R32(esp, sp);

		case offsetof(struct user32, regs.orig_eax):
		/*
		* Sign-extend the value so that orig_eax = -1
		* causes (long)orig_ax < 0 tests to fire correctly.
		*/
		regs->orig_ax = (long) (s32) value;
		break;

		case offsetof(struct user32, regs.eflags):
		return set_flags(child, value);