From e04c989eb785af61d2895d76d38c09166296f9c5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Tue, 29 Dec 2015 21:35:44 +0100 Subject: um: Fix ptrace GETREGS/SETREGS bugs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This fix two related bugs: * PTRACE_GETREGS doesn't get the right orig_ax (syscall) value * PTRACE_SETREGS can't set the orig_ax value (erased by initial value) Get rid of the now useless and error-prone get_syscall(). Fix inconsistent behavior in the ptrace implementation for i386 when updating orig_eax automatically update the syscall number as well. This is now updated in handle_syscall(). Signed-off-by: Mickaël Salaün Cc: Jeff Dike Cc: Richard Weinberger Cc: Thomas Gleixner Cc: Kees Cook Cc: Andy Lutomirski Cc: Will Drewry Cc: Thomas Meyer Cc: Nicolas Iooss Cc: Anton Ivanov Cc: Meredydd Luff Cc: David Drysdale Signed-off-by: Richard Weinberger Acked-by: Kees Cook --- arch/x86/um/ptrace_32.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'arch/x86/um/ptrace_32.c') diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c index a29756f2d940..47c78d5e5c32 100644 --- a/arch/x86/um/ptrace_32.c +++ b/arch/x86/um/ptrace_32.c @@ -68,6 +68,7 @@ static const int reg_offsets[] = { [EFL] = HOST_EFLAGS, [UESP] = HOST_SP, [SS] = HOST_SS, + [ORIG_EAX] = HOST_ORIG_AX, }; int putreg(struct task_struct *child, int regno, unsigned long value) @@ -83,6 +84,7 @@ int putreg(struct task_struct *child, int regno, unsigned long value) case EAX: case EIP: case UESP: + case ORIG_EAX: break; case FS: if (value && (value & 3) != 3) @@ -108,9 +110,6 @@ int putreg(struct task_struct *child, int regno, unsigned long value) value &= FLAG_MASK; child->thread.regs.regs.gp[HOST_EFLAGS] |= value; return 0; - case ORIG_EAX: - child->thread.regs.regs.syscall = value; - return 0; default : panic("Bad register in putreg() : %d\n", regno); } @@ -143,8 +142,6 @@ unsigned long getreg(struct task_struct *child, int regno) regno >>= 2; switch (regno) { - case ORIG_EAX: - return child->thread.regs.regs.syscall; case FS: case GS: case DS: @@ -163,6 +160,7 @@ unsigned long getreg(struct task_struct *child, int regno) case EDI: case EBP: case EFL: + case ORIG_EAX: break; default: panic("Bad register in getreg() : %d\n", regno); -- cgit v1.2.3