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authorMickaël Salaün <mic@digikod.net>2015-12-29 23:35:44 +0300
committerRichard Weinberger <richard@nod.at>2016-01-10 23:49:48 +0300
commite04c989eb785af61d2895d76d38c09166296f9c5 (patch)
treea4698bceed0851ec151539c275e5d615da506d36 /arch/x86/um
parenta7df4716d19594b7b3f106f0bc0ca1c548e508e6 (diff)
downloadlinux-e04c989eb785af61d2895d76d38c09166296f9c5.tar.xz
um: Fix ptrace GETREGS/SETREGS bugs
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 <mic@digikod.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Thomas Meyer <thomas@m3y3r.de> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Anton Ivanov <aivanov@brocade.com> Cc: Meredydd Luff <meredydd@senatehouse.org> Cc: David Drysdale <drysdale@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'arch/x86/um')
-rw-r--r--arch/x86/um/ptrace_32.c8
1 files changed, 3 insertions, 5 deletions
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);