[PATCH x86/mm 1/6] x86-64 ia32 ptrace pt_regs cleanup

Roland McGrath
2007-11-29T00:39:13Z

This cleans up the getreg32/putreg32 functions to use struct pt_regs in a
straightforward fashion, instead of equivalent ugly pointer arithmetic.

Signed-off-by: Roland McGrath <roland@redhat.com>
---
arch/x86/ia32/ptrace32.c | 21 +++++++++------------
1 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/arch/x86/ia32/ptrace32.c b/arch/x86/ia32/ptrace32.c
index 1e382e3..c52d066 100644
--- a/arch/x86/ia32/ptrace32.c
+++ b/arch/x86/ia32/ptrace32.c
@@ -37,11 +37,11 @@

#define R32(l,q) \
case offsetof(struct user32, regs.l): \
- stack[offsetof(struct pt_regs, q) / 8] = val; break
+ regs->q = val; break;

static int putreg32(struct task_struct *child, unsigned regno, u32 val)
{
- __u64 *stack = (__u64 *)task_pt_regs(child);
+ struct pt_regs *regs = task_pt_regs(child);

switch (regno) {
case offsetof(struct user32, regs.fs):
@@ -65,12 +65,12 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)
case offsetof(struct user32, regs.ss):
if ((val & 3) != 3)
return -EIO;
- stack[offsetof(struct pt_regs, ss)/8] = val & 0xffff;
+ regs->ss = val & 0xffff;
break;
case offsetof(struct user32, regs.cs):
if ((val & 3) != 3)
return -EIO;
- stack[offsetof(struct pt_regs, cs)/8] = val & 0xffff;
+ regs->cs = val & 0xffff;
break;

R32(ebx, bx);
@@ -84,9 +84,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)
R32(eip, ip);
R32(esp, sp);

- case offsetof(struct user32, regs.eflags): {
- __u64 *flags = &stack[offsetof(struct pt_regs, flags)/8];
-
+ case offsetof(struct user32, regs.eflags):
val &= FLAG_MASK;
/*
* If the user value contains TF, mark that
@@ -97,9 +95,8 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)
clear_tsk_thread_flag(child, TIF_FORCED_TF);
else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
val |= X86_EFLAGS_TF;
- *flags = val | (*flags & ~FLAG_MASK);
+ regs->flags = val | (regs->flags & ~FLAG_MASK);
break;
- }

case offsetof(struct user32, u_debugreg[0]) ...
offsetof(struct user32, u_debugreg[7]):
@@ -123,11 +120,11 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)

#define R32(l,q) \
case offsetof(struct user32, regs.l): \
- *val = stack[offsetof(struct pt_regs, q)/8]; break
+ *val = regs->q; break

static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
{
- __u64 *stack = (__u64 *)task_pt_regs(child);
+ struct pt_regs *regs = task_pt_regs(child);

switch (regno) {
case offsetof(struct user32, regs.fs):
@@ -160,7 +157,7 @@ static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
/*
* If the debugger set TF, hide it from the readout.
*/
- *val = stack[offsetof(struct pt_regs, flags)/8];
+ *val = regs->flags;
if (test_tsk_thread_flag(child, TIF_FORCED_TF))
*val &= ~X86_EFLAGS_TF;
break;