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authorChris Metcalf <cmetcalf@tilera.com>2010-10-14 16:48:00 -0400
committerChris Metcalf <cmetcalf@tilera.com>2010-10-15 15:39:44 -0400
commitce7f2a39675ea5e8e27b3f3bb03e5041c7d10412 (patch)
tree5552e14b279cac5acc56c2b9cd3114d8e612a078 /arch/tile/kernel/ptrace.c
parentc569cac8b69397d8bc80f95bc6edf13ed902e28b (diff)
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arch/tile: make ptrace() work properly for TILE-Gx COMPAT mode
Previously, we tried to pass 64-bit arguments through the "COMPAT" mode 32-bit syscall API, which turned out not to work well. Now we just use straight 32-bit arguments in COMPAT mode, thus requiring individual registers to be read/written with two syscalls. Of course this is uncommon, since usually all the registers are read or written at once. The restructuring applies to all the tile platforms, but is plausibly better than the original code in any case. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/kernel/ptrace.c')
-rw-r--r--arch/tile/kernel/ptrace.c78
1 files changed, 36 insertions, 42 deletions
diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
index 7161bd03d2f..5b20c2874d5 100644
--- a/arch/tile/kernel/ptrace.c
+++ b/arch/tile/kernel/ptrace.c
@@ -32,25 +32,6 @@ void user_disable_single_step(struct task_struct *child)
}
/*
- * This routine will put a word on the process's privileged stack.
- */
-static void putreg(struct task_struct *task,
- unsigned long addr, unsigned long value)
-{
- unsigned int regno = addr / sizeof(unsigned long);
- struct pt_regs *childregs = task_pt_regs(task);
- childregs->regs[regno] = value;
- childregs->flags |= PT_FLAGS_RESTORE_REGS;
-}
-
-static unsigned long getreg(struct task_struct *task, unsigned long addr)
-{
- unsigned int regno = addr / sizeof(unsigned long);
- struct pt_regs *childregs = task_pt_regs(task);
- return childregs->regs[regno];
-}
-
-/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
@@ -66,59 +47,72 @@ void ptrace_disable(struct task_struct *child)
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
- unsigned long __user *datap;
+ unsigned long __user *datap = (long __user __force *)data;
unsigned long tmp;
int i;
long ret = -EIO;
-
-#ifdef CONFIG_COMPAT
- if (task_thread_info(current)->status & TS_COMPAT)
- data = (u32)data;
- if (task_thread_info(child)->status & TS_COMPAT)
- addr = (u32)addr;
-#endif
- datap = (unsigned long __user __force *)data;
+ unsigned long *childregs;
+ char *childreg;
switch (request) {
case PTRACE_PEEKUSR: /* Read register from pt_regs. */
- if (addr & (sizeof(data)-1))
- break;
if (addr < 0 || addr >= PTREGS_SIZE)
break;
- tmp = getreg(child, addr); /* Read register */
- ret = put_user(tmp, datap);
+ childreg = (char *)task_pt_regs(child) + addr;
+#ifdef CONFIG_COMPAT
+ if (is_compat_task()) {
+ if (addr & (sizeof(compat_long_t)-1))
+ break;
+ ret = put_user(*(compat_long_t *)childreg,
+ (compat_long_t __user *)datap);
+ } else
+#endif
+ {
+ if (addr & (sizeof(long)-1))
+ break;
+ ret = put_user(*(long *)childreg, datap);
+ }
break;
case PTRACE_POKEUSR: /* Write register in pt_regs. */
- if (addr & (sizeof(data)-1))
- break;
if (addr < 0 || addr >= PTREGS_SIZE)
break;
- putreg(child, addr, data); /* Write register */
+ childreg = (char *)task_pt_regs(child) + addr;
+#ifdef CONFIG_COMPAT
+ if (is_compat_task()) {
+ if (addr & (sizeof(compat_long_t)-1))
+ break;
+ *(compat_long_t *)childreg = data;
+ } else
+#endif
+ {
+ if (addr & (sizeof(long)-1))
+ break;
+ *(long *)childreg = data;
+ }
ret = 0;
break;
case PTRACE_GETREGS: /* Get all registers from the child. */
if (!access_ok(VERIFY_WRITE, datap, PTREGS_SIZE))
break;
- for (i = 0; i < PTREGS_SIZE; i += sizeof(long)) {
- ret = __put_user(getreg(child, i), datap);
+ childregs = (long *)task_pt_regs(child);
+ for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i) {
+ ret = __put_user(childregs[i], &datap[i]);
if (ret != 0)
break;
- datap++;
}
break;
case PTRACE_SETREGS: /* Set all registers in the child. */
if (!access_ok(VERIFY_READ, datap, PTREGS_SIZE))
break;
- for (i = 0; i < PTREGS_SIZE; i += sizeof(long)) {
- ret = __get_user(tmp, datap);
+ childregs = (long *)task_pt_regs(child);
+ for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i) {
+ ret = __get_user(childregs[i], &datap[i]);
if (ret != 0)
break;
- putreg(child, i, tmp);
- datap++;
}
break;