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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2007-06-04 15:15:46 +1000
committerPaul Mackerras <paulus@samba.org>2007-06-14 22:29:57 +1000
commit912000e73ee8fcb97831b123c9c3a7274b71cab7 (patch)
treea81fcda0f11cbb4c428ffae9f9f55f12677051fe
parent1b6610d6fcb8dc23631cf48f09aa02e6649e379d (diff)
[POWERPC] Allow ptrace write to pt_regs trap and orig_r3
This patch allows a ptracer to write to the "trap" and "orig_r3" words of the pt_regs. This, along with a subsequent patch to the signal restart code, should enable gdb to properly handle syscall restarting after executing a separate function (at least when there's no restart block). This patch also removes ptrace32.c code toying directly with the registers and makes it use the ptrace_get/put_reg() accessors for everything so that the logic for checking what is permitted is in only one place. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--arch/powerpc/kernel/ptrace.c9
-rw-r--r--arch/powerpc/kernel/ptrace32.c27
2 files changed, 20 insertions, 16 deletions
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index c9c330d35c1..dd4837c4a68 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -75,10 +75,15 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
if (task->thread.regs == NULL)
return -EIO;
- if (regno <= PT_MAX_PUT_REG) {
+ if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) {
if (regno == PT_MSR)
data = (data & MSR_DEBUGCHANGE)
| (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
+ /* We prevent mucking around with the reserved area of trap
+ * which are used internally by the kernel
+ */
+ if (regno == PT_TRAP)
+ data &= 0xfff0;
((unsigned long *)task->thread.regs)[regno] = data;
return 0;
}
@@ -409,8 +414,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
break;
CHECK_FULL_REGS(child->thread.regs);
- if (index == PT_ORIG_R3)
- break;
if (index < PT_FPR0) {
ret = ptrace_put_reg(child, index, data);
} else {
diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c
index 4511b422992..aae6a988e18 100644
--- a/arch/powerpc/kernel/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace32.c
@@ -206,7 +206,9 @@ long compat_sys_ptrace(int request, int pid, unsigned long addr,
else
part = 0; /* want the 1st half of the register (left-most). */
- /* Validate the input - check to see if address is on the wrong boundary or beyond the end of the user area */
+ /* Validate the input - check to see if address is on the wrong boundary
+ * or beyond the end of the user area
+ */
if ((addr & 3) || numReg > PT_FPSCR)
break;
@@ -270,8 +272,6 @@ long compat_sys_ptrace(int request, int pid, unsigned long addr,
if ((addr & 3) || (index > PT_FPSCR32))
break;
- if (index == PT_ORIG_R3)
- break;
if (index < PT_FPR0) {
ret = ptrace_put_reg(child, index, data);
} else {
@@ -302,24 +302,25 @@ long compat_sys_ptrace(int request, int pid, unsigned long addr,
/* Determine which register the user wants */
index = (u64)addr >> 2;
numReg = index / 2;
+
/*
* Validate the input - check to see if address is on the
* wrong boundary or beyond the end of the user area
*/
if ((addr & 3) || (numReg > PT_FPSCR))
break;
- /* Insure it is a register we let them change */
- if ((numReg == PT_ORIG_R3)
- || ((numReg > PT_CCR) && (numReg < PT_FPR0)))
- break;
- if (numReg >= PT_FPR0) {
+ if (numReg < PT_FPR0) {
+ unsigned long freg = ptrace_get_reg(child, numReg);
+ if (index % 2)
+ freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
+ else
+ freg = (freg & 0xfffffffful) | (data << 32);
+ ret = ptrace_put_reg(child, numReg, freg);
+ } else {
flush_fp_to_thread(child);
+ ((unsigned int *)child->thread.regs)[index] = data;
+ ret = 0;
}
- if (numReg == PT_MSR)
- data = (data & MSR_DEBUGCHANGE)
- | (child->thread.regs->msr & ~MSR_DEBUGCHANGE);
- ((u32*)child->thread.regs)[index] = data;
- ret = 0;
break;
}