From ee4a3916614829914830bc4371358f4d4a63c4d9 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Thu, 14 Feb 2013 17:44:23 +0000 Subject: [PATCH] powerpc: fixing ptrace_get_reg to return an error Currently ptrace_get_reg returns error as a value what make impossible to tell whether it is a correct value or error code. The patch adds a parameter which points to the real return data and returns an error code. As get_user_msr() never fails and it is used in multiple places so it has not been changed by this patch. Signed-off-by: Alexey Kardashevskiy Acked-by: Michael Neuling Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/ptrace.h | 3 ++- arch/powerpc/kernel/ptrace.c | 29 ++++++++++++++++++----------- arch/powerpc/kernel/ptrace32.c | 15 ++++++++++++--- 3 files changed, 32 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index 5f99568..becc08e 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -92,7 +92,8 @@ static inline long regs_return_value(struct pt_regs *regs) } while(0) struct task_struct; -extern unsigned long ptrace_get_reg(struct task_struct *task, int regno); +extern int ptrace_get_reg(struct task_struct *task, int regno, + unsigned long *data); extern int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data); diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index f9b30c6..10ade3c 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -180,9 +180,10 @@ static int set_user_msr(struct task_struct *task, unsigned long msr) } #ifdef CONFIG_PPC64 -static unsigned long get_user_dscr(struct task_struct *task) +static int get_user_dscr(struct task_struct *task, unsigned long *data) { - return task->thread.dscr; + *data = task->thread.dscr; + return 0; } static int set_user_dscr(struct task_struct *task, unsigned long dscr) @@ -192,7 +193,7 @@ static int set_user_dscr(struct task_struct *task, unsigned long dscr) return 0; } #else -static unsigned long get_user_dscr(struct task_struct *task) +static int get_user_dscr(struct task_struct *task, unsigned long *data) { return -EIO; } @@ -216,19 +217,23 @@ static int set_user_trap(struct task_struct *task, unsigned long trap) /* * Get contents of register REGNO in task TASK. */ -unsigned long ptrace_get_reg(struct task_struct *task, int regno) +int ptrace_get_reg(struct task_struct *task, int regno, unsigned long *data) { - if (task->thread.regs == NULL) + if ((task->thread.regs == NULL) || !data) return -EIO; - if (regno == PT_MSR) - return get_user_msr(task); + if (regno == PT_MSR) { + *data = get_user_msr(task); + return 0; + } if (regno == PT_DSCR) - return get_user_dscr(task); + return get_user_dscr(task, data); - if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) - return ((unsigned long *)task->thread.regs)[regno]; + if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) { + *data = ((unsigned long *)task->thread.regs)[regno]; + return 0; + } return -EIO; } @@ -1560,7 +1565,9 @@ long arch_ptrace(struct task_struct *child, long request, CHECK_FULL_REGS(child->thread.regs); if (index < PT_FPR0) { - tmp = ptrace_get_reg(child, (int) index); + ret = ptrace_get_reg(child, (int) index, &tmp); + if (ret) + break; } else { unsigned int fpidx = index - PT_FPR0; diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c index c0244e7..f51599e 100644 --- a/arch/powerpc/kernel/ptrace32.c +++ b/arch/powerpc/kernel/ptrace32.c @@ -95,7 +95,9 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, CHECK_FULL_REGS(child->thread.regs); if (index < PT_FPR0) { - tmp = ptrace_get_reg(child, index); + ret = ptrace_get_reg(child, index, &tmp); + if (ret) + break; } else { flush_fp_to_thread(child); /* @@ -148,7 +150,11 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, tmp = ((u64 *)child->thread.fpr) [FPRINDEX_3264(numReg)]; } else { /* register within PT_REGS struct */ - tmp = ptrace_get_reg(child, numReg); + unsigned long tmp2; + ret = ptrace_get_reg(child, numReg, &tmp2); + if (ret) + break; + tmp = tmp2; } reg32bits = ((u32*)&tmp)[part]; ret = put_user(reg32bits, (u32 __user *)data); @@ -232,7 +238,10 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, break; CHECK_FULL_REGS(child->thread.regs); if (numReg < PT_FPR0) { - unsigned long freg = ptrace_get_reg(child, numReg); + unsigned long freg; + ret = ptrace_get_reg(child, numReg, &freg); + if (ret) + break; if (index % 2) freg = (freg & ~0xfffffffful) | (data & 0xfffffffful); else -- 2.7.4