powerpc/ptrace: Fix cppcheck issue in gpr32_set_common/gpr32_get_common()

The ckpt_regs usage in gpr32_set_common/gpr32_get_common() will lead to
following cppcheck error at ifndef CONFIG_PPC_TRANSACTIONAL_MEM case:

[arch/powerpc/kernel/ptrace.c:2062]:
(error) Uninitialized variable: ckpt_regs
[arch/powerpc/kernel/ptrace.c:2130]:
(error) Uninitialized variable: ckpt_regs

The problem is due to gpr32_set_common() used ckpt_regs variable which
only makes sense at #ifdef CONFIG_PPC_TRANSACTIONAL_MEM.

This patch fix this issue by passing in "regs" parameter instead.

Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 2299bf6..a17c672 100644 (file)
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -2066,33 +2066,12 @@ static const struct user_regset_view user_ppc_native_view = {
 static int gpr32_get_common(struct task_struct *target,
                     const struct user_regset *regset,
                     unsigned int pos, unsigned int count,
-                           void *kbuf, void __user *ubuf, bool tm_active)
+                           void *kbuf, void __user *ubuf,
+                           unsigned long *regs)
 {
-       const unsigned long *regs = &target->thread.regs->gpr[0];
-       const unsigned long *ckpt_regs;
        compat_ulong_t *k = kbuf;
        compat_ulong_t __user *u = ubuf;
        compat_ulong_t reg;
-       int i;
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-       ckpt_regs = &target->thread.ckpt_regs.gpr[0];
-#endif
-       if (tm_active) {
-               regs = ckpt_regs;
-       } else {
-               if (target->thread.regs == NULL)
-                       return -EIO;
-
-               if (!FULL_REGS(target->thread.regs)) {
-                       /*
-                        * We have a partial register set.
-                        * Fill 14-31 with bogus values.
-                        */
-                       for (i = 14; i < 32; i++)
-                               target->thread.regs->gpr[i] = NV_REG_POISON;
-               }
-       }
 
        pos /= sizeof(reg);
        count /= sizeof(reg);
@@ -2134,29 +2113,13 @@ static int gpr32_get_common(struct task_struct *target,
 static int gpr32_set_common(struct task_struct *target,
                     const struct user_regset *regset,
                     unsigned int pos, unsigned int count,
-                    const void *kbuf, const void __user *ubuf, bool tm_active)
+                    const void *kbuf, const void __user *ubuf,
+                    unsigned long *regs)
 {
-       unsigned long *regs = &target->thread.regs->gpr[0];
-       unsigned long *ckpt_regs;
        const compat_ulong_t *k = kbuf;
        const compat_ulong_t __user *u = ubuf;
        compat_ulong_t reg;
 
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-       ckpt_regs = &target->thread.ckpt_regs.gpr[0];
-#endif
-
-       if (tm_active) {
-               regs = ckpt_regs;
-       } else {
-               regs = &target->thread.regs->gpr[0];
-
-               if (target->thread.regs == NULL)
-                       return -EIO;
-
-               CHECK_FULL_REGS(target->thread.regs);
-       }
-
        pos /= sizeof(reg);
        count /= sizeof(reg);
 
@@ -2221,7 +2184,8 @@ static int tm_cgpr32_get(struct task_struct *target,
                     unsigned int pos, unsigned int count,
                     void *kbuf, void __user *ubuf)
 {
-       return gpr32_get_common(target, regset, pos, count, kbuf, ubuf, 1);
+       return gpr32_get_common(target, regset, pos, count, kbuf, ubuf,
+                       &target->thread.ckpt_regs.gpr[0]);
 }
 
 static int tm_cgpr32_set(struct task_struct *target,
@@ -2229,7 +2193,8 @@ static int tm_cgpr32_set(struct task_struct *target,
                     unsigned int pos, unsigned int count,
                     const void *kbuf, const void __user *ubuf)
 {
-       return gpr32_set_common(target, regset, pos, count, kbuf, ubuf, 1);
+       return gpr32_set_common(target, regset, pos, count, kbuf, ubuf,
+                       &target->thread.ckpt_regs.gpr[0]);
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
@@ -2238,7 +2203,21 @@ static int gpr32_get(struct task_struct *target,
                     unsigned int pos, unsigned int count,
                     void *kbuf, void __user *ubuf)
 {
-       return gpr32_get_common(target, regset, pos, count, kbuf, ubuf, 0);
+       int i;
+
+       if (target->thread.regs == NULL)
+               return -EIO;
+
+       if (!FULL_REGS(target->thread.regs)) {
+               /*
+                * We have a partial register set.
+                * Fill 14-31 with bogus values.
+                */
+               for (i = 14; i < 32; i++)
+                       target->thread.regs->gpr[i] = NV_REG_POISON;
+       }
+       return gpr32_get_common(target, regset, pos, count, kbuf, ubuf,
+                       &target->thread.regs->gpr[0]);
 }
 
 static int gpr32_set(struct task_struct *target,
@@ -2246,7 +2225,12 @@ static int gpr32_set(struct task_struct *target,
                     unsigned int pos, unsigned int count,
                     const void *kbuf, const void __user *ubuf)
 {
-       return gpr32_set_common(target, regset, pos, count, kbuf, ubuf, 0);
+       if (target->thread.regs == NULL)
+               return -EIO;
+
+       CHECK_FULL_REGS(target->thread.regs);
+       return gpr32_set_common(target, regset, pos, count, kbuf, ubuf,
+                       &target->thread.regs->gpr[0]);
 }
 
 /*