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Diffstat (limited to 'arch/powerpc/kernel/signal_32.c')
-rw-r--r--arch/powerpc/kernel/signal_32.c52
1 files changed, 29 insertions, 23 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 3e80aa32b8b..b13abf30599 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -410,7 +410,7 @@ inline unsigned long copy_fpr_from_user(struct task_struct *task,
* altivec/spe instructions at some point.
*/
static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
- int sigret)
+ int sigret, int ctx_has_vsx_region)
{
unsigned long msr = regs->msr;
@@ -451,7 +451,7 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
* the saved MSR value to indicate that frame->mc_vregs
* contains valid data
*/
- if (current->thread.used_vsr) {
+ if (current->thread.used_vsr && ctx_has_vsx_region) {
__giveup_vsx(current);
if (copy_vsx_to_user(&frame->mc_vsregs, current))
return 1;
@@ -858,11 +858,11 @@ int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
frame = &rt_sf->uc.uc_mcontext;
addr = frame;
if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
- if (save_user_regs(regs, frame, 0))
+ if (save_user_regs(regs, frame, 0, 1))
goto badframe;
regs->link = current->mm->context.vdso_base + vdso32_rt_sigtramp;
} else {
- if (save_user_regs(regs, frame, __NR_rt_sigreturn))
+ if (save_user_regs(regs, frame, __NR_rt_sigreturn, 1))
goto badframe;
regs->link = (unsigned long) frame->tramp;
}
@@ -936,13 +936,26 @@ long sys_swapcontext(struct ucontext __user *old_ctx,
int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
{
unsigned char tmp;
+ int ctx_has_vsx_region = 0;
#ifdef CONFIG_PPC64
unsigned long new_msr = 0;
- if (new_ctx &&
- __get_user(new_msr, &new_ctx->uc_mcontext.mc_gregs[PT_MSR]))
- return -EFAULT;
+ if (new_ctx) {
+ struct mcontext __user *mcp;
+ u32 cmcp;
+
+ /*
+ * Get pointer to the real mcontext. No need for
+ * access_ok since we are dealing with compat
+ * pointers.
+ */
+ if (__get_user(cmcp, &new_ctx->uc_regs))
+ return -EFAULT;
+ mcp = (struct mcontext __user *)(u64)cmcp;
+ if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
+ return -EFAULT;
+ }
/*
* Check that the context is not smaller than the original
* size (with VMX but without VSX)
@@ -956,16 +969,9 @@ long sys_swapcontext(struct ucontext __user *old_ctx,
if ((ctx_size < sizeof(struct ucontext)) &&
(new_msr & MSR_VSX))
return -EINVAL;
-#ifdef CONFIG_VSX
- /*
- * If userspace doesn't provide enough room for VSX data,
- * but current thread has used VSX, we don't have anywhere
- * to store the full context back into.
- */
- if ((ctx_size < sizeof(struct ucontext)) &&
- (current->thread.used_vsr && old_ctx))
- return -EINVAL;
-#endif
+ /* Does the context have enough room to store VSX data? */
+ if (ctx_size >= sizeof(struct ucontext))
+ ctx_has_vsx_region = 1;
#else
/* Context size is for future use. Right now, we only make sure
* we are passed something we understand
@@ -985,17 +991,17 @@ long sys_swapcontext(struct ucontext __user *old_ctx,
*/
mctx = (struct mcontext __user *)
((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
- if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
- || save_user_regs(regs, mctx, 0)
+ if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
+ || save_user_regs(regs, mctx, 0, ctx_has_vsx_region)
|| put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
|| __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
return -EFAULT;
}
if (new_ctx == NULL)
return 0;
- if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
+ if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
|| __get_user(tmp, (u8 __user *) new_ctx)
- || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
+ || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
return -EFAULT;
/*
@@ -1196,11 +1202,11 @@ int handle_signal32(unsigned long sig, struct k_sigaction *ka,
goto badframe;
if (vdso32_sigtramp && current->mm->context.vdso_base) {
- if (save_user_regs(regs, &frame->mctx, 0))
+ if (save_user_regs(regs, &frame->mctx, 0, 1))
goto badframe;
regs->link = current->mm->context.vdso_base + vdso32_sigtramp;
} else {
- if (save_user_regs(regs, &frame->mctx, __NR_sigreturn))
+ if (save_user_regs(regs, &frame->mctx, __NR_sigreturn, 1))
goto badframe;
regs->link = (unsigned long) frame->mctx.tramp;
}