Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / arch / sparc / kernel / signal_32.c

diff --git a/kernel/arch/sparc/kernel/signal_32.c b/kernel/arch/sparc/kernel/signal_32.c
index 52aa5e4..9c0c8fd 100644 (file)
--- a/kernel/arch/sparc/kernel/signal_32.c
+++ b/kernel/arch/sparc/kernel/signal_32.c
@@ -60,10 +60,22 @@ struct rt_signal_frame {
 #define SF_ALIGNEDSZ  (((sizeof(struct signal_frame) + 7) & (~7)))
 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
 
+/* Checks if the fp is valid.  We always build signal frames which are
+ * 16-byte aligned, therefore we can always enforce that the restore
+ * frame has that property as well.
+ */
+static inline bool invalid_frame_pointer(void __user *fp, int fplen)
+{
+       if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen))
+               return true;
+
+       return false;
+}
+
 asmlinkage void do_sigreturn(struct pt_regs *regs)
 {
+       unsigned long up_psr, pc, npc, ufp;
        struct signal_frame __user *sf;
-       unsigned long up_psr, pc, npc;
        sigset_t set;
        __siginfo_fpu_t __user *fpu_save;
        __siginfo_rwin_t __user *rwin_save;
@@ -77,10 +89,13 @@ asmlinkage void do_sigreturn(struct pt_regs *regs)
        sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
 
        /* 1. Make sure we are not getting garbage from the user */
-       if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
+       if (invalid_frame_pointer(sf, sizeof(*sf)))
+               goto segv_and_exit;
+
+       if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
                goto segv_and_exit;
 
-       if (((unsigned long) sf) & 3)
+       if (ufp & 0x7)
                goto segv_and_exit;
 
        err = __get_user(pc,  &sf->info.si_regs.pc);
@@ -127,7 +142,7 @@ segv_and_exit:
 asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 {
        struct rt_signal_frame __user *sf;
-       unsigned int psr, pc, npc;
+       unsigned int psr, pc, npc, ufp;
        __siginfo_fpu_t __user *fpu_save;
        __siginfo_rwin_t __user *rwin_save;
        sigset_t set;
@@ -135,8 +150,13 @@ asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 
        synchronize_user_stack();
        sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
-       if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
-           (((unsigned long) sf) & 0x03))
+       if (invalid_frame_pointer(sf, sizeof(*sf)))
+               goto segv;
+
+       if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
+               goto segv;
+
+       if (ufp & 0x7)
                goto segv;
 
        err = __get_user(pc, &sf->regs.pc);
@@ -178,15 +198,6 @@ segv:
        force_sig(SIGSEGV, current);
 }
 
-/* Checks if the fp is valid */
-static inline int invalid_frame_pointer(void __user *fp, int fplen)
-{
-       if ((((unsigned long) fp) & 7) || !__access_ok((unsigned long)fp, fplen))
-               return 1;
-
-       return 0;
-}
-
 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
 {
        unsigned long sp = regs->u_regs[UREG_FP];