Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / arch / sparc / kernel / signal32.c

diff --git a/kernel/arch/sparc/kernel/signal32.c b/kernel/arch/sparc/kernel/signal32.c
index 4eed773..77655f0 100644 (file)
--- a/kernel/arch/sparc/kernel/signal32.c
+++ b/kernel/arch/sparc/kernel/signal32.c
@@ -138,12 +138,24 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
        return 0;
 }
 
+/* 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 bool invalid_frame_pointer(void __user *fp, int fplen)
+{
+       if ((((unsigned long) fp) & 15) ||
+           ((unsigned long)fp) > 0x100000000ULL - fplen)
+               return true;
+       return false;
+}
+
 void do_sigreturn32(struct pt_regs *regs)
 {
        struct signal_frame32 __user *sf;
        compat_uptr_t fpu_save;
        compat_uptr_t rwin_save;
-       unsigned int psr;
+       unsigned int psr, ufp;
        unsigned pc, npc;
        sigset_t set;
        compat_sigset_t seta;
@@ -158,11 +170,16 @@ void do_sigreturn32(struct pt_regs *regs)
        sf = (struct signal_frame32 __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)) ||
-           (((unsigned long) sf) & 3))
+       if (invalid_frame_pointer(sf, sizeof(*sf)))
+               goto segv;
+
+       if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
+               goto segv;
+
+       if (ufp & 0x7)
                goto segv;
 
-       if (get_user(pc, &sf->info.si_regs.pc) ||
+       if (__get_user(pc, &sf->info.si_regs.pc) ||
            __get_user(npc, &sf->info.si_regs.npc))
                goto segv;
 
@@ -227,7 +244,7 @@ segv:
 asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
 {
        struct rt_signal_frame32 __user *sf;
-       unsigned int psr, pc, npc;
+       unsigned int psr, pc, npc, ufp;
        compat_uptr_t fpu_save;
        compat_uptr_t rwin_save;
        sigset_t set;
@@ -242,11 +259,16 @@ asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
        sf = (struct rt_signal_frame32 __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)) ||
-           (((unsigned long) sf) & 3))
+       if (invalid_frame_pointer(sf, sizeof(*sf)))
                goto segv;
 
-       if (get_user(pc, &sf->regs.pc) || 
+       if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
+               goto segv;
+
+       if (ufp & 0x7)
+               goto segv;
+
+       if (__get_user(pc, &sf->regs.pc) ||
            __get_user(npc, &sf->regs.npc))
                goto segv;
 
@@ -307,14 +329,6 @@ segv:
        force_sig(SIGSEGV, current);
 }
 
-/* Checks if the fp is valid */
-static int invalid_frame_pointer(void __user *fp, int fplen)
-{
-       if ((((unsigned long) fp) & 7) || ((unsigned long)fp) > 0x100000000ULL - fplen)
-               return 1;
-       return 0;
-}
-
 static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
 {
        unsigned long sp;