1 files changed, 134 insertions, 88 deletions

diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index b21070ea33a4..d6dd057d0f22 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -27,6 +27,7 @@
 #include <asm/uaccess.h>
 #include <asm/i387.h>
 #include <asm/vdso.h>
+#include <asm/syscall.h>
 #include <asm/syscalls.h>
 
 #include "sigframe.h"
@@ -112,6 +113,27 @@ asmlinkage int sys_sigaltstack(unsigned long bx)
         return do_sigaltstack(uss, uoss, regs->sp);
 }
 
+#define COPY(x)                 {               \
+        err |= __get_user(regs->x, &sc->x);     \
+}
+
+#define COPY_SEG(seg)           {                       \
+                unsigned short tmp;                     \
+                err |= __get_user(tmp, &sc->seg);       \
+                regs->seg = tmp;                        \
+}
+
+#define COPY_SEG_STRICT(seg)    {                       \
+                unsigned short tmp;                     \
+                err |= __get_user(tmp, &sc->seg);       \
+                regs->seg = tmp | 3;                    \
+}
+
+#define GET_SEG(seg)            {                       \
+                unsigned short tmp;                     \
+                err |= __get_user(tmp, &sc->seg);       \
+                loadsegment(seg, tmp);                  \
+}
 
 /*
  * Do a signal return; undo the signal stack.
@@ -120,28 +142,13 @@ static int
 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
                    unsigned long *pax)
 {
+        void __user *buf;
+        unsigned int tmpflags;
         unsigned int err = 0;
 
         /* Always make any pending restarted system calls return -EINTR */
         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
-#define COPY(x)         err |= __get_user(regs->x, &sc->x)
-
-#define COPY_SEG(seg)                                                   \
-        { unsigned short tmp;                                           \
-          err |= __get_user(tmp, &sc->seg);                             \
-          regs->seg = tmp; }
-
-#define COPY_SEG_STRICT(seg)                                            \
-        { unsigned short tmp;                                           \
-          err |= __get_user(tmp, &sc->seg);                             \
-          regs->seg = tmp|3; }
-
-#define GET_SEG(seg)                                                    \
-        { unsigned short tmp;                                           \
-          err |= __get_user(tmp, &sc->seg);                             \
-          loadsegment(seg, tmp); }
-
         GET_SEG(gs);
         COPY_SEG(fs);
         COPY_SEG(es);
@@ -151,21 +158,12 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
         COPY_SEG_STRICT(cs);
         COPY_SEG_STRICT(ss);
 
-        {
-                unsigned int tmpflags;
-
-                err |= __get_user(tmpflags, &sc->flags);
-                regs->flags = (regs->flags & ~FIX_EFLAGS) |
-                                                (tmpflags & FIX_EFLAGS);
-                regs->orig_ax = -1;             /* disable syscall checks */
-        }
-
-        {
-                void __user *buf;
+        err |= __get_user(tmpflags, &sc->flags);
+        regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+        regs->orig_ax = -1;             /* disable syscall checks */
 
-                err |= __get_user(buf, &sc->fpstate);
-                err |= restore_i387_xstate(buf);
-        }
+        err |= __get_user(buf, &sc->fpstate);
+        err |= restore_i387_xstate(buf);
 
         err |= __get_user(*pax, &sc->ax);
         return err;
@@ -214,9 +212,8 @@ badframe:
         return 0;
 }
 
-asmlinkage int sys_rt_sigreturn(unsigned long __unused)
+static long do_rt_sigreturn(struct pt_regs *regs)
 {
-        struct pt_regs *regs = (struct pt_regs *)&__unused;
         struct rt_sigframe __user *frame;
         unsigned long ax;
         sigset_t set;
@@ -242,10 +239,17 @@ asmlinkage int sys_rt_sigreturn(unsigned long __unused)
         return ax;
 
 badframe:
-        force_sig(SIGSEGV, current);
+        signal_fault(regs, frame, "rt_sigreturn");
         return 0;
 }
 
+asmlinkage int sys_rt_sigreturn(unsigned long __unused)
+{
+        struct pt_regs *regs = (struct pt_regs *)&__unused;
+
+        return do_rt_sigreturn(regs);
+}
+
 /*
  * Set up a signal frame.
  */
@@ -337,39 +341,29 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 }
 
 static int
-setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
-            struct pt_regs *regs)
+__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
+              struct pt_regs *regs)
 {
         struct sigframe __user *frame;
         void __user *restorer;
         int err = 0;
-        int usig;
         void __user *fpstate = NULL;
 
         frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 
         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
-                goto give_sigsegv;
+                return -EFAULT;
 
-        usig = current_thread_info()->exec_domain
-                && current_thread_info()->exec_domain->signal_invmap
-                && sig < 32
-                ? current_thread_info()->exec_domain->signal_invmap[sig]
-                : sig;
+        if (__put_user(sig, &frame->sig))
+                return -EFAULT;
 
-        err = __put_user(usig, &frame->sig);
-        if (err)
-                goto give_sigsegv;
-
-        err = setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]);
-        if (err)
-                goto give_sigsegv;
+        if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
+                return -EFAULT;
 
         if (_NSIG_WORDS > 1) {
-                err = __copy_to_user(&frame->extramask, &set->sig[1],
-                                      sizeof(frame->extramask));
-                if (err)
-                        goto give_sigsegv;
+                if (__copy_to_user(&frame->extramask, &set->sig[1],
+                                   sizeof(frame->extramask)))
+                        return -EFAULT;
         }
 
         if (current->mm->context.vdso)
@@ -394,7 +388,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
         err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
 
         if (err)
-                goto give_sigsegv;
+                return -EFAULT;
 
         /* Set up registers for signal handler */
         regs->sp = (unsigned long)frame;
@@ -409,38 +403,27 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
         regs->cs = __USER_CS;
 
         return 0;
-
-give_sigsegv:
-        force_sigsegv(sig, current);
-        return -EFAULT;
 }
 
-static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
-                          sigset_t *set, struct pt_regs *regs)
+static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+                            sigset_t *set, struct pt_regs *regs)
 {
         struct rt_sigframe __user *frame;
         void __user *restorer;
         int err = 0;
-        int usig;
         void __user *fpstate = NULL;
 
         frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 
         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
-                goto give_sigsegv;
-
-        usig = current_thread_info()->exec_domain
-                && current_thread_info()->exec_domain->signal_invmap
-                && sig < 32
-                ? current_thread_info()->exec_domain->signal_invmap[sig]
-                : sig;
+                return -EFAULT;
 
-        err |= __put_user(usig, &frame->sig);
+        err |= __put_user(sig, &frame->sig);
         err |= __put_user(&frame->info, &frame->pinfo);
         err |= __put_user(&frame->uc, &frame->puc);
         err |= copy_siginfo_to_user(&frame->info, info);
         if (err)
-                goto give_sigsegv;
+                return -EFAULT;
 
         /* Create the ucontext.  */
         if (cpu_has_xsave)
@@ -456,7 +439,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                                 regs, set->sig[0]);
         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
         if (err)
-                goto give_sigsegv;
+                return -EFAULT;
 
         /* Set up to return from userspace.  */
         restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
@@ -476,12 +459,12 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
         err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
 
         if (err)
-                goto give_sigsegv;
+                return -EFAULT;
 
         /* Set up registers for signal handler */
         regs->sp = (unsigned long)frame;
         regs->ip = (unsigned long)ka->sa.sa_handler;
-        regs->ax = (unsigned long)usig;
+        regs->ax = (unsigned long)sig;
         regs->dx = (unsigned long)&frame->info;
         regs->cx = (unsigned long)&frame->uc;
 
@@ -491,15 +474,48 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
         regs->cs = __USER_CS;
 
         return 0;
-
-give_sigsegv:
-        force_sigsegv(sig, current);
-        return -EFAULT;
 }
 
 /*
  * OK, we're invoking a handler:
  */
+static int signr_convert(int sig)
+{
+        struct thread_info *info = current_thread_info();
+
+        if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
+                return info->exec_domain->signal_invmap[sig];
+        return sig;
+}
+
+#define is_ia32 1
+#define ia32_setup_frame        __setup_frame
+#define ia32_setup_rt_frame     __setup_rt_frame
+
+static int
+setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+               sigset_t *set, struct pt_regs *regs)
+{
+        int usig = signr_convert(sig);
+        int ret;
+
+        /* Set up the stack frame */
+        if (is_ia32) {
+                if (ka->sa.sa_flags & SA_SIGINFO)
+                        ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
+                else
+                        ret = ia32_setup_frame(usig, ka, set, regs);
+        } else
+                ret = __setup_rt_frame(sig, ka, info, set, regs);
+
+        if (ret) {
+                force_sigsegv(sig, current);
+                return -EFAULT;
+        }
+
+        return ret;
+}
+
 static int
 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
               sigset_t *oldset, struct pt_regs *regs)
@@ -507,9 +523,9 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
         int ret;
 
         /* Are we from a system call? */
-        if ((long)regs->orig_ax >= 0) {
+        if (syscall_get_nr(current, regs) >= 0) {
                 /* If so, check system call restarting.. */
-                switch (regs->ax) {
+                switch (syscall_get_error(current, regs)) {
                 case -ERESTART_RESTARTBLOCK:
                 case -ERESTARTNOHAND:
                         regs->ax = -EINTR;
@@ -536,15 +552,20 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
             likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
                 regs->flags &= ~X86_EFLAGS_TF;
 
-        /* Set up the stack frame */
-        if (ka->sa.sa_flags & SA_SIGINFO)
-                ret = setup_rt_frame(sig, ka, info, oldset, regs);
-        else
-                ret = setup_frame(sig, ka, oldset, regs);
+        ret = setup_rt_frame(sig, ka, info, oldset, regs);
 
         if (ret)
                 return ret;
 
+#ifdef CONFIG_X86_64
+        /*
+         * This has nothing to do with segment registers,
+         * despite the name.  This magic affects uaccess.h
+         * macros' behavior.  Reset it to the normal setting.
+         */
+        set_fs(USER_DS);
+#endif
+
         /*
          * Clear the direction flag as per the ABI for function entry.
          */
@@ -571,6 +592,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
         return 0;
 }
 
+#define NR_restart_syscall      __NR_restart_syscall
 /*
  * Note that 'init' is a special process: it doesn't get signals it doesn't
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
@@ -623,9 +645,9 @@ static void do_signal(struct pt_regs *regs)
         }
 
         /* Did we come from a system call? */
-        if ((long)regs->orig_ax >= 0) {
+        if (syscall_get_nr(current, regs) >= 0) {
                 /* Restart the system call - no handlers present */
-                switch (regs->ax) {
+                switch (syscall_get_error(current, regs)) {
                 case -ERESTARTNOHAND:
                 case -ERESTARTSYS:
                 case -ERESTARTNOINTR:
@@ -634,7 +656,7 @@ static void do_signal(struct pt_regs *regs)
                         break;
 
                 case -ERESTART_RESTARTBLOCK:
-                        regs->ax = __NR_restart_syscall;
+                        regs->ax = NR_restart_syscall;
                         regs->ip -= 2;
                         break;
                 }
@@ -657,6 +679,12 @@ static void do_signal(struct pt_regs *regs)
 void
 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
 {
+#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
+        /* notify userspace of pending MCEs */
+        if (thread_info_flags & _TIF_MCE_NOTIFY)
+                mce_notify_user();
+#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
+
         /* deal with pending signal delivery */
         if (thread_info_flags & _TIF_SIGPENDING)
                 do_signal(regs);
@@ -666,5 +694,23 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
                 tracehook_notify_resume(regs);
         }
 
+#ifdef CONFIG_X86_32
         clear_thread_flag(TIF_IRET);
+#endif /* CONFIG_X86_32 */
+}
+
+void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
+{
+        struct task_struct *me = current;
+
+        if (show_unhandled_signals && printk_ratelimit()) {
+                printk(KERN_INFO
+                       "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
+                       me->comm, me->pid, where, frame,
+                       regs->ip, regs->sp, regs->orig_ax);
+                print_vma_addr(" in ", regs->ip);
+                printk(KERN_CONT "\n");
+        }
+
+        force_sig(SIGSEGV, me);
 }