x86: signal: use {get|put}_user_try and catch

Impact: use new framework

Use {get|put}_user_try, catch, and _ex in arch/x86/kernel/signal.c.

Note: this patch contains "WARNING: line over 80 characters", because when
introducing new block I insert an indent to avoid mistakes by edit.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 154 insertions, 137 deletions

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 89bb7668041d..cf34eb37fbee 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -51,24 +51,24 @@
 #endif
 
 #define COPY(x)                 {               \
-        err |= __get_user(regs->x, &sc->x);     \
+        get_user_ex(regs->x, &sc->x);           \
 }
 
 #define COPY_SEG(seg)           {                       \
                 unsigned short tmp;                     \
-                err |= __get_user(tmp, &sc->seg);       \
+                get_user_ex(tmp, &sc->seg);             \
                 regs->seg = tmp;                        \
 }
 
 #define COPY_SEG_CPL3(seg)      {                       \
                 unsigned short tmp;                     \
-                err |= __get_user(tmp, &sc->seg);       \
+                get_user_ex(tmp, &sc->seg);             \
                 regs->seg = tmp | 3;                    \
 }
 
 #define GET_SEG(seg)            {                       \
                 unsigned short tmp;                     \
-                err |= __get_user(tmp, &sc->seg);       \
+                get_user_ex(tmp, &sc->seg);             \
                 loadsegment(seg, tmp);                  \
 }
 
@@ -83,45 +83,49 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
         /* Always make any pending restarted system calls return -EINTR */
         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
+        get_user_try {
+
 #ifdef CONFIG_X86_32
-        GET_SEG(gs);
-        COPY_SEG(fs);
-        COPY_SEG(es);
-        COPY_SEG(ds);
+                GET_SEG(gs);
+                COPY_SEG(fs);
+                COPY_SEG(es);
+                COPY_SEG(ds);
 #endif /* CONFIG_X86_32 */
 
-        COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
-        COPY(dx); COPY(cx); COPY(ip);
+                COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
+                COPY(dx); COPY(cx); COPY(ip);
 
 #ifdef CONFIG_X86_64
-        COPY(r8);
-        COPY(r9);
-        COPY(r10);
-        COPY(r11);
-        COPY(r12);
-        COPY(r13);
-        COPY(r14);
-        COPY(r15);
+                COPY(r8);
+                COPY(r9);
+                COPY(r10);
+                COPY(r11);
+                COPY(r12);
+                COPY(r13);
+                COPY(r14);
+                COPY(r15);
 #endif /* CONFIG_X86_64 */
 
 #ifdef CONFIG_X86_32
-        COPY_SEG_CPL3(cs);
-        COPY_SEG_CPL3(ss);
+                COPY_SEG_CPL3(cs);
+                COPY_SEG_CPL3(ss);
 #else /* !CONFIG_X86_32 */
-        /* Kernel saves and restores only the CS segment register on signals,
-         * which is the bare minimum needed to allow mixed 32/64-bit code.
-         * App's signal handler can save/restore other segments if needed. */
-        COPY_SEG_CPL3(cs);
+                /* Kernel saves and restores only the CS segment register on signals,
+                 * which is the bare minimum needed to allow mixed 32/64-bit code.
+                 * App's signal handler can save/restore other segments if needed. */
+                COPY_SEG_CPL3(cs);
 #endif /* CONFIG_X86_32 */
 
-        err |= __get_user(tmpflags, &sc->flags);
-        regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
-        regs->orig_ax = -1;             /* disable syscall checks */
+                get_user_ex(tmpflags, &sc->flags);
+                regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+                regs->orig_ax = -1;             /* disable syscall checks */
+
+                get_user_ex(buf, &sc->fpstate);
+                err |= restore_i387_xstate(buf);
 
-        err |= __get_user(buf, &sc->fpstate);
-        err |= restore_i387_xstate(buf);
+                get_user_ex(*pax, &sc->ax);
+        } get_user_catch(err);
 
-        err |= __get_user(*pax, &sc->ax);
         return err;
 }
 
@@ -131,57 +135,60 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 {
         int err = 0;
 
+        put_user_try {
+
 #ifdef CONFIG_X86_32
-        {
-                unsigned int tmp;
+                {
+                        unsigned int tmp;
 
-                savesegment(gs, tmp);
-                err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
-        }
-        err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
-        err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
-        err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
+                        savesegment(gs, tmp);
+                        put_user_ex(tmp, (unsigned int __user *)&sc->gs);
+                }
+                put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
+                put_user_ex(regs->es, (unsigned int __user *)&sc->es);
+                put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
 #endif /* CONFIG_X86_32 */
 
-        err |= __put_user(regs->di, &sc->di);
-        err |= __put_user(regs->si, &sc->si);
-        err |= __put_user(regs->bp, &sc->bp);
-        err |= __put_user(regs->sp, &sc->sp);
-        err |= __put_user(regs->bx, &sc->bx);
-        err |= __put_user(regs->dx, &sc->dx);
-        err |= __put_user(regs->cx, &sc->cx);
-        err |= __put_user(regs->ax, &sc->ax);
+                put_user_ex(regs->di, &sc->di);
+                put_user_ex(regs->si, &sc->si);
+                put_user_ex(regs->bp, &sc->bp);
+                put_user_ex(regs->sp, &sc->sp);
+                put_user_ex(regs->bx, &sc->bx);
+                put_user_ex(regs->dx, &sc->dx);
+                put_user_ex(regs->cx, &sc->cx);
+                put_user_ex(regs->ax, &sc->ax);
 #ifdef CONFIG_X86_64
-        err |= __put_user(regs->r8, &sc->r8);
-        err |= __put_user(regs->r9, &sc->r9);
-        err |= __put_user(regs->r10, &sc->r10);
-        err |= __put_user(regs->r11, &sc->r11);
-        err |= __put_user(regs->r12, &sc->r12);
-        err |= __put_user(regs->r13, &sc->r13);
-        err |= __put_user(regs->r14, &sc->r14);
-        err |= __put_user(regs->r15, &sc->r15);
+                put_user_ex(regs->r8, &sc->r8);
+                put_user_ex(regs->r9, &sc->r9);
+                put_user_ex(regs->r10, &sc->r10);
+                put_user_ex(regs->r11, &sc->r11);
+                put_user_ex(regs->r12, &sc->r12);
+                put_user_ex(regs->r13, &sc->r13);
+                put_user_ex(regs->r14, &sc->r14);
+                put_user_ex(regs->r15, &sc->r15);
 #endif /* CONFIG_X86_64 */
 
-        err |= __put_user(current->thread.trap_no, &sc->trapno);
-        err |= __put_user(current->thread.error_code, &sc->err);
-        err |= __put_user(regs->ip, &sc->ip);
+                put_user_ex(current->thread.trap_no, &sc->trapno);
+                put_user_ex(current->thread.error_code, &sc->err);
+                put_user_ex(regs->ip, &sc->ip);
 #ifdef CONFIG_X86_32
-        err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
-        err |= __put_user(regs->flags, &sc->flags);
-        err |= __put_user(regs->sp, &sc->sp_at_signal);
-        err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
+                put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
+                put_user_ex(regs->flags, &sc->flags);
+                put_user_ex(regs->sp, &sc->sp_at_signal);
+                put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
 #else /* !CONFIG_X86_32 */
-        err |= __put_user(regs->flags, &sc->flags);
-        err |= __put_user(regs->cs, &sc->cs);
-        err |= __put_user(0, &sc->gs);
-        err |= __put_user(0, &sc->fs);
+                put_user_ex(regs->flags, &sc->flags);
+                put_user_ex(regs->cs, &sc->cs);
+                put_user_ex(0, &sc->gs);
+                put_user_ex(0, &sc->fs);
 #endif /* CONFIG_X86_32 */
 
-        err |= __put_user(fpstate, &sc->fpstate);
+                put_user_ex(fpstate, &sc->fpstate);
 
-        /* non-iBCS2 extensions.. */
-        err |= __put_user(mask, &sc->oldmask);
-        err |= __put_user(current->thread.cr2, &sc->cr2);
+                /* non-iBCS2 extensions.. */
+                put_user_ex(mask, &sc->oldmask);
+                put_user_ex(current->thread.cr2, &sc->cr2);
+        } put_user_catch(err);
 
         return err;
 }
@@ -336,43 +343,41 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
                 return -EFAULT;
 
-        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)
-                return -EFAULT;
-
-        /* Create the ucontext.  */
-        if (cpu_has_xsave)
-                err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
-        else
-                err |= __put_user(0, &frame->uc.uc_flags);
-        err |= __put_user(0, &frame->uc.uc_link);
-        err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
-        err |= __put_user(sas_ss_flags(regs->sp),
-                          &frame->uc.uc_stack.ss_flags);
-        err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
-        err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
-                                regs, set->sig[0]);
-        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-        if (err)
-                return -EFAULT;
+        put_user_try {
+                put_user_ex(sig, &frame->sig);
+                put_user_ex(&frame->info, &frame->pinfo);
+                put_user_ex(&frame->uc, &frame->puc);
+                err |= copy_siginfo_to_user(&frame->info, info);
 
-        /* Set up to return from userspace.  */
-        restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
-        if (ka->sa.sa_flags & SA_RESTORER)
-                restorer = ka->sa.sa_restorer;
-        err |= __put_user(restorer, &frame->pretcode);
+                /* Create the ucontext.  */
+                if (cpu_has_xsave)
+                        put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
+                else
+                        put_user_ex(0, &frame->uc.uc_flags);
+                put_user_ex(0, &frame->uc.uc_link);
+                put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+                put_user_ex(sas_ss_flags(regs->sp),
+                            &frame->uc.uc_stack.ss_flags);
+                put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+                err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
+                                        regs, set->sig[0]);
+                err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+                /* Set up to return from userspace.  */
+                restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
+                if (ka->sa.sa_flags & SA_RESTORER)
+                        restorer = ka->sa.sa_restorer;
+                put_user_ex(restorer, &frame->pretcode);
 
-        /*
-         * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
-         *
-         * WE DO NOT USE IT ANY MORE! It's only left here for historical
-         * reasons and because gdb uses it as a signature to notice
-         * signal handler stack frames.
-         */
-        err |= __put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
+                /*
+                 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
+                 *
+                 * WE DO NOT USE IT ANY MORE! It's only left here for historical
+                 * reasons and because gdb uses it as a signature to notice
+                 * signal handler stack frames.
+                 */
+                put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
+        } put_user_catch(err);
 
         if (err)
                 return -EFAULT;
@@ -436,28 +441,30 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                         return -EFAULT;
         }
 
-        /* Create the ucontext.  */
-        if (cpu_has_xsave)
-                err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
-        else
-                err |= __put_user(0, &frame->uc.uc_flags);
-        err |= __put_user(0, &frame->uc.uc_link);
-        err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
-        err |= __put_user(sas_ss_flags(regs->sp),
-                          &frame->uc.uc_stack.ss_flags);
-        err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
-        err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
-        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-
-        /* Set up to return from userspace.  If provided, use a stub
-           already in userspace.  */
-        /* x86-64 should always use SA_RESTORER. */
-        if (ka->sa.sa_flags & SA_RESTORER) {
-                err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
-        } else {
-                /* could use a vstub here */
-                return -EFAULT;
-        }
+        put_user_try {
+                /* Create the ucontext.  */
+                if (cpu_has_xsave)
+                        put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
+                else
+                        put_user_ex(0, &frame->uc.uc_flags);
+                put_user_ex(0, &frame->uc.uc_link);
+                put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+                put_user_ex(sas_ss_flags(regs->sp),
+                            &frame->uc.uc_stack.ss_flags);
+                put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+                err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
+                err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+                /* Set up to return from userspace.  If provided, use a stub
+                   already in userspace.  */
+                /* x86-64 should always use SA_RESTORER. */
+                if (ka->sa.sa_flags & SA_RESTORER) {
+                        put_user_ex(ka->sa.sa_restorer, &frame->pretcode);
+                } else {
+                        /* could use a vstub here */
+                        err |= -EFAULT;
+                }
+        } put_user_catch(err);
 
         if (err)
                 return -EFAULT;
@@ -509,31 +516,41 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
               struct old_sigaction __user *oact)
 {
         struct k_sigaction new_ka, old_ka;
-        int ret;
+        int ret = 0;
 
         if (act) {
                 old_sigset_t mask;
 
-                if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
-                    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
-                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+                if (!access_ok(VERIFY_READ, act, sizeof(*act)))
                         return -EFAULT;
 
-                __get_user(new_ka.sa.sa_flags, &act->sa_flags);
-                __get_user(mask, &act->sa_mask);
+                get_user_try {
+                        get_user_ex(new_ka.sa.sa_handler, &act->sa_handler);
+                        get_user_ex(new_ka.sa.sa_flags, &act->sa_flags);
+                        get_user_ex(mask, &act->sa_mask);
+                        get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer);
+                } get_user_catch(ret);
+
+                if (ret)
+                        return -EFAULT;
                 siginitset(&new_ka.sa.sa_mask, mask);
         }
 
         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 
         if (!ret && oact) {
-                if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
-                    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
-                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+                if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
                         return -EFAULT;
 
-                __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
-                __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+                put_user_try {
+                        put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler);
+                        put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags);
+                        put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+                        put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer);
+                } put_user_catch(ret);
+
+                if (ret)
+                        return -EFAULT;
         }
 
         return ret;