Merge signal handler branch

2 files changed, 160 insertions, 126 deletions

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index f094277485c8..1ce05ec086c6 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -134,17 +134,6 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 
 #ifdef CONFIG_IWMMXT
 
-/* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */
-#define IWMMXT_STORAGE_SIZE     (0x98 + 8)
-#define IWMMXT_MAGIC0           0x12ef842a
-#define IWMMXT_MAGIC1           0x1c07ca71
-
-struct iwmmxt_sigframe {
-        unsigned long   magic0;
-        unsigned long   magic1;
-        unsigned long   storage[0x98/4];
-};
-
 static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
 {
         char kbuf[sizeof(*frame) + 8];
@@ -152,8 +141,8 @@ static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
 
         /* the iWMMXt context must be 64 bit aligned */
         kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
-        kframe->magic0 = IWMMXT_MAGIC0;
-        kframe->magic1 = IWMMXT_MAGIC1;
+        kframe->magic = IWMMXT_MAGIC;
+        kframe->size = IWMMXT_STORAGE_SIZE;
         iwmmxt_task_copy(current_thread_info(), &kframe->storage);
         return __copy_to_user(frame, kframe, sizeof(*frame));
 }
@@ -167,8 +156,8 @@ static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
         kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
         if (__copy_from_user(kframe, frame, sizeof(*frame)))
                 return -1;
-        if (kframe->magic0 != IWMMXT_MAGIC0 ||
-            kframe->magic1 != IWMMXT_MAGIC1)
+        if (kframe->magic != IWMMXT_MAGIC ||
+            kframe->size != IWMMXT_STORAGE_SIZE)
                 return -1;
         iwmmxt_task_restore(current_thread_info(), &kframe->storage);
         return 0;
@@ -177,70 +166,61 @@ static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
 #endif
 
 /*
- * Auxiliary signal frame.  This saves stuff like FP state.
- * The layout of this structure is not part of the user ABI.
- */
-struct aux_sigframe {
-#ifdef CONFIG_IWMMXT
-        struct iwmmxt_sigframe  iwmmxt;
-#endif
-#ifdef CONFIG_VFP
-        union vfp_state         vfp;
-#endif
-};
-
-/*
  * Do a signal return; undo the signal stack.  These are aligned to 64-bit.
  */
 struct sigframe {
-        struct sigcontext sc;
-        unsigned long extramask[_NSIG_WORDS-1];
+        struct ucontext uc;
         unsigned long retcode[2];
-        struct aux_sigframe aux __attribute__((aligned(8)));
 };
 
 struct rt_sigframe {
-        struct siginfo __user *pinfo;
-        void __user *puc;
         struct siginfo info;
-        struct ucontext uc;
-        unsigned long retcode[2];
-        struct aux_sigframe aux __attribute__((aligned(8)));
+        struct sigframe sig;
 };
 
-static int
-restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
-                   struct aux_sigframe __user *aux)
+static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
 {
-        int err = 0;
+        struct aux_sigframe __user *aux;
+        sigset_t set;
+        int err;
+
+        err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
+        if (err == 0) {
+                sigdelsetmask(&set, ~_BLOCKABLE);
+                spin_lock_irq(&current->sighand->siglock);
+                current->blocked = set;
+                recalc_sigpending();
+                spin_unlock_irq(&current->sighand->siglock);
+        }
 
-        __get_user_error(regs->ARM_r0, &sc->arm_r0, err);
-        __get_user_error(regs->ARM_r1, &sc->arm_r1, err);
-        __get_user_error(regs->ARM_r2, &sc->arm_r2, err);
-        __get_user_error(regs->ARM_r3, &sc->arm_r3, err);
-        __get_user_error(regs->ARM_r4, &sc->arm_r4, err);
-        __get_user_error(regs->ARM_r5, &sc->arm_r5, err);
-        __get_user_error(regs->ARM_r6, &sc->arm_r6, err);
-        __get_user_error(regs->ARM_r7, &sc->arm_r7, err);
-        __get_user_error(regs->ARM_r8, &sc->arm_r8, err);
-        __get_user_error(regs->ARM_r9, &sc->arm_r9, err);
-        __get_user_error(regs->ARM_r10, &sc->arm_r10, err);
-        __get_user_error(regs->ARM_fp, &sc->arm_fp, err);
-        __get_user_error(regs->ARM_ip, &sc->arm_ip, err);
-        __get_user_error(regs->ARM_sp, &sc->arm_sp, err);
-        __get_user_error(regs->ARM_lr, &sc->arm_lr, err);
-        __get_user_error(regs->ARM_pc, &sc->arm_pc, err);
-        __get_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err);
+        __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
+        __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
+        __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
+        __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
+        __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
+        __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
+        __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
+        __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
+        __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
+        __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
+        __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
+        __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
+        __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
+        __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
+        __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
+        __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
+        __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
 
         err |= !valid_user_regs(regs);
 
+        aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
 #ifdef CONFIG_IWMMXT
         if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
                 err |= restore_iwmmxt_context(&aux->iwmmxt);
 #endif
 #ifdef CONFIG_VFP
 //      if (err == 0)
-//              err |= vfp_restore_state(&aux->vfp);
+//              err |= vfp_restore_state(&sf->aux.vfp);
 #endif
 
         return err;
@@ -249,7 +229,6 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 asmlinkage int sys_sigreturn(struct pt_regs *regs)
 {
         struct sigframe __user *frame;
-        sigset_t set;
 
         /* Always make any pending restarted system calls return -EINTR */
         current_thread_info()->restart_block.fn = do_no_restart_syscall;
@@ -266,19 +245,8 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs)
 
         if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
                 goto badframe;
-        if (__get_user(set.sig[0], &frame->sc.oldmask)
-            || (_NSIG_WORDS > 1
-                && __copy_from_user(&set.sig[1], &frame->extramask,
-                                    sizeof(frame->extramask))))
-                goto badframe;
-
-        sigdelsetmask(&set, ~_BLOCKABLE);
-        spin_lock_irq(&current->sighand->siglock);
-        current->blocked = set;
-        recalc_sigpending();
-        spin_unlock_irq(&current->sighand->siglock);
 
-        if (restore_sigcontext(regs, &frame->sc, &frame->aux))
+        if (restore_sigframe(regs, frame))
                 goto badframe;
 
         /* Send SIGTRAP if we're single-stepping */
@@ -297,7 +265,6 @@ badframe:
 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 {
         struct rt_sigframe __user *frame;
-        sigset_t set;
 
         /* Always make any pending restarted system calls return -EINTR */
         current_thread_info()->restart_block.fn = do_no_restart_syscall;
@@ -314,19 +281,11 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 
         if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
                 goto badframe;
-        if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
-                goto badframe;
 
-        sigdelsetmask(&set, ~_BLOCKABLE);
-        spin_lock_irq(&current->sighand->siglock);
-        current->blocked = set;
-        recalc_sigpending();
-        spin_unlock_irq(&current->sighand->siglock);
-
-        if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &frame->aux))
+        if (restore_sigframe(regs, &frame->sig))
                 goto badframe;
 
-        if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
+        if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
                 goto badframe;
 
         /* Send SIGTRAP if we're single-stepping */
@@ -343,42 +302,46 @@ badframe:
 }
 
 static int
-setup_sigcontext(struct sigcontext __user *sc, struct aux_sigframe __user *aux,
-                 struct pt_regs *regs, unsigned long mask)
+setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
 {
+        struct aux_sigframe __user *aux;
         int err = 0;
 
-        __put_user_error(regs->ARM_r0, &sc->arm_r0, err);
-        __put_user_error(regs->ARM_r1, &sc->arm_r1, err);
-        __put_user_error(regs->ARM_r2, &sc->arm_r2, err);
-        __put_user_error(regs->ARM_r3, &sc->arm_r3, err);
-        __put_user_error(regs->ARM_r4, &sc->arm_r4, err);
-        __put_user_error(regs->ARM_r5, &sc->arm_r5, err);
-        __put_user_error(regs->ARM_r6, &sc->arm_r6, err);
-        __put_user_error(regs->ARM_r7, &sc->arm_r7, err);
-        __put_user_error(regs->ARM_r8, &sc->arm_r8, err);
-        __put_user_error(regs->ARM_r9, &sc->arm_r9, err);
-        __put_user_error(regs->ARM_r10, &sc->arm_r10, err);
-        __put_user_error(regs->ARM_fp, &sc->arm_fp, err);
-        __put_user_error(regs->ARM_ip, &sc->arm_ip, err);
-        __put_user_error(regs->ARM_sp, &sc->arm_sp, err);
-        __put_user_error(regs->ARM_lr, &sc->arm_lr, err);
-        __put_user_error(regs->ARM_pc, &sc->arm_pc, err);
-        __put_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err);
-
-        __put_user_error(current->thread.trap_no, &sc->trap_no, err);
-        __put_user_error(current->thread.error_code, &sc->error_code, err);
-        __put_user_error(current->thread.address, &sc->fault_address, err);
-        __put_user_error(mask, &sc->oldmask, err);
-
+        __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
+        __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
+        __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
+        __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
+        __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
+        __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
+        __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
+        __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
+        __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
+        __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
+        __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
+        __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
+        __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
+        __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
+        __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
+        __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
+        __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
+
+        __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
+        __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
+        __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
+        __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
+
+        err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
+
+        aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
 #ifdef CONFIG_IWMMXT
         if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
                 err |= preserve_iwmmxt_context(&aux->iwmmxt);
 #endif
 #ifdef CONFIG_VFP
 //      if (err == 0)
-//              err |= vfp_save_state(&aux->vfp);
+//              err |= vfp_save_state(&sf->aux.vfp);
 #endif
+        __put_user_error(0, &aux->end_magic, err);
 
         return err;
 }
@@ -487,13 +450,12 @@ setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *reg
         if (!frame)
                 return 1;
 
-        err |= setup_sigcontext(&frame->sc, &frame->aux, regs, set->sig[0]);
-
-        if (_NSIG_WORDS > 1) {
-                err |= __copy_to_user(frame->extramask, &set->sig[1],
-                                      sizeof(frame->extramask));
-        }
+        /*
+         * Set uc.uc_flags to a value which sc.trap_no would never have.
+         */
+        __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
 
+        err |= setup_sigframe(frame, regs, set);
         if (err == 0)
                 err = setup_return(regs, ka, frame->retcode, frame, usig);
 
@@ -511,25 +473,20 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
         if (!frame)
                 return 1;
 
-        __put_user_error(&frame->info, &frame->pinfo, err);
-        __put_user_error(&frame->uc, &frame->puc, err);
         err |= copy_siginfo_to_user(&frame->info, info);
 
-        __put_user_error(0, &frame->uc.uc_flags, err);
-        __put_user_error(NULL, &frame->uc.uc_link, err);
+        __put_user_error(0, &frame->sig.uc.uc_flags, err);
+        __put_user_error(NULL, &frame->sig.uc.uc_link, err);
 
         memset(&stack, 0, sizeof(stack));
         stack.ss_sp = (void __user *)current->sas_ss_sp;
         stack.ss_flags = sas_ss_flags(regs->ARM_sp);
         stack.ss_size = current->sas_ss_size;
-        err |= __copy_to_user(&frame->uc.uc_stack, &stack, sizeof(stack));
-
-        err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->aux,
-                                regs, set->sig[0]);
-        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+        err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
 
+        err |= setup_sigframe(&frame->sig, regs, set);
         if (err == 0)
-                err = setup_return(regs, ka, frame->retcode, frame, usig);
+                err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
 
         if (err == 0) {
                 /*
@@ -538,7 +495,7 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
                  *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
                  */
                 regs->ARM_r1 = (unsigned long)&frame->info;
-                regs->ARM_r2 = (unsigned long)&frame->uc;
+                regs->ARM_r2 = (unsigned long)&frame->sig.uc;
         }
 
         return err;
diff --git a/include/asm-arm/ucontext.h b/include/asm-arm/ucontext.h
index f853130137cc..9e6f7ca9f5ae 100644
--- a/include/asm-arm/ucontext.h
+++ b/include/asm-arm/ucontext.h
@@ -1,12 +1,89 @@
 #ifndef _ASMARM_UCONTEXT_H
 #define _ASMARM_UCONTEXT_H
 
+#include <asm/fpstate.h>
+
+/*
+ * struct sigcontext only has room for the basic registers, but struct
+ * ucontext now has room for all registers which need to be saved and
+ * restored.  Coprocessor registers are stored in uc_regspace.  Each
+ * coprocessor's saved state should start with a documented 32-bit magic
+ * number, followed by a 32-bit word giving the coproccesor's saved size.
+ * uc_regspace may be expanded if necessary, although this takes some
+ * coordination with glibc.
+ */
+
 struct ucontext {
         unsigned long     uc_flags;
         struct ucontext  *uc_link;
         stack_t           uc_stack;
         struct sigcontext uc_mcontext;
-        sigset_t          uc_sigmask;   /* mask last for extensibility */
+        sigset_t          uc_sigmask;
+        /* Allow for uc_sigmask growth.  Glibc uses a 1024-bit sigset_t.  */
+        int               __unused[32 - (sizeof (sigset_t) / sizeof (int))];
+        /* Last for extensibility.  Eight byte aligned because some
+           coprocessors require eight byte alignment.  */
+        unsigned long     uc_regspace[128] __attribute__((__aligned__(8)));
 };
 
+#ifdef __KERNEL__
+
+/*
+ * Coprocessor save state.  The magic values and specific
+ * coprocessor's layouts are part of the userspace ABI.  Each one of
+ * these should be a multiple of eight bytes and aligned to eight
+ * bytes, to prevent unpredictable padding in the signal frame.
+ */
+
+#ifdef CONFIG_IWMMXT
+/* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */
+#define IWMMXT_MAGIC            0x12ef842a
+#define IWMMXT_STORAGE_SIZE     (IWMMXT_SIZE + 8)
+
+struct iwmmxt_sigframe {
+        unsigned long   magic;
+        unsigned long   size;
+        struct iwmmxt_struct storage;
+} __attribute__((__aligned__(8)));
+#endif /* CONFIG_IWMMXT */
+
+#ifdef CONFIG_VFP
+#if __LINUX_ARM_ARCH__ < 6
+/* For ARM pre-v6, we use fstmiax and fldmiax.  This adds one extra
+ * word after the registers, and a word of padding at the end for
+ * alignment.  */
+#define VFP_MAGIC               0x56465001
+#define VFP_STORAGE_SIZE        152
+#else
+#define VFP_MAGIC               0x56465002
+#define VFP_STORAGE_SIZE        144
+#endif
+
+struct vfp_sigframe
+{
+        unsigned long           magic;
+        unsigned long           size;
+        union vfp_state         storage;
+};
+#endif /* CONFIG_VFP */
+
+/*
+ * Auxiliary signal frame.  This saves stuff like FP state.
+ * The layout of this structure is not part of the user ABI,
+ * because the config options aren't.  uc_regspace is really
+ * one of these.
+ */
+struct aux_sigframe {
+#ifdef CONFIG_IWMMXT
+        struct iwmmxt_sigframe  iwmmxt;
+#endif
+#if 0 && defined CONFIG_VFP /* Not yet saved.  */
+        struct vfp_sigframe     vfp;
+#endif
+        /* Something that isn't a valid magic number for any coprocessor.  */
+        unsigned long           end_magic;
+} __attribute__((__aligned__(8)));
+
+#endif
+
 #endif /* !_ASMARM_UCONTEXT_H */