uml: tidy fault code

Tidying in preparation for the segfault register dumping patch which follows.

void * pointers are changed to union uml_pt_regs *.  This makes the types
match reality, except in arch_fixup, which is changed to operate on a union
uml_pt_regs.  This fixes a bug in the call from segv_handler, which passes a
union uml_pt_regs, to segv, which expects to pass a struct sigcontext to
arch_fixup.

Whitespace and other style fixes.

There's also a errno printk fix.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

8 files changed, 63 insertions, 84 deletions

diff --git a/arch/um/include/arch.h b/arch/um/include/arch.h
index 8e11dd7c1adb..10ad52daa8c5 100644
--- a/arch/um/include/arch.h
+++ b/arch/um/include/arch.h
@@ -9,7 +9,7 @@
 #include "sysdep/ptrace.h"
 
 extern void arch_check_bugs(void);
-extern int arch_fixup(unsigned long address, void *sc_ptr);
+extern int arch_fixup(unsigned long address, union uml_pt_regs *regs);
 extern int arch_handle_signal(int sig, union uml_pt_regs *regs);
 
 #endif
diff --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h
index ae434a9b400d..092a2841556f 100644
--- a/arch/um/include/kern_util.h
+++ b/arch/um/include/kern_util.h
@@ -44,7 +44,7 @@ extern unsigned long alloc_stack(int order, int atomic);
 extern int do_signal(void);
 extern int is_stack_fault(unsigned long sp);
 extern unsigned long segv(struct faultinfo fi, unsigned long ip,
-                          int is_user, void *sc);
+                          int is_user, union uml_pt_regs *regs);
 extern int handle_page_fault(unsigned long address, unsigned long ip,
                              int is_write, int is_user, int *code_out);
 extern void syscall_ready(void);
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 2de81d4d9b57..c3e62e634c0a 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -72,8 +72,8 @@ good_area:
                 goto out;
 
         /* Don't require VM_READ|VM_EXEC for write faults! */
-        if(!is_write && !(vma->vm_flags & (VM_READ | VM_EXEC)))
-                goto out;
+        if(!is_write && !(vma->vm_flags & (VM_READ | VM_EXEC)))
+                goto out;
 
         do {
 survive:
@@ -157,18 +157,19 @@ static void segv_handler(int sig, union uml_pt_regs *regs)
  * the info in the regs. A pointer to the info then would
  * give us bad data!
  */
-unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
+unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
+                   union uml_pt_regs *regs)
 {
         struct siginfo si;
         void *catcher;
         int err;
-        int is_write = FAULT_WRITE(fi);
-        unsigned long address = FAULT_ADDRESS(fi);
+        int is_write = FAULT_WRITE(fi);
+        unsigned long address = FAULT_ADDRESS(fi);
 
-        if(!is_user && (address >= start_vm) && (address < end_vm)){
-                flush_tlb_kernel_vm();
-                return(0);
-        }
+        if(!is_user && (address >= start_vm) && (address < end_vm)){
+                flush_tlb_kernel_vm();
+                return 0;
+        }
         else if(current->mm == NULL)
                 panic("Segfault with no mm");
 
@@ -183,17 +184,17 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
 
         catcher = current->thread.fault_catcher;
         if(!err)
-                return(0);
+                return 0;
         else if(catcher != NULL){
                 current->thread.fault_addr = (void *) address;
                 do_longjmp(catcher, 1);
         }
         else if(current->thread.fault_addr != NULL)
                 panic("fault_addr set but no fault catcher");
-        else if(!is_user && arch_fixup(ip, sc))
-                return(0);
+        else if(!is_user && arch_fixup(ip, regs))
+                return 0;
 
-        if(!is_user)
+        if(!is_user)
                 panic("Kernel mode fault at addr 0x%lx, ip 0x%lx",
                       address, ip);
 
@@ -202,7 +203,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
                 si.si_errno = 0;
                 si.si_code = BUS_ADRERR;
                 si.si_addr = (void __user *)address;
-                current->thread.arch.faultinfo = fi;
+                current->thread.arch.faultinfo = fi;
                 force_sig_info(SIGBUS, &si, current);
         } else if (err == -ENOMEM) {
                 printk("VM: killing process %s\n", current->comm);
@@ -211,10 +212,10 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
                 BUG_ON(err != -EFAULT);
                 si.si_signo = SIGSEGV;
                 si.si_addr = (void __user *) address;
-                current->thread.arch.faultinfo = fi;
+                current->thread.arch.faultinfo = fi;
                 force_sig_info(SIGSEGV, &si, current);
         }
-        return(0);
+        return 0;
 }
 
 void relay_signal(int sig, union uml_pt_regs *regs)
@@ -229,7 +230,7 @@ void relay_signal(int sig, union uml_pt_regs *regs)
                 panic("Kernel mode signal %d", sig);
         }
 
-        current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
+        current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
         force_sig(sig, current);
 }
 
diff --git a/arch/um/os-Linux/skas/trap.c b/arch/um/os-Linux/skas/trap.c
index f104427d2caf..6a20d08caf91 100644
--- a/arch/um/os-Linux/skas/trap.c
+++ b/arch/um/os-Linux/skas/trap.c
@@ -18,10 +18,9 @@
 void sig_handler_common_skas(int sig, void *sc_ptr)
 {
         struct sigcontext *sc = sc_ptr;
-        struct skas_regs *r;
+        union uml_pt_regs *r;
         void (*handler)(int, union uml_pt_regs *);
-        int save_errno = errno;
-        int save_user;
+        int save_user, save_errno = errno;
 
         /* This is done because to allow SIGSEGV to be delivered inside a SEGV
          * handler.  This can happen in copy_user, and if SEGV is disabled,
@@ -31,13 +30,13 @@ void sig_handler_common_skas(int sig, void *sc_ptr)
         if(sig == SIGSEGV)
                 change_sig(SIGSEGV, 1);
 
-        r = &TASK_REGS(get_current())->skas;
-        save_user = r->is_user;
-        r->is_user = 0;
+        r = TASK_REGS(get_current());
+        save_user = r->skas.is_user;
+        r->skas.is_user = 0;
         if ( sig == SIGFPE || sig == SIGSEGV ||
              sig == SIGBUS || sig == SIGILL ||
              sig == SIGTRAP ) {
-                GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
+                GET_FAULTINFO_FROM_SC(r->skas.faultinfo, sc);
         }
 
         change_sig(SIGUSR1, 1);
@@ -49,10 +48,10 @@ void sig_handler_common_skas(int sig, void *sc_ptr)
             sig != SIGVTALRM && sig != SIGALRM)
                 unblock_signals();
 
-        handler(sig, (union uml_pt_regs *) r);
+        handler(sig, r);
 
         errno = save_errno;
-        r->is_user = save_user;
+        r->skas.is_user = save_user;
 }
 
 extern int ptrace_faultinfo;
diff --git a/arch/um/sys-i386/fault.c b/arch/um/sys-i386/fault.c
index d0bbcdfdb53f..745b4fd49e9f 100644
--- a/arch/um/sys-i386/fault.c
+++ b/arch/um/sys-i386/fault.c
@@ -3,9 +3,7 @@
  * Licensed under the GPL
  */
 
-#include <signal.h>
 #include "sysdep/ptrace.h"
-#include "sysdep/sigcontext.h"
 
 /* These two are from asm-um/uaccess.h and linux/module.h, check them. */
 struct exception_table_entry
@@ -17,26 +15,14 @@ struct exception_table_entry
 const struct exception_table_entry *search_exception_tables(unsigned long add);
 
 /* Compare this to arch/i386/mm/extable.c:fixup_exception() */
-int arch_fixup(unsigned long address, void *sc_ptr)
+int arch_fixup(unsigned long address, union uml_pt_regs *regs)
 {
-        struct sigcontext *sc = sc_ptr;
         const struct exception_table_entry *fixup;
 
         fixup = search_exception_tables(address);
         if(fixup != 0){
-                sc->eip = fixup->fixup;
+                UPT_IP(regs) = fixup->fixup;
                 return(1);
         }
         return(0);
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c
index 3f6acd667717..42ecf8e8ad08 100644
--- a/arch/um/sys-i386/signal.c
+++ b/arch/um/sys-i386/signal.c
@@ -28,7 +28,7 @@ static int copy_sc_from_user_skas(struct pt_regs *regs,
         err = copy_from_user(&sc, from, sizeof(sc));
         err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs));
         if(err)
-                return(err);
+                return err;
 
         REGS_GS(regs->regs.skas.regs) = sc.gs;
         REGS_FS(regs->regs.skas.regs) = sc.fs;
@@ -50,11 +50,11 @@ static int copy_sc_from_user_skas(struct pt_regs *regs,
         err = restore_fp_registers(userspace_pid[0], fpregs);
         if(err < 0){
                 printk("copy_sc_from_user_skas - PTRACE_SETFPREGS failed, "
-                       "errno = %d\n", err);
-                return(1);
+                       "errno = %d\n", -err);
+                return err;
         }
 
-        return(0);
+        return 0;
 }
 
 int copy_sc_to_user_skas(struct sigcontext __user *to, struct _fpstate __user *to_fp,
@@ -90,16 +90,16 @@ int copy_sc_to_user_skas(struct sigcontext __user *to, struct _fpstate __user *t
         if(err < 0){
                 printk("copy_sc_to_user_skas - PTRACE_GETFPREGS failed, "
                        "errno = %d\n", err);
-                return(1);
+                return 1;
         }
         to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
         sc.fpstate = to_fp;
 
         if(err)
-                return(err);
+                return err;
 
-        return(copy_to_user(to, &sc, sizeof(sc)) ||
-               copy_to_user(to_fp, fpregs, sizeof(fpregs)));
+        return copy_to_user(to, &sc, sizeof(sc)) ||
+               copy_to_user(to_fp, fpregs, sizeof(fpregs));
 }
 #endif
 
@@ -129,7 +129,7 @@ int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext __user *from,
         to->fpstate = to_fp;
         if(to_fp != NULL)
                 err |= copy_from_user(to_fp, from_fp, fpsize);
-        return(err);
+        return err;
 }
 
 int copy_sc_to_user_tt(struct sigcontext __user *to, struct _fpstate __user *fp,
@@ -164,15 +164,15 @@ static int copy_sc_from_user(struct pt_regs *to, void __user *from)
         ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
                                                sizeof(struct _fpstate)),
                           copy_sc_from_user_skas(to, from));
-        return(ret);
+        return ret;
 }
 
 static int copy_sc_to_user(struct sigcontext __user *to, struct _fpstate __user *fp,
                            struct pt_regs *from, unsigned long sp)
 {
-        return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
+        return CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
                                               sizeof(*fp), sp),
-                           copy_sc_to_user_skas(to, fp, from, sp)));
+                           copy_sc_to_user_skas(to, fp, from, sp));
 }
 
 static int copy_ucontext_to_user(struct ucontext __user *uc, struct _fpstate __user *fp,
@@ -185,7 +185,7 @@ static int copy_ucontext_to_user(struct ucontext __user *uc, struct _fpstate __u
         err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
         err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, sp);
         err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
-        return(err);
+        return err;
 }
 
 struct sigframe
@@ -359,7 +359,7 @@ long sys_sigreturn(struct pt_regs regs)
 
         /* Avoid ERESTART handling */
         PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
-        return(PT_REGS_SYSCALL_RET(&current->thread.regs));
+        return PT_REGS_SYSCALL_RET(&current->thread.regs);
 
  segfault:
         force_sig(SIGSEGV, current);
@@ -389,20 +389,9 @@ long sys_rt_sigreturn(struct pt_regs regs)
 
         /* Avoid ERESTART handling */
         PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
-        return(PT_REGS_SYSCALL_RET(&current->thread.regs));
+        return PT_REGS_SYSCALL_RET(&current->thread.regs);
 
  segfault:
         force_sig(SIGSEGV, current);
         return 0;
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/sys-x86_64/fault.c b/arch/um/sys-x86_64/fault.c
index cee1513c5c31..4636b1465b6c 100644
--- a/arch/um/sys-x86_64/fault.c
+++ b/arch/um/sys-x86_64/fault.c
@@ -4,20 +4,24 @@
  * Licensed under the GPL
  */
 
-#include "user.h"
+#include "sysdep/ptrace.h"
 
-int arch_fixup(unsigned long address, void *sc_ptr)
+/* These two are from asm-um/uaccess.h and linux/module.h, check them. */
+struct exception_table_entry
 {
-        /* XXX search_exception_tables() */
+        unsigned long insn;
+        unsigned long fixup;
+};
+
+const struct exception_table_entry *search_exception_tables(unsigned long add);
+int arch_fixup(unsigned long address, union uml_pt_regs *regs)
+{
+        const struct exception_table_entry *fixup;
+
+        fixup = search_exception_tables(address);
+        if(fixup != 0){
+                UPT_IP(regs) = fixup->fixup;
+                return(1);
+        }
         return(0);
 }
-
-/* Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/sys-x86_64/signal.c b/arch/um/sys-x86_64/signal.c
index af2f017617b4..068006213598 100644
--- a/arch/um/sys-x86_64/signal.c
+++ b/arch/um/sys-x86_64/signal.c
@@ -51,7 +51,7 @@ static int copy_sc_from_user_skas(struct pt_regs *regs,
 
 #undef GETREG
 
-       return(err);
+       return err;
 }
 
 int copy_sc_to_user_skas(struct sigcontext __user *to,