Merge branch 'x86-tracehook' of git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-utrace into x86/tracehook

7 files changed, 248 insertions, 66 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b6fa2877b173..f463a8a3b21f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -30,6 +30,7 @@ config X86
         select HAVE_FTRACE
         select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
         select HAVE_ARCH_KGDB if !X86_VOYAGER
+        select HAVE_ARCH_TRACEHOOK
         select HAVE_EFFICIENT_UNALIGNED_ACCESS
 
 config ARCH_DEFCONFIG
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index e37dccce85db..19a7d2c40560 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -14,6 +14,7 @@
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/regset.h>
+#include <linux/tracehook.h>
 #include <linux/user.h>
 #include <linux/elf.h>
 #include <linux/security.h>
@@ -1375,30 +1376,6 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
         force_sig_info(SIGTRAP, &info, tsk);
 }
 
-static void syscall_trace(struct pt_regs *regs)
-{
-        if (!(current->ptrace & PT_PTRACED))
-                return;
-
-#if 0
-        printk("trace %s ip %lx sp %lx ax %d origrax %d caller %lx tiflags %x ptrace %x\n",
-               current->comm,
-               regs->ip, regs->sp, regs->ax, regs->orig_ax, __builtin_return_address(0),
-               current_thread_info()->flags, current->ptrace);
-#endif
-
-        ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-                                ? 0x80 : 0));
-        /*
-         * this isn't the same as continuing with a signal, but it will do
-         * for normal use.  strace only continues with a signal if the
-         * stopping signal is not SIGTRAP.  -brl
-         */
-        if (current->exit_code) {
-                send_sig(current->exit_code, current, 1);
-                current->exit_code = 0;
-        }
-}
 
 #ifdef CONFIG_X86_32
 # define IS_IA32        1
@@ -1432,8 +1409,9 @@ asmregparm long syscall_trace_enter(struct pt_regs *regs)
         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
                 ret = -1L;
 
-        if (ret || test_thread_flag(TIF_SYSCALL_TRACE))
-                syscall_trace(regs);
+        if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
+            tracehook_report_syscall_entry(regs))
+                ret = -1L;
 
         if (unlikely(current->audit_context)) {
                 if (IS_IA32)
@@ -1459,7 +1437,7 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs)
                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
 
         if (test_thread_flag(TIF_SYSCALL_TRACE))
-                syscall_trace(regs);
+                tracehook_report_syscall_exit(regs, 0);
 
         /*
          * If TIF_SYSCALL_EMU is set, we only get here because of
@@ -1475,6 +1453,6 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs)
          * system call instruction.
          */
         if (test_thread_flag(TIF_SINGLESTEP) &&
-            (current->ptrace & PT_PTRACED))
+            tracehook_consider_fatal_signal(current, SIGTRAP, SIG_DFL))
                 send_sigtrap(current, regs, 0);
 }
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 6fb5bcdd8933..4445d26efd47 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -17,6 +17,7 @@
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
+#include <linux/tracehook.h>
 #include <linux/elf.h>
 #include <linux/smp.h>
 #include <linux/mm.h>
@@ -558,8 +559,6 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
          * handler too.
          */
         regs->flags &= ~X86_EFLAGS_TF;
-        if (test_thread_flag(TIF_SINGLESTEP))
-                ptrace_notify(SIGTRAP);
 
         spin_lock_irq(&current->sighand->siglock);
         sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
@@ -568,6 +567,9 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
         recalc_sigpending();
         spin_unlock_irq(&current->sighand->siglock);
 
+        tracehook_signal_handler(sig, info, ka, regs,
+                                 test_thread_flag(TIF_SINGLESTEP));
+
         return 0;
 }
 
@@ -661,5 +663,10 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
         if (thread_info_flags & _TIF_SIGPENDING)
                 do_signal(regs);
 
+        if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+                clear_thread_flag(TIF_NOTIFY_RESUME);
+                tracehook_notify_resume(regs);
+        }
+
         clear_thread_flag(TIF_IRET);
 }
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index b45ef8ddd651..d01e3f6ef26d 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -15,6 +15,7 @@
 #include <linux/errno.h>
 #include <linux/wait.h>
 #include <linux/ptrace.h>
+#include <linux/tracehook.h>
 #include <linux/unistd.h>
 #include <linux/stddef.h>
 #include <linux/personality.h>
@@ -26,6 +27,7 @@
 #include <asm/proto.h>
 #include <asm/ia32_unistd.h>
 #include <asm/mce.h>
+#include <asm/syscall.h>
 #include "sigframe.h"
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
@@ -346,35 +348,6 @@ give_sigsegv:
 }
 
 /*
- * Return -1L or the syscall number that @regs is executing.
- */
-static long current_syscall(struct pt_regs *regs)
-{
-        /*
-         * We always sign-extend a -1 value being set here,
-         * so this is always either -1L or a syscall number.
-         */
-        return regs->orig_ax;
-}
-
-/*
- * Return a value that is -EFOO if the system call in @regs->orig_ax
- * returned an error.  This only works for @regs from @current.
- */
-static long current_syscall_ret(struct pt_regs *regs)
-{
-#ifdef CONFIG_IA32_EMULATION
-        if (test_thread_flag(TIF_IA32))
-                /*
-                 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
-                 * and will match correctly in comparisons.
-                 */
-                return (int) regs->ax;
-#endif
-        return regs->ax;
-}
-
-/*
  * OK, we're invoking a handler
  */     
 
@@ -385,9 +358,9 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
         int ret;
 
         /* Are we from a system call? */
-        if (current_syscall(regs) >= 0) {
+        if (syscall_get_nr(current, regs) >= 0) {
                 /* If so, check system call restarting.. */
-                switch (current_syscall_ret(regs)) {
+                switch (syscall_get_error(current, regs)) {
                 case -ERESTART_RESTARTBLOCK:
                 case -ERESTARTNOHAND:
                         regs->ax = -EINTR;
@@ -444,8 +417,6 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
                  * handler too.
                  */
                 regs->flags &= ~X86_EFLAGS_TF;
-                if (test_thread_flag(TIF_SINGLESTEP))
-                        ptrace_notify(SIGTRAP);
 
                 spin_lock_irq(&current->sighand->siglock);
                 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
@@ -453,6 +424,9 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
                         sigaddset(&current->blocked,sig);
                 recalc_sigpending();
                 spin_unlock_irq(&current->sighand->siglock);
+
+                tracehook_signal_handler(sig, info, ka, regs,
+                                         test_thread_flag(TIF_SINGLESTEP));
         }
 
         return ret;
@@ -509,9 +483,9 @@ static void do_signal(struct pt_regs *regs)
         }
 
         /* Did we come from a system call? */
-        if (current_syscall(regs) >= 0) {
+        if (syscall_get_nr(current, regs) >= 0) {
                 /* Restart the system call - no handlers present */
-                switch (current_syscall_ret(regs)) {
+                switch (syscall_get_error(current, regs)) {
                 case -ERESTARTNOHAND:
                 case -ERESTARTSYS:
                 case -ERESTARTNOINTR:
@@ -549,6 +523,11 @@ void do_notify_resume(struct pt_regs *regs, void *unused,
         /* deal with pending signal delivery */
         if (thread_info_flags & _TIF_SIGPENDING)
                 do_signal(regs);
+
+        if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+                clear_thread_flag(TIF_NOTIFY_RESUME);
+                tracehook_notify_resume(regs);
+        }
 }
 
 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
diff --git a/include/asm-x86/ptrace.h b/include/asm-x86/ptrace.h
index 8a71db803da6..91a77f5c4678 100644
--- a/include/asm-x86/ptrace.h
+++ b/include/asm-x86/ptrace.h
@@ -213,6 +213,11 @@ static inline unsigned long frame_pointer(struct pt_regs *regs)
         return regs->bp;
 }
 
+static inline unsigned long user_stack_pointer(struct pt_regs *regs)
+{
+        return regs->sp;
+}
+
 /*
  * These are defined as per linux/ptrace.h, which see.
  */
diff --git a/include/asm-x86/syscall.h b/include/asm-x86/syscall.h
new file mode 100644
index 000000000000..6f293892895a
--- /dev/null
+++ b/include/asm-x86/syscall.h
@@ -0,0 +1,210 @@
+/*
+ * Access to user system call parameters and results
+ *
+ * Copyright (C) 2008 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ *
+ * See asm-generic/syscall.h for descriptions of what we must do here.
+ */
+
+#ifndef _ASM_SYSCALL_H
+#define _ASM_SYSCALL_H  1
+
+#include <linux/sched.h>
+
+static inline long syscall_get_nr(struct task_struct *task,
+                                  struct pt_regs *regs)
+{
+        /*
+         * We always sign-extend a -1 value being set here,
+         * so this is always either -1L or a syscall number.
+         */
+        return regs->orig_ax;
+}
+
+static inline void syscall_rollback(struct task_struct *task,
+                                    struct pt_regs *regs)
+{
+        regs->ax = regs->orig_ax;
+}
+
+static inline long syscall_get_error(struct task_struct *task,
+                                     struct pt_regs *regs)
+{
+        unsigned long error = regs->ax;
+#ifdef CONFIG_IA32_EMULATION
+        /*
+         * TS_COMPAT is set for 32-bit syscall entries and then
+         * remains set until we return to user mode.
+         */
+        if (task_thread_info(task)->status & TS_COMPAT)
+                /*
+                 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
+                 * and will match correctly in comparisons.
+                 */
+                error = (long) (int) error;
+#endif
+        return error >= -4095L ? error : 0;
+}
+
+static inline long syscall_get_return_value(struct task_struct *task,
+                                            struct pt_regs *regs)
+{
+        return regs->ax;
+}
+
+static inline void syscall_set_return_value(struct task_struct *task,
+                                            struct pt_regs *regs,
+                                            int error, long val)
+{
+        regs->ax = (long) error ?: val;
+}
+
+#ifdef CONFIG_X86_32
+
+static inline void syscall_get_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         unsigned long *args)
+{
+        BUG_ON(i + n > 6);
+        memcpy(args, &regs->bx + i, n * sizeof(args[0]));
+}
+
+static inline void syscall_set_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         const unsigned long *args)
+{
+        BUG_ON(i + n > 6);
+        memcpy(&regs->bx + i, args, n * sizeof(args[0]));
+}
+
+#else    /* CONFIG_X86_64 */
+
+static inline void syscall_get_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         unsigned long *args)
+{
+# ifdef CONFIG_IA32_EMULATION
+        if (task_thread_info(task)->status & TS_COMPAT)
+                switch (i + n) {
+                case 6:
+                        if (!n--) break;
+                        *args++ = regs->bp;
+                case 5:
+                        if (!n--) break;
+                        *args++ = regs->di;
+                case 4:
+                        if (!n--) break;
+                        *args++ = regs->si;
+                case 3:
+                        if (!n--) break;
+                        *args++ = regs->dx;
+                case 2:
+                        if (!n--) break;
+                        *args++ = regs->cx;
+                case 1:
+                        if (!n--) break;
+                        *args++ = regs->bx;
+                case 0:
+                        if (!n--) break;
+                default:
+                        BUG();
+                        break;
+                }
+        else
+# endif
+                switch (i + n) {
+                case 6:
+                        if (!n--) break;
+                        *args++ = regs->r9;
+                case 5:
+                        if (!n--) break;
+                        *args++ = regs->r8;
+                case 4:
+                        if (!n--) break;
+                        *args++ = regs->r10;
+                case 3:
+                        if (!n--) break;
+                        *args++ = regs->dx;
+                case 2:
+                        if (!n--) break;
+                        *args++ = regs->si;
+                case 1:
+                        if (!n--) break;
+                        *args++ = regs->di;
+                case 0:
+                        if (!n--) break;
+                default:
+                        BUG();
+                        break;
+                }
+}
+
+static inline void syscall_set_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         const unsigned long *args)
+{
+# ifdef CONFIG_IA32_EMULATION
+        if (task_thread_info(task)->status & TS_COMPAT)
+                switch (i + n) {
+                case 6:
+                        if (!n--) break;
+                        regs->bp = *args++;
+                case 5:
+                        if (!n--) break;
+                        regs->di = *args++;
+                case 4:
+                        if (!n--) break;
+                        regs->si = *args++;
+                case 3:
+                        if (!n--) break;
+                        regs->dx = *args++;
+                case 2:
+                        if (!n--) break;
+                        regs->cx = *args++;
+                case 1:
+                        if (!n--) break;
+                        regs->bx = *args++;
+                case 0:
+                        if (!n--) break;
+                default:
+                        BUG();
+                }
+        else
+# endif
+                switch (i + n) {
+                case 6:
+                        if (!n--) break;
+                        regs->r9 = *args++;
+                case 5:
+                        if (!n--) break;
+                        regs->r8 = *args++;
+                case 4:
+                        if (!n--) break;
+                        regs->r10 = *args++;
+                case 3:
+                        if (!n--) break;
+                        regs->dx = *args++;
+                case 2:
+                        if (!n--) break;
+                        regs->si = *args++;
+                case 1:
+                        if (!n--) break;
+                        regs->di = *args++;
+                case 0:
+                        if (!n--) break;
+                default:
+                        BUG();
+                }
+}
+
+#endif  /* CONFIG_X86_32 */
+
+#endif  /* _ASM_SYSCALL_H */
diff --git a/include/asm-x86/thread_info.h b/include/asm-x86/thread_info.h
index da0a675adf94..4cd5b7bdc8cc 100644
--- a/include/asm-x86/thread_info.h
+++ b/include/asm-x86/thread_info.h
@@ -71,6 +71,7 @@ struct thread_info {
  * Warning: layout of LSW is hardcoded in entry.S
  */
 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
+#define TIF_NOTIFY_RESUME       1       /* callback before returning to user */
 #define TIF_SIGPENDING          2       /* signal pending */
 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 #define TIF_SINGLESTEP          4       /* reenable singlestep on user return*/
@@ -93,6 +94,7 @@ struct thread_info {
 #define TIF_BTS_TRACE_TS        27      /* record scheduling event timestamps */
 
 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
+#define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 #define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
@@ -133,7 +135,7 @@ struct thread_info {
 
 /* Only used for 64 bit */
 #define _TIF_DO_NOTIFY_MASK                                             \
-        (_TIF_SIGPENDING|_TIF_MCE_NOTIFY)
+        (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)
 
 /* flags to check in __switch_to() */
 #define _TIF_WORK_CTXSW                                                 \