Merge branch 'x86/tracehook' into x86-v28-for-linus-phase1

Conflicts:
	arch/x86/kernel/signal_64.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>

7 files changed, 249 insertions, 66 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ed92864..ebfd7ff 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -29,6 +29,7 @@ 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_GENERIC_DMA_COHERENT if X86_32
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
 
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index d00e756..e375b65 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>
@@ -1469,30 +1470,6 @@ 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
@@ -1526,8 +1503,9 @@ 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)
@@ -1553,7 +1531,7 @@ 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
@@ -1569,6 +1547,6 @@ 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 0c727f6..2a2435d 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>
@@ -559,8 +560,6 @@ 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);
@@ -569,6 +568,9 @@ 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;
 }
 
@@ -662,5 +664,10 @@ 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 2f14640..4d32487 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 <asm/syscalls.h>
 #include "sigframe.h"
 
@@ -356,35 +358,6 @@ 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
  */	
 
@@ -395,9 +368,9 @@ 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;
@@ -454,8 +427,6 @@ 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);
@@ -463,6 +434,9 @@ 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;
@@ -519,9 +493,9 @@ 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:
@@ -559,6 +533,11 @@ 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 33a034b..d64a610 100644
--- a/include/asm-x86/ptrace.h
+++ b/include/asm-x86/ptrace.h
@@ -250,6 +250,11 @@ 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 0000000..04c47dc
--- /dev/null
+++ b/include/asm-x86/syscall.h
@@ -0,0 +1,211 @@
+/*
+ * 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>
+#include <linux/err.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 IS_ERR_VALUE(error) ? 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 e64be88..4db0066 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							\