1 files changed, 62 insertions, 37 deletions

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index e33870ff0ac..0c27ed6f3f2 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -23,11 +23,16 @@
 #include <linux/perf_event.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/regset.h>
+#include <linux/audit.h>
+#include <linux/tracehook.h>
+#include <linux/unistd.h>
 
 #include <asm/pgtable.h>
-#include <asm/system.h>
 #include <asm/traps.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
 #define REG_PC	15
 #define REG_PSR	16
 /*
@@ -256,7 +261,7 @@ static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 {
 	unsigned long tmp;
 
-	if (off & 3 || off >= sizeof(struct user))
+	if (off & 3)
 		return -EIO;
 
 	tmp = 0;
@@ -268,6 +273,8 @@ static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 		tmp = tsk->mm->end_code;
 	else if (off < sizeof(struct pt_regs))
 		tmp = get_user_reg(tsk, off >> 2);
+	else if (off >= sizeof(struct user))
+		return -EIO;
 
 	return put_user(tmp, ret);
 }
@@ -842,7 +849,7 @@ long arch_ptrace(struct task_struct *child, long request,
 #endif
 
 		case PTRACE_GET_THREAD_AREA:
-			ret = put_user(task_thread_info(child)->tp_value,
+			ret = put_user(task_thread_info(child)->tp_value[0],
 				       datap);
 			break;
 
@@ -879,20 +886,12 @@ long arch_ptrace(struct task_struct *child, long request,
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 		case PTRACE_GETHBPREGS:
-			if (ptrace_get_breakpoints(child) < 0)
-				return -ESRCH;
-
 			ret = ptrace_gethbpregs(child, addr,
 						(unsigned long __user *)data);
-			ptrace_put_breakpoints(child);
 			break;
 		case PTRACE_SETHBPREGS:
-			if (ptrace_get_breakpoints(child) < 0)
-				return -ESRCH;
-
 			ret = ptrace_sethbpregs(child, addr,
 						(unsigned long __user *)data);
-			ptrace_put_breakpoints(child);
 			break;
 #endif
 
@@ -904,44 +903,70 @@ long arch_ptrace(struct task_struct *child, long request,
 	return ret;
 }
 
-asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
+enum ptrace_syscall_dir {
+	PTRACE_SYSCALL_ENTER = 0,
+	PTRACE_SYSCALL_EXIT,
+};
+
+static void tracehook_report_syscall(struct pt_regs *regs,
+				    enum ptrace_syscall_dir dir)
 {
 	unsigned long ip;
 
 	/*
-	 * Save IP.  IP is used to denote syscall entry/exit:
-	 *  IP = 0 -> entry, = 1 -> exit
+	 * IP is used to denote syscall entry/exit:
+	 * IP = 0 -> entry, =1 -> exit
 	 */
 	ip = regs->ARM_ip;
-	regs->ARM_ip = why;
+	regs->ARM_ip = dir;
 
-	if (!ip)
-		audit_syscall_exit(regs);
-	else
-		audit_syscall_entry(AUDIT_ARCH_ARMEB, scno, regs->ARM_r0,
-				    regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
+	if (dir == PTRACE_SYSCALL_EXIT)
+		tracehook_report_syscall_exit(regs, 0);
+	else if (tracehook_report_syscall_entry(regs))
+		current_thread_info()->syscall = -1;
 
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return scno;
-	if (!(current->ptrace & PT_PTRACED))
-		return scno;
+	regs->ARM_ip = ip;
+}
 
+asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
+{
 	current_thread_info()->syscall = scno;
 
-	/* the 0x80 provides a way for the tracing parent to distinguish
-	   between a syscall stop and SIGTRAP delivery */
-	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-				 ? 0x80 : 0));
+	/* Do the secure computing check first; failures should be fast. */
+	if (secure_computing(scno) == -1)
+		return -1;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+
+	scno = current_thread_info()->syscall;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_enter(regs, scno);
+
+	audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1,
+			    regs->ARM_r2, regs->ARM_r3);
+
+	return scno;
+}
+
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
+{
 	/*
-	 * 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
+	 * Audit the syscall before anything else, as a debugger may
+	 * come in and change the current registers.
 	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
-	}
-	regs->ARM_ip = ip;
+	audit_syscall_exit(regs);
+
+	/*
+	 * Note that we haven't updated the ->syscall field for the
+	 * current thread. This isn't a problem because it will have
+	 * been set on syscall entry and there hasn't been an opportunity
+	 * for a PTRACE_SET_SYSCALL since then.
+	 */
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_exit(regs, regs_return_value(regs));
 
-	return current_thread_info()->syscall;
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
 }