x86/entry: Move C entry and exit code to arch/x86/entry/common.c

The entry and exit C helpers were confusingly scattered between
ptrace.c and signal.c, even though they aren't specific to
ptrace or signal handling.  Move them together in a new file.

This change just moves code around.  It doesn't change anything.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/324d686821266544d8572423cc281f961da445f4.1435952415.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 1 insertions, 201 deletions

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 7155957b3c25..558f50edebca 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -37,12 +37,10 @@
 #include <asm/proto.h>
 #include <asm/hw_breakpoint.h>
 #include <asm/traps.h>
+#include <asm/syscall.h>
 
 #include "tls.h"
 
-#define CREATE_TRACE_POINTS
-#include <trace/events/syscalls.h>
-
 enum x86_regset {
 	REGSET_GENERAL,
 	REGSET_FP,
@@ -1444,201 +1442,3 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
 	/* Send us the fake SIGTRAP */
 	force_sig_info(SIGTRAP, &info, tsk);
 }
-
-static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch)
-{
-#ifdef CONFIG_X86_64
-	if (arch == AUDIT_ARCH_X86_64) {
-		audit_syscall_entry(regs->orig_ax, regs->di,
-				    regs->si, regs->dx, regs->r10);
-	} else
-#endif
-	{
-		audit_syscall_entry(regs->orig_ax, regs->bx,
-				    regs->cx, regs->dx, regs->si);
-	}
-}
-
-/*
- * We can return 0 to resume the syscall or anything else to go to phase
- * 2.  If we resume the syscall, we need to put something appropriate in
- * regs->orig_ax.
- *
- * NB: We don't have full pt_regs here, but regs->orig_ax and regs->ax
- * are fully functional.
- *
- * For phase 2's benefit, our return value is:
- * 0:			resume the syscall
- * 1:			go to phase 2; no seccomp phase 2 needed
- * anything else:	go to phase 2; pass return value to seccomp
- */
-unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch)
-{
-	unsigned long ret = 0;
-	u32 work;
-
-	BUG_ON(regs != task_pt_regs(current));
-
-	work = ACCESS_ONCE(current_thread_info()->flags) &
-		_TIF_WORK_SYSCALL_ENTRY;
-
-	/*
-	 * If TIF_NOHZ is set, we are required to call user_exit() before
-	 * doing anything that could touch RCU.
-	 */
-	if (work & _TIF_NOHZ) {
-		user_exit();
-		work &= ~_TIF_NOHZ;
-	}
-
-#ifdef CONFIG_SECCOMP
-	/*
-	 * Do seccomp first -- it should minimize exposure of other
-	 * code, and keeping seccomp fast is probably more valuable
-	 * than the rest of this.
-	 */
-	if (work & _TIF_SECCOMP) {
-		struct seccomp_data sd;
-
-		sd.arch = arch;
-		sd.nr = regs->orig_ax;
-		sd.instruction_pointer = regs->ip;
-#ifdef CONFIG_X86_64
-		if (arch == AUDIT_ARCH_X86_64) {
-			sd.args[0] = regs->di;
-			sd.args[1] = regs->si;
-			sd.args[2] = regs->dx;
-			sd.args[3] = regs->r10;
-			sd.args[4] = regs->r8;
-			sd.args[5] = regs->r9;
-		} else
-#endif
-		{
-			sd.args[0] = regs->bx;
-			sd.args[1] = regs->cx;
-			sd.args[2] = regs->dx;
-			sd.args[3] = regs->si;
-			sd.args[4] = regs->di;
-			sd.args[5] = regs->bp;
-		}
-
-		BUILD_BUG_ON(SECCOMP_PHASE1_OK != 0);
-		BUILD_BUG_ON(SECCOMP_PHASE1_SKIP != 1);
-
-		ret = seccomp_phase1(&sd);
-		if (ret == SECCOMP_PHASE1_SKIP) {
-			regs->orig_ax = -1;
-			ret = 0;
-		} else if (ret != SECCOMP_PHASE1_OK) {
-			return ret;  /* Go directly to phase 2 */
-		}
-
-		work &= ~_TIF_SECCOMP;
-	}
-#endif
-
-	/* Do our best to finish without phase 2. */
-	if (work == 0)
-		return ret;  /* seccomp and/or nohz only (ret == 0 here) */
-
-#ifdef CONFIG_AUDITSYSCALL
-	if (work == _TIF_SYSCALL_AUDIT) {
-		/*
-		 * If there is no more work to be done except auditing,
-		 * then audit in phase 1.  Phase 2 always audits, so, if
-		 * we audit here, then we can't go on to phase 2.
-		 */
-		do_audit_syscall_entry(regs, arch);
-		return 0;
-	}
-#endif
-
-	return 1;  /* Something is enabled that we can't handle in phase 1 */
-}
-
-/* Returns the syscall nr to run (which should match regs->orig_ax). */
-long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch,
-				unsigned long phase1_result)
-{
-	long ret = 0;
-	u32 work = ACCESS_ONCE(current_thread_info()->flags) &
-		_TIF_WORK_SYSCALL_ENTRY;
-
-	BUG_ON(regs != task_pt_regs(current));
-
-	/*
-	 * If we stepped into a sysenter/syscall insn, it trapped in
-	 * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
-	 * If user-mode had set TF itself, then it's still clear from
-	 * do_debug() and we need to set it again to restore the user
-	 * state.  If we entered on the slow path, TF was already set.
-	 */
-	if (work & _TIF_SINGLESTEP)
-		regs->flags |= X86_EFLAGS_TF;
-
-#ifdef CONFIG_SECCOMP
-	/*
-	 * Call seccomp_phase2 before running the other hooks so that
-	 * they can see any changes made by a seccomp tracer.
-	 */
-	if (phase1_result > 1 && seccomp_phase2(phase1_result)) {
-		/* seccomp failures shouldn't expose any additional code. */
-		return -1;
-	}
-#endif
-
-	if (unlikely(work & _TIF_SYSCALL_EMU))
-		ret = -1L;
-
-	if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
-	    tracehook_report_syscall_entry(regs))
-		ret = -1L;
-
-	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
-		trace_sys_enter(regs, regs->orig_ax);
-
-	do_audit_syscall_entry(regs, arch);
-
-	return ret ?: regs->orig_ax;
-}
-
-long syscall_trace_enter(struct pt_regs *regs)
-{
-	u32 arch = is_ia32_task() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
-	unsigned long phase1_result = syscall_trace_enter_phase1(regs, arch);
-
-	if (phase1_result == 0)
-		return regs->orig_ax;
-	else
-		return syscall_trace_enter_phase2(regs, arch, phase1_result);
-}
-
-void syscall_trace_leave(struct pt_regs *regs)
-{
-	bool step;
-
-	/*
-	 * We may come here right after calling schedule_user()
-	 * or do_notify_resume(), in which case we can be in RCU
-	 * user mode.
-	 */
-	user_exit();
-
-	audit_syscall_exit(regs);
-
-	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
-		trace_sys_exit(regs, regs->ax);
-
-	/*
-	 * If TIF_SYSCALL_EMU is set, we only get here because of
-	 * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
-	 * We already reported this syscall instruction in
-	 * syscall_trace_enter().
-	 */
-	step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
-			!test_thread_flag(TIF_SYSCALL_EMU);
-	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
-
-	user_enter();
-}