Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 115 insertions, 45 deletions

diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
index 3f7ad83ed74..3aa9a969b37 100644
--- a/drivers/misc/kgdbts.c
+++ b/drivers/misc/kgdbts.c
@@ -134,12 +134,17 @@ static int force_hwbrks;
 static int hwbreaks_ok;
 static int hw_break_val;
 static int hw_break_val2;
+static int cont_instead_of_sstep;
+static unsigned long cont_thread_id;
+static unsigned long sstep_thread_id;
 #if defined(CONFIG_ARM) || defined(CONFIG_MIPS) || defined(CONFIG_SPARC)
 static int arch_needs_sstep_emulation = 1;
 #else
 static int arch_needs_sstep_emulation;
 #endif
+static unsigned long cont_addr;
 static unsigned long sstep_addr;
+static int restart_from_top_after_write;
 static int sstep_state;
 
 /* Storage for the registers, in GDB format. */
@@ -187,7 +192,8 @@ static int kgdbts_unreg_thread(void *ptr)
 	 */
 	while (!final_ack)
 		msleep_interruptible(1500);
-
+	/* Pause for any other threads to exit after final ack. */
+	msleep_interruptible(1000);
 	if (configured)
 		kgdb_unregister_io_module(&kgdbts_io_ops);
 	configured = 0;
@@ -211,7 +217,7 @@ static unsigned long lookup_addr(char *arg)
 	if (!strcmp(arg, "kgdbts_break_test"))
 		addr = (unsigned long)kgdbts_break_test;
 	else if (!strcmp(arg, "sys_open"))
-		addr = (unsigned long)sys_open;
+		addr = (unsigned long)do_sys_open;
 	else if (!strcmp(arg, "do_fork"))
 		addr = (unsigned long)do_fork;
 	else if (!strcmp(arg, "hw_break_val"))
@@ -283,6 +289,16 @@ static void hw_break_val_write(void)
 	hw_break_val++;
 }
 
+static int get_thread_id_continue(char *put_str, char *arg)
+{
+	char *ptr = &put_str[11];
+
+	if (put_str[1] != 'T' || put_str[2] != '0')
+		return 1;
+	kgdb_hex2long(&ptr, &cont_thread_id);
+	return 0;
+}
+
 static int check_and_rewind_pc(char *put_str, char *arg)
 {
 	unsigned long addr = lookup_addr(arg);
@@ -299,13 +315,21 @@ static int check_and_rewind_pc(char *put_str, char *arg)
 	if (addr + BREAK_INSTR_SIZE == ip)
 		offset = -BREAK_INSTR_SIZE;
 #endif
-	if (strcmp(arg, "silent") && ip + offset != addr) {
+
+	if (arch_needs_sstep_emulation && sstep_addr &&
+	    ip + offset == sstep_addr &&
+	    ((!strcmp(arg, "sys_open") || !strcmp(arg, "do_fork")))) {
+		/* This is special case for emulated single step */
+		v2printk("Emul: rewind hit single step bp\n");
+		restart_from_top_after_write = 1;
+	} else if (strcmp(arg, "silent") && ip + offset != addr) {
 		eprintk("kgdbts: BP mismatch %lx expected %lx\n",
 			   ip + offset, addr);
 		return 1;
 	}
 	/* Readjust the instruction pointer if needed */
 	ip += offset;
+	cont_addr = ip;
 #ifdef GDB_ADJUSTS_BREAK_OFFSET
 	instruction_pointer_set(&kgdbts_regs, ip);
 #endif
@@ -315,6 +339,8 @@ static int check_and_rewind_pc(char *put_str, char *arg)
 static int check_single_step(char *put_str, char *arg)
 {
 	unsigned long addr = lookup_addr(arg);
+	static int matched_id;
+
 	/*
 	 * From an arch indepent point of view the instruction pointer
 	 * should be on a different instruction
@@ -324,6 +350,29 @@ static int check_single_step(char *put_str, char *arg)
 	gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
 	v2printk("Singlestep stopped at IP: %lx\n",
 		   instruction_pointer(&kgdbts_regs));
+
+	if (sstep_thread_id != cont_thread_id) {
+		/*
+		 * Ensure we stopped in the same thread id as before, else the
+		 * debugger should continue until the original thread that was
+		 * single stepped is scheduled again, emulating gdb's behavior.
+		 */
+		v2printk("ThrID does not match: %lx\n", cont_thread_id);
+		if (arch_needs_sstep_emulation) {
+			if (matched_id &&
+			    instruction_pointer(&kgdbts_regs) != addr)
+				goto continue_test;
+			matched_id++;
+			ts.idx -= 2;
+			sstep_state = 0;
+			return 0;
+		}
+		cont_instead_of_sstep = 1;
+		ts.idx -= 4;
+		return 0;
+	}
+continue_test:
+	matched_id = 0;
 	if (instruction_pointer(&kgdbts_regs) == addr) {
 		eprintk("kgdbts: SingleStep failed at %lx\n",
 			   instruction_pointer(&kgdbts_regs));
@@ -365,10 +414,40 @@ static int got_break(char *put_str, char *arg)
 	return 1;
 }
 
+static void get_cont_catch(char *arg)
+{
+	/* Always send detach because the test is completed at this point */
+	fill_get_buf("D");
+}
+
+static int put_cont_catch(char *put_str, char *arg)
+{
+	/* This is at the end of the test and we catch any and all input */
+	v2printk("kgdbts: cleanup task: %lx\n", sstep_thread_id);
+	ts.idx--;
+	return 0;
+}
+
+static int emul_reset(char *put_str, char *arg)
+{
+	if (strncmp(put_str, "$OK", 3))
+		return 1;
+	if (restart_from_top_after_write) {
+		restart_from_top_after_write = 0;
+		ts.idx = -1;
+	}
+	return 0;
+}
+
 static void emul_sstep_get(char *arg)
 {
 	if (!arch_needs_sstep_emulation) {
-		fill_get_buf(arg);
+		if (cont_instead_of_sstep) {
+			cont_instead_of_sstep = 0;
+			fill_get_buf("c");
+		} else {
+			fill_get_buf(arg);
+		}
 		return;
 	}
 	switch (sstep_state) {
@@ -398,9 +477,11 @@ static void emul_sstep_get(char *arg)
 static int emul_sstep_put(char *put_str, char *arg)
 {
 	if (!arch_needs_sstep_emulation) {
-		if (!strncmp(put_str+1, arg, 2))
-			return 0;
-		return 1;
+		char *ptr = &put_str[11];
+		if (put_str[1] != 'T' || put_str[2] != '0')
+			return 1;
+		kgdb_hex2long(&ptr, &sstep_thread_id);
+		return 0;
 	}
 	switch (sstep_state) {
 	case 1:
@@ -411,8 +492,7 @@ static int emul_sstep_put(char *put_str, char *arg)
 		v2printk("Stopped at IP: %lx\n",
 			 instruction_pointer(&kgdbts_regs));
 		/* Want to stop at IP + break instruction size by default */
-		sstep_addr = instruction_pointer(&kgdbts_regs) +
-			BREAK_INSTR_SIZE;
+		sstep_addr = cont_addr + BREAK_INSTR_SIZE;
 		break;
 	case 2:
 		if (strncmp(put_str, "$OK", 3)) {
@@ -424,6 +504,9 @@ static int emul_sstep_put(char *put_str, char *arg)
 		if (strncmp(put_str, "$T0", 3)) {
 			eprintk("kgdbts: failed continue sstep\n");
 			return 1;
+		} else {
+			char *ptr = &put_str[11];
+			kgdb_hex2long(&ptr, &sstep_thread_id);
 		}
 		break;
 	case 4:
@@ -502,10 +585,10 @@ static struct test_struct bad_read_test[] = {
 static struct test_struct singlestep_break_test[] = {
 	{ "?", "S0*" }, /* Clear break points */
 	{ "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
-	{ "c", "T0*", }, /* Continue */
+	{ "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
+	{ "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
 	{ "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
 	{ "write", "OK", write_regs }, /* Write registers */
-	{ "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
 	{ "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
 	{ "g", "kgdbts_break_test", NULL, check_single_step },
 	{ "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
@@ -523,16 +606,16 @@ static struct test_struct singlestep_break_test[] = {
 static struct test_struct do_fork_test[] = {
 	{ "?", "S0*" }, /* Clear break points */
 	{ "do_fork", "OK", sw_break, }, /* set sw breakpoint */
-	{ "c", "T0*", }, /* Continue */
-	{ "g", "do_fork", NULL, check_and_rewind_pc }, /* check location */
-	{ "write", "OK", write_regs }, /* Write registers */
+	{ "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
 	{ "do_fork", "OK", sw_rem_break }, /*remove breakpoint */
+	{ "g", "do_fork", NULL, check_and_rewind_pc }, /* check location */
+	{ "write", "OK", write_regs, emul_reset }, /* Write registers */
 	{ "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
 	{ "g", "do_fork", NULL, check_single_step },
 	{ "do_fork", "OK", sw_break, }, /* set sw breakpoint */
 	{ "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
 	{ "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
-	{ "", "" },
+	{ "", "", get_cont_catch, put_cont_catch },
 };
 
 /* Test for hitting a breakpoint at sys_open for what ever the number
@@ -541,16 +624,16 @@ static struct test_struct do_fork_test[] = {
 static struct test_struct sys_open_test[] = {
 	{ "?", "S0*" }, /* Clear break points */
 	{ "sys_open", "OK", sw_break, }, /* set sw breakpoint */
-	{ "c", "T0*", }, /* Continue */
-	{ "g", "sys_open", NULL, check_and_rewind_pc }, /* check location */
-	{ "write", "OK", write_regs }, /* Write registers */
+	{ "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
 	{ "sys_open", "OK", sw_rem_break }, /*remove breakpoint */
+	{ "g", "sys_open", NULL, check_and_rewind_pc }, /* check location */
+	{ "write", "OK", write_regs, emul_reset }, /* Write registers */
 	{ "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
 	{ "g", "sys_open", NULL, check_single_step },
 	{ "sys_open", "OK", sw_break, }, /* set sw breakpoint */
 	{ "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
 	{ "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
-	{ "", "" },
+	{ "", "", get_cont_catch, put_cont_catch },
 };
 
 /*
@@ -693,8 +776,8 @@ static int run_simple_test(int is_get_char, int chr)
 	/* This callback is a put char which is when kgdb sends data to
 	 * this I/O module.
 	 */
-	if (ts.tst[ts.idx].get[0] == '\0' &&
-		ts.tst[ts.idx].put[0] == '\0') {
+	if (ts.tst[ts.idx].get[0] == '\0' && ts.tst[ts.idx].put[0] == '\0' &&
+	    !ts.tst[ts.idx].get_handler) {
 		eprintk("kgdbts: ERROR: beyond end of test on"
 			   " '%s' line %i\n", ts.name, ts.idx);
 		return 0;
@@ -907,6 +990,17 @@ static void kgdbts_run_tests(void)
 	if (ptr)
 		sstep_test = simple_strtol(ptr+1, NULL, 10);
 
+	/* All HW break point tests */
+	if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) {
+		hwbreaks_ok = 1;
+		v1printk("kgdbts:RUN hw breakpoint test\n");
+		run_breakpoint_test(1);
+		v1printk("kgdbts:RUN hw write breakpoint test\n");
+		run_hw_break_test(1);
+		v1printk("kgdbts:RUN access write breakpoint test\n");
+		run_hw_break_test(0);
+	}
+
 	/* required internal KGDB tests */
 	v1printk("kgdbts:RUN plant and detach test\n");
 	run_plant_and_detach_test(0);
@@ -924,35 +1018,11 @@ static void kgdbts_run_tests(void)
 
 	/* ===Optional tests=== */
 
-	/* All HW break point tests */
-	if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) {
-		hwbreaks_ok = 1;
-		v1printk("kgdbts:RUN hw breakpoint test\n");
-		run_breakpoint_test(1);
-		v1printk("kgdbts:RUN hw write breakpoint test\n");
-		run_hw_break_test(1);
-		v1printk("kgdbts:RUN access write breakpoint test\n");
-		run_hw_break_test(0);
-	}
-
 	if (nmi_sleep) {
 		v1printk("kgdbts:RUN NMI sleep %i seconds test\n", nmi_sleep);
 		run_nmi_sleep_test(nmi_sleep);
 	}
 
-#ifdef CONFIG_DEBUG_RODATA
-	/* Until there is an api to write to read-only text segments, use
-	 * HW breakpoints for the remainder of any tests, else print a
-	 * failure message if hw breakpoints do not work.
-	 */
-	if (!(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT && hwbreaks_ok)) {
-		eprintk("kgdbts: HW breakpoints do not work,"
-			"skipping remaining tests\n");
-		return;
-	}
-	force_hwbrks = 1;
-#endif /* CONFIG_DEBUG_RODATA */
-
 	/* If the do_fork test is run it will be the last test that is
 	 * executed because a kernel thread will be spawned at the very
 	 * end to unregister the debug hooks.