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, 28 insertions, 72 deletions

diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index c0062ad1e84..df0bf0c8cb7 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -16,10 +16,13 @@
 #include <linux/uaccess.h>
 
 #include <asm/cacheflush.h>
+#include <asm/opcodes.h>
 #include <asm/ftrace.h>
 
+#include "insn.h"
+
 #ifdef CONFIG_THUMB2_KERNEL
-#define	NOP		0xeb04f85d	/* pop.w {lr} */
+#define	NOP		0xf85deb04	/* pop.w {lr} */
 #else
 #define	NOP		0xe8bd4000	/* pop {lr} */
 #endif
@@ -60,76 +63,31 @@ static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr)
 }
 #endif
 
-#ifdef CONFIG_THUMB2_KERNEL
-static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
-				       bool link)
-{
-	unsigned long s, j1, j2, i1, i2, imm10, imm11;
-	unsigned long first, second;
-	long offset;
-
-	offset = (long)addr - (long)(pc + 4);
-	if (offset < -16777216 || offset > 16777214) {
-		WARN_ON_ONCE(1);
-		return 0;
-	}
-
-	s	= (offset >> 24) & 0x1;
-	i1	= (offset >> 23) & 0x1;
-	i2	= (offset >> 22) & 0x1;
-	imm10	= (offset >> 12) & 0x3ff;
-	imm11	= (offset >>  1) & 0x7ff;
-
-	j1 = (!i1) ^ s;
-	j2 = (!i2) ^ s;
-
-	first = 0xf000 | (s << 10) | imm10;
-	second = 0x9000 | (j1 << 13) | (j2 << 11) | imm11;
-	if (link)
-		second |= 1 << 14;
-
-	return (second << 16) | first;
-}
-#else
-static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
-				       bool link)
-{
-	unsigned long opcode = 0xea000000;
-	long offset;
-
-	if (link)
-		opcode |= 1 << 24;
-
-	offset = (long)addr - (long)(pc + 8);
-	if (unlikely(offset < -33554432 || offset > 33554428)) {
-		/* Can't generate branches that far (from ARM ARM). Ftrace
-		 * doesn't generate branches outside of kernel text.
-		 */
-		WARN_ON_ONCE(1);
-		return 0;
-	}
-
-	offset = (offset >> 2) & 0x00ffffff;
-
-	return opcode | offset;
-}
-#endif
-
 static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
 {
-	return ftrace_gen_branch(pc, addr, true);
+	return arm_gen_branch_link(pc, addr);
 }
 
 static int ftrace_modify_code(unsigned long pc, unsigned long old,
-			      unsigned long new)
+			      unsigned long new, bool validate)
 {
 	unsigned long replaced;
 
-	if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE))
-		return -EFAULT;
+	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
+		old = __opcode_to_mem_thumb32(old);
+		new = __opcode_to_mem_thumb32(new);
+	} else {
+		old = __opcode_to_mem_arm(old);
+		new = __opcode_to_mem_arm(new);
+	}
 
-	if (replaced != old)
-		return -EINVAL;
+	if (validate) {
+		if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE))
+			return -EFAULT;
+
+		if (replaced != old)
+			return -EINVAL;
+	}
 
 	if (probe_kernel_write((void *)pc, &new, MCOUNT_INSN_SIZE))
 		return -EPERM;
@@ -141,23 +99,21 @@ static int ftrace_modify_code(unsigned long pc, unsigned long old,
 
 int ftrace_update_ftrace_func(ftrace_func_t func)
 {
-	unsigned long pc, old;
+	unsigned long pc;
 	unsigned long new;
 	int ret;
 
 	pc = (unsigned long)&ftrace_call;
-	memcpy(&old, &ftrace_call, MCOUNT_INSN_SIZE);
 	new = ftrace_call_replace(pc, (unsigned long)func);
 
-	ret = ftrace_modify_code(pc, old, new);
+	ret = ftrace_modify_code(pc, 0, new, false);
 
 #ifdef CONFIG_OLD_MCOUNT
 	if (!ret) {
 		pc = (unsigned long)&ftrace_call_old;
-		memcpy(&old, &ftrace_call_old, MCOUNT_INSN_SIZE);
 		new = ftrace_call_replace(pc, (unsigned long)func);
 
-		ret = ftrace_modify_code(pc, old, new);
+		ret = ftrace_modify_code(pc, 0, new, false);
 	}
 #endif
 
@@ -172,7 +128,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	old = ftrace_nop_replace(rec);
 	new = ftrace_call_replace(ip, adjust_address(rec, addr));
 
-	return ftrace_modify_code(rec->ip, old, new);
+	return ftrace_modify_code(rec->ip, old, new, true);
 }
 
 int ftrace_make_nop(struct module *mod,
@@ -185,7 +141,7 @@ int ftrace_make_nop(struct module *mod,
 
 	old = ftrace_call_replace(ip, adjust_address(rec, addr));
 	new = ftrace_nop_replace(rec);
-	ret = ftrace_modify_code(ip, old, new);
+	ret = ftrace_modify_code(ip, old, new, true);
 
 #ifdef CONFIG_OLD_MCOUNT
 	if (ret == -EINVAL && addr == MCOUNT_ADDR) {
@@ -193,7 +149,7 @@ int ftrace_make_nop(struct module *mod,
 
 		old = ftrace_call_replace(ip, adjust_address(rec, addr));
 		new = ftrace_nop_replace(rec);
-		ret = ftrace_modify_code(ip, old, new);
+		ret = ftrace_modify_code(ip, old, new, true);
 	}
 #endif
 
@@ -249,12 +205,12 @@ static int __ftrace_modify_caller(unsigned long *callsite,
 {
 	unsigned long caller_fn = (unsigned long) func;
 	unsigned long pc = (unsigned long) callsite;
-	unsigned long branch = ftrace_gen_branch(pc, caller_fn, false);
+	unsigned long branch = arm_gen_branch(pc, caller_fn);
 	unsigned long nop = 0xe1a00000;	/* mov r0, r0 */
 	unsigned long old = enable ? nop : branch;
 	unsigned long new = enable ? branch : nop;
 
-	return ftrace_modify_code(pc, old, new);
+	return ftrace_modify_code(pc, old, new, true);
 }
 
 static int ftrace_modify_graph_caller(bool enable)