Merge remote-tracking branch 'efi/urgent' into x86/urgent

There have been reports of EFI crashes since -rc1. The following two
commits fix known issues.

 * Fix boot failure on 32-bit EFI due to the recent EFI memmap changes
   merged during the merge window - Borislav Petkov

 * Avoid a crash during efi_bgrt_init() by detecting invalid BGRT
   headers based on the 'status' field.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

34 files changed, 215 insertions, 107 deletions

diff --git a/Makefile b/Makefile
index 606ef7c4a54..933e1def6ba 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 3
 PATCHLEVEL = 14
 SUBLEVEL = 0
-EXTRAVERSION = -rc1
+EXTRAVERSION = -rc2
 NAME = Shuffling Zombie Juror
 
 # *DOCUMENTATION*
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 3b978c472d0..3d6b9f81cc6 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -132,6 +132,8 @@ extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 extern void efi_sync_low_kernel_mappings(void);
 extern void efi_setup_page_tables(void);
 extern void __init old_map_region(efi_memory_desc_t *md);
+extern void __init runtime_code_page_mkexec(void);
+extern void __init efi_runtime_mkexec(void);
 
 struct efi_setup_data {
 	u64 fw_vendor;
diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c
index 4df9591eada..f15103dff4b 100644
--- a/arch/x86/platform/efi/efi-bgrt.c
+++ b/arch/x86/platform/efi/efi-bgrt.c
@@ -42,7 +42,7 @@ void __init efi_bgrt_init(void)
 
 	if (bgrt_tab->header.length < sizeof(*bgrt_tab))
 		return;
-	if (bgrt_tab->version != 1)
+	if (bgrt_tab->version != 1 || bgrt_tab->status != 1)
 		return;
 	if (bgrt_tab->image_type != 0 || !bgrt_tab->image_address)
 		return;
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index d62ec87a2b2..1a201ac7cef 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -792,7 +792,7 @@ void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
 		set_memory_nx(addr, npages);
 }
 
-static void __init runtime_code_page_mkexec(void)
+void __init runtime_code_page_mkexec(void)
 {
 	efi_memory_desc_t *md;
 	void *p;
@@ -1069,8 +1069,7 @@ void __init efi_enter_virtual_mode(void)
 	efi.update_capsule = virt_efi_update_capsule;
 	efi.query_capsule_caps = virt_efi_query_capsule_caps;
 
-	if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
-		runtime_code_page_mkexec();
+	efi_runtime_mkexec();
 
 	kfree(new_memmap);
 
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 249b183cf41..0b74cdf7f81 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -77,3 +77,9 @@ void efi_call_phys_epilog(void)
 
 	local_irq_restore(efi_rt_eflags);
 }
+
+void __init efi_runtime_mkexec(void)
+{
+	if (__supported_pte_mask & _PAGE_NX)
+		runtime_code_page_mkexec();
+}
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 6284f158a47..0c2a234fef1 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -233,3 +233,12 @@ void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 {
 	efi_setup = phys_addr + sizeof(struct setup_data);
 }
+
+void __init efi_runtime_mkexec(void)
+{
+	if (!efi_enabled(EFI_OLD_MEMMAP))
+		return;
+
+	if (__supported_pte_mask & _PAGE_NX)
+		runtime_code_page_mkexec();
+}
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index feea87cc6b8..6928d094451 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -890,12 +890,10 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 	} else {
 		/* Failback to copying a page */
 		struct page *page = alloc_page(GFP_KERNEL);
-		char *src = buf->ops->map(pipe, buf, 1);
-		char *dst;
+		char *src;
 
 		if (!page)
 			return -ENOMEM;
-		dst = kmap(page);
 
 		offset = sd->pos & ~PAGE_MASK;
 
@@ -903,9 +901,8 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 		if (len + offset > PAGE_SIZE)
 			len = PAGE_SIZE - offset;
 
-		memcpy(dst + offset, src + buf->offset, len);
-
-		kunmap(page);
+		src = buf->ops->map(pipe, buf, 1);
+		memcpy(page_address(page) + offset, src + buf->offset, len);
 		buf->ops->unmap(pipe, buf, src);
 
 		sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index e2600cdb6c2..b01fb6c527e 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1010,6 +1010,8 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
 		bytes = min(bytes, working_bytes);
 		kaddr = kmap_atomic(page_out);
 		memcpy(kaddr + *pg_offset, buf + buf_offset, bytes);
+		if (*pg_index == (vcnt - 1) && *pg_offset == 0)
+			memset(kaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
 		kunmap_atomic(kaddr);
 		flush_dcache_page(page_out);
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 9c9ecc93ae2..32312e09f0f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2385,6 +2385,7 @@ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			spin_unlock(&delayed_refs->lock);
 			locked_ref = NULL;
 			cond_resched();
+			count++;
 			continue;
 		}
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b0134892dc7..383ab455bfa 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4525,7 +4525,7 @@ static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
 	spin_lock(&root->fs_info->super_lock);
 	strcpy(super_block->label, label);
 	spin_unlock(&root->fs_info->super_lock);
-	ret = btrfs_end_transaction(trans, root);
+	ret = btrfs_commit_transaction(trans, root);
 
 out_unlock:
 	mnt_drop_write_file(file);
@@ -4668,7 +4668,7 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
 	if (ret)
 		return ret;
 
-	trans = btrfs_start_transaction(root, 1);
+	trans = btrfs_start_transaction(root, 0);
 	if (IS_ERR(trans))
 		return PTR_ERR(trans);
 
@@ -4689,7 +4689,7 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
 	btrfs_set_super_incompat_flags(super_block, newflags);
 	spin_unlock(&root->fs_info->super_lock);
 
-	return btrfs_end_transaction(trans, root);
+	return btrfs_commit_transaction(trans, root);
 }
 
 long btrfs_ioctl(struct file *file, unsigned int
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index cf9107a6420..9c8d1a3fdc3 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -2774,8 +2774,6 @@ static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino)
 	return 0;
 }
 
-#ifdef CONFIG_BTRFS_ASSERT
-
 static int del_waiting_dir_move(struct send_ctx *sctx, u64 ino)
 {
 	struct rb_node *n = sctx->waiting_dir_moves.rb_node;
@@ -2796,8 +2794,6 @@ static int del_waiting_dir_move(struct send_ctx *sctx, u64 ino)
 	return -ENOENT;
 }
 
-#endif
-
 static int add_pending_dir_move(struct send_ctx *sctx, u64 parent_ino)
 {
 	struct rb_node **p = &sctx->pending_dir_moves.rb_node;
@@ -2902,7 +2898,9 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
 	}
 
 	sctx->send_progress = sctx->cur_ino + 1;
-	ASSERT(del_waiting_dir_move(sctx, pm->ino) == 0);
+	ret = del_waiting_dir_move(sctx, pm->ino);
+	ASSERT(ret == 0);
+
 	ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
 	if (ret < 0)
 		goto out;
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 853d6d1cc82..a7eda8ebfac 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2559,8 +2559,8 @@ cifs_writev(struct kiocb *iocb, const struct iovec *iov,
 	if (rc > 0) {
 		ssize_t err;
 
-		err = generic_write_sync(file, pos, rc);
-		if (err < 0 && rc > 0)
+		err = generic_write_sync(file, iocb->ki_pos - rc, rc);
+		if (err < 0)
 			rc = err;
 	}
 
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 43e64f6022e..1a5073959f3 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -152,7 +152,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 	if (ret > 0) {
 		ssize_t err;
 
-		err = generic_write_sync(file, pos, ret);
+		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
 		if (err < 0 && ret > 0)
 			ret = err;
 	}
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index ea4ba9daeb4..db9bd8a3172 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -2134,7 +2134,7 @@ static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	ret = ntfs_file_aio_write_nolock(iocb, iov, nr_segs, &iocb->ki_pos);
 	mutex_unlock(&inode->i_mutex);
 	if (ret > 0) {
-		int err = generic_write_sync(file, pos, ret);
+		int err = generic_write_sync(file, iocb->ki_pos - ret, ret);
 		if (err < 0)
 			ret = err;
 	}
diff --git a/fs/sync.c b/fs/sync.c
index f1553745223..e8ba024a055 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -222,23 +222,6 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
 	return do_fsync(fd, 1);
 }
 
-/**
- * generic_write_sync - perform syncing after a write if file / inode is sync
- * @file:	file to which the write happened
- * @pos:	offset where the write started
- * @count:	length of the write
- *
- * This is just a simple wrapper about our general syncing function.
- */
-int generic_write_sync(struct file *file, loff_t pos, loff_t count)
-{
-	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
-		return 0;
-	return vfs_fsync_range(file, pos, pos + count - 1,
-			       (file->f_flags & __O_SYNC) ? 0 : 1);
-}
-EXPORT_SYMBOL(generic_write_sync);
-
 /*
  * sys_sync_file_range() permits finely controlled syncing over a segment of
  * a file in the range offset .. (offset+nbytes-1) inclusive.  If nbytes is
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 2e7989e3a2d..64b48eade91 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -799,7 +799,7 @@ xfs_file_aio_write(
 		XFS_STATS_ADD(xs_write_bytes, ret);
 
 		/* Handle various SYNC-type writes */
-		err = generic_write_sync(file, pos, ret);
+		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
 		if (err < 0)
 			ret = err;
 	}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d79678c188a..60829565e55 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2274,7 +2274,13 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
 			   int datasync);
 extern int vfs_fsync(struct file *file, int datasync);
-extern int generic_write_sync(struct file *file, loff_t pos, loff_t count);
+static inline int generic_write_sync(struct file *file, loff_t pos, loff_t count)
+{
+	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
+		return 0;
+	return vfs_fsync_range(file, pos, pos + count - 1,
+			       (file->f_flags & __O_SYNC) ? 0 : 1);
+}
 extern void emergency_sync(void);
 extern void emergency_remount(void);
 #ifdef CONFIG_BLOCK
diff --git a/mm/filemap.c b/mm/filemap.c
index d56d3c145b9..7a13f6ac542 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2553,8 +2553,8 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	if (ret > 0) {
 		ssize_t err;
 
-		err = generic_write_sync(file, pos, ret);
-		if (err < 0 && ret > 0)
+		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+		if (err < 0)
 			ret = err;
 	}
 	return ret;
diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
index 332ac8a80cf..2df7b900e25 100644
--- a/security/selinux/nlmsgtab.c
+++ b/security/selinux/nlmsgtab.c
@@ -17,6 +17,7 @@
 #include <linux/inet_diag.h>
 #include <linux/xfrm.h>
 #include <linux/audit.h>
+#include <linux/sock_diag.h>
 
 #include "flask.h"
 #include "av_permissions.h"
@@ -78,6 +79,7 @@ static struct nlmsg_perm nlmsg_tcpdiag_perms[] =
 {
 	{ TCPDIAG_GETSOCK,	NETLINK_TCPDIAG_SOCKET__NLMSG_READ },
 	{ DCCPDIAG_GETSOCK,	NETLINK_TCPDIAG_SOCKET__NLMSG_READ },
+	{ SOCK_DIAG_BY_FAMILY,	NETLINK_TCPDIAG_SOCKET__NLMSG_READ },
 };
 
 static struct nlmsg_perm nlmsg_xfrm_perms[] =
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index c93c21127f0..5d0144ee8ed 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1232,6 +1232,10 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
 	struct context context;
 	int rc = 0;
 
+	/* An empty security context is never valid. */
+	if (!scontext_len)
+		return -EINVAL;
+
 	if (!ss_initialized) {
 		int i;
 
diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index cfede86161d..b22dbb16f87 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -63,11 +63,35 @@ static int build_id_cache__kcore_dir(char *dir, size_t sz)
 	return 0;
 }
 
+static bool same_kallsyms_reloc(const char *from_dir, char *to_dir)
+{
+	char from[PATH_MAX];
+	char to[PATH_MAX];
+	const char *name;
+	u64 addr1 = 0, addr2 = 0;
+	int i;
+
+	scnprintf(from, sizeof(from), "%s/kallsyms", from_dir);
+	scnprintf(to, sizeof(to), "%s/kallsyms", to_dir);
+
+	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
+		addr1 = kallsyms__get_function_start(from, name);
+		if (addr1)
+			break;
+	}
+
+	if (name)
+		addr2 = kallsyms__get_function_start(to, name);
+
+	return addr1 == addr2;
+}
+
 static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
 					  size_t to_dir_sz)
 {
 	char from[PATH_MAX];
 	char to[PATH_MAX];
+	char to_subdir[PATH_MAX];
 	struct dirent *dent;
 	int ret = -1;
 	DIR *d;
@@ -86,10 +110,11 @@ static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
 			continue;
 		scnprintf(to, sizeof(to), "%s/%s/modules", to_dir,
 			  dent->d_name);
-		if (!compare_proc_modules(from, to)) {
-			scnprintf(to, sizeof(to), "%s/%s", to_dir,
-				  dent->d_name);
-			strlcpy(to_dir, to, to_dir_sz);
+		scnprintf(to_subdir, sizeof(to_subdir), "%s/%s",
+			  to_dir, dent->d_name);
+		if (!compare_proc_modules(from, to) &&
+		    same_kallsyms_reloc(from_dir, to_subdir)) {
+			strlcpy(to_dir, to_subdir, to_dir_sz);
 			ret = 0;
 			break;
 		}
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3c394bf16fa..af47531b82e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -287,10 +287,7 @@ static void perf_event__synthesize_guest_os(struct machine *machine, void *data)
 	 * have no _text sometimes.
 	 */
 	err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
-						 machine, "_text");
-	if (err < 0)
-		err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
-							 machine, "_stext");
+						 machine);
 	if (err < 0)
 		pr_err("Couldn't record guest kernel [%d]'s reference"
 		       " relocation symbol.\n", machine->pid);
@@ -457,10 +454,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	}
 
 	err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
-						 machine, "_text");
-	if (err < 0)
-		err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
-							 machine, "_stext");
+						 machine);
 	if (err < 0)
 		pr_err("Couldn't record kernel reference relocation symbol\n"
 		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
diff --git a/tools/perf/design.txt b/tools/perf/design.txt
index 67e5d0cace8..63a0e6f04a0 100644
--- a/tools/perf/design.txt
+++ b/tools/perf/design.txt
@@ -454,7 +454,6 @@ So to start with, in order to add HAVE_PERF_EVENTS to your Kconfig, you
 will need at least this:
 	- asm/perf_event.h - a basic stub will suffice at first
 	- support for atomic64 types (and associated helper functions)
-	- set_perf_event_pending() implemented
 
 If your architecture does have hardware capabilities, you can override the
 weak stub hw_perf_event_init() to register hardware counters.
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 7daa806d905..e84fa26bc1b 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -100,8 +100,8 @@
 
 #ifdef __aarch64__
 #define mb()		asm volatile("dmb ish" ::: "memory")
-#define wmb()		asm volatile("dmb ishld" ::: "memory")
-#define rmb()		asm volatile("dmb ishst" ::: "memory")
+#define wmb()		asm volatile("dmb ishst" ::: "memory")
+#define rmb()		asm volatile("dmb ishld" ::: "memory")
 #define cpu_relax()	asm volatile("yield" ::: "memory")
 #endif
 
diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c
index 2bd13edcbc1..3d9088003a5 100644
--- a/tools/perf/tests/vmlinux-kallsyms.c
+++ b/tools/perf/tests/vmlinux-kallsyms.c
@@ -26,7 +26,6 @@ int test__vmlinux_matches_kallsyms(void)
 	struct map *kallsyms_map, *vmlinux_map;
 	struct machine kallsyms, vmlinux;
 	enum map_type type = MAP__FUNCTION;
-	struct ref_reloc_sym ref_reloc_sym = { .name = "_stext", };
 	u64 mem_start, mem_end;
 
 	/*
@@ -70,14 +69,6 @@ int test__vmlinux_matches_kallsyms(void)
 	 */
 	kallsyms_map = machine__kernel_map(&kallsyms, type);
 
-	sym = map__find_symbol_by_name(kallsyms_map, ref_reloc_sym.name, NULL);
-	if (sym == NULL) {
-		pr_debug("dso__find_symbol_by_name ");
-		goto out;
-	}
-
-	ref_reloc_sym.addr = UM(sym->start);
-
 	/*
 	 * Step 5:
 	 *
@@ -89,7 +80,6 @@ int test__vmlinux_matches_kallsyms(void)
 	}
 
 	vmlinux_map = machine__kernel_map(&vmlinux, type);
-	map__kmap(vmlinux_map)->ref_reloc_sym = &ref_reloc_sym;
 
 	/*
 	 * Step 6:
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 1fc1c2f0477..b0f3ca850e9 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -470,23 +470,32 @@ static int find_symbol_cb(void *arg, const char *name, char type,
 	return 1;
 }
 
+u64 kallsyms__get_function_start(const char *kallsyms_filename,
+				 const char *symbol_name)
+{
+	struct process_symbol_args args = { .name = symbol_name, };
+
+	if (kallsyms__parse(kallsyms_filename, &args, find_symbol_cb) <= 0)
+		return 0;
+
+	return args.start;
+}
+
 int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
 				       perf_event__handler_t process,
-				       struct machine *machine,
-				       const char *symbol_name)
+				       struct machine *machine)
 {
 	size_t size;
-	const char *filename, *mmap_name;
-	char path[PATH_MAX];
+	const char *mmap_name;
 	char name_buff[PATH_MAX];
 	struct map *map;
+	struct kmap *kmap;
 	int err;
 	/*
 	 * We should get this from /sys/kernel/sections/.text, but till that is
 	 * available use this, and after it is use this as a fallback for older
 	 * kernels.
 	 */
-	struct process_symbol_args args = { .name = symbol_name, };
 	union perf_event *event = zalloc((sizeof(event->mmap) +
 					  machine->id_hdr_size));
 	if (event == NULL) {
@@ -502,30 +511,19 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
 		 * see kernel/perf_event.c __perf_event_mmap
 		 */
 		event->header.misc = PERF_RECORD_MISC_KERNEL;
-		filename = "/proc/kallsyms";
 	} else {
 		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
-		if (machine__is_default_guest(machine))
-			filename = (char *) symbol_conf.default_guest_kallsyms;
-		else {
-			sprintf(path, "%s/proc/kallsyms", machine->root_dir);
-			filename = path;
-		}
-	}
-
-	if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0) {
-		free(event);
-		return -ENOENT;
 	}
 
 	map = machine->vmlinux_maps[MAP__FUNCTION];
+	kmap = map__kmap(map);
 	size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
-			"%s%s", mmap_name, symbol_name) + 1;
+			"%s%s", mmap_name, kmap->ref_reloc_sym->name) + 1;
 	size = PERF_ALIGN(size, sizeof(u64));
 	event->mmap.header.type = PERF_RECORD_MMAP;
 	event->mmap.header.size = (sizeof(event->mmap) -
 			(sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
-	event->mmap.pgoff = args.start;
+	event->mmap.pgoff = kmap->ref_reloc_sym->addr;
 	event->mmap.start = map->start;
 	event->mmap.len   = map->end - event->mmap.start;
 	event->mmap.pid   = machine->pid;
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index faf6e219be2..851fa06f4a4 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -214,8 +214,7 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
 				   struct machine *machine, bool mmap_data);
 int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
 				       perf_event__handler_t process,
-				       struct machine *machine,
-				       const char *symbol_name);
+				       struct machine *machine);
 
 int perf_event__synthesize_modules(struct perf_tool *tool,
 				   perf_event__handler_t process,
@@ -279,4 +278,7 @@ size_t perf_event__fprintf_mmap2(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_task(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf(union perf_event *event, FILE *fp);
 
+u64 kallsyms__get_function_start(const char *kallsyms_filename,
+				 const char *symbol_name);
+
 #endif /* __PERF_RECORD_H */
diff --git a/tools/perf/util/include/asm/hash.h b/tools/perf/util/include/asm/hash.h
new file mode 100644
index 00000000000..d82b170bb21
--- /dev/null
+++ b/tools/perf/util/include/asm/hash.h
@@ -0,0 +1,6 @@
+#ifndef __ASM_GENERIC_HASH_H
+#define __ASM_GENERIC_HASH_H
+
+/* Stub */
+
+#endif /* __ASM_GENERIC_HASH_H */
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index ded74590b92..c872991e0f6 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -496,19 +496,22 @@ static int symbol__in_kernel(void *arg, const char *name,
 	return 1;
 }
 
+static void machine__get_kallsyms_filename(struct machine *machine, char *buf,
+					   size_t bufsz)
+{
+	if (machine__is_default_guest(machine))
+		scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
+	else
+		scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
+}
+
 /* Figure out the start address of kernel map from /proc/kallsyms */
 static u64 machine__get_kernel_start_addr(struct machine *machine)
 {
-	const char *filename;
-	char path[PATH_MAX];
+	char filename[PATH_MAX];
 	struct process_args args;
 
-	if (machine__is_default_guest(machine))
-		filename = (char *)symbol_conf.default_guest_kallsyms;
-	else {
-		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
-		filename = path;
-	}
+	machine__get_kallsyms_filename(machine, filename, PATH_MAX);
 
 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
 		return 0;
@@ -829,9 +832,25 @@ static int machine__create_modules(struct machine *machine)
 	return 0;
 }
 
+const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
+
 int machine__create_kernel_maps(struct machine *machine)
 {
 	struct dso *kernel = machine__get_kernel(machine);
+	char filename[PATH_MAX];
+	const char *name;
+	u64 addr = 0;
+	int i;
+
+	machine__get_kallsyms_filename(machine, filename, PATH_MAX);
+
+	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
+		addr = kallsyms__get_function_start(filename, name);
+		if (addr)
+			break;
+	}
+	if (!addr)
+		return -1;
 
 	if (kernel == NULL ||
 	    __machine__create_kernel_maps(machine, kernel) < 0)
@@ -850,6 +869,13 @@ int machine__create_kernel_maps(struct machine *machine)
 	 * Now that we have all the maps created, just set the ->end of them:
 	 */
 	map_groups__fixup_end(&machine->kmaps);
+
+	if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name,
+					     addr)) {
+		machine__destroy_kernel_maps(machine);
+		return -1;
+	}
+
 	return 0;
 }
 
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 47713301544..f77e91e483d 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -18,6 +18,8 @@ union perf_event;
 #define	HOST_KERNEL_ID			(-1)
 #define	DEFAULT_GUEST_KERNEL_ID		(0)
 
+extern const char *ref_reloc_sym_names[];
+
 struct machine {
 	struct rb_node	  rb_node;
 	pid_t		  pid;
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 3b97513f0e7..39cd2d0faff 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -39,6 +39,7 @@ void map__init(struct map *map, enum map_type type,
 	map->start    = start;
 	map->end      = end;
 	map->pgoff    = pgoff;
+	map->reloc    = 0;
 	map->dso      = dso;
 	map->map_ip   = map__map_ip;
 	map->unmap_ip = map__unmap_ip;
@@ -288,7 +289,7 @@ u64 map__rip_2objdump(struct map *map, u64 rip)
 	if (map->dso->rel)
 		return rip - map->pgoff;
 
-	return map->unmap_ip(map, rip);
+	return map->unmap_ip(map, rip) - map->reloc;
 }
 
 /**
@@ -31