Merge "Merge android-4.4.110 (5cc8c2e) into msm-4.4"

3 files changed, 125 insertions, 3 deletions

diff --git a/Documentation/kasan.txt b/Documentation/kasan.txt
index aa1e0c91e368..7dd95b35cd7c 100644
--- a/Documentation/kasan.txt
+++ b/Documentation/kasan.txt
@@ -12,8 +12,7 @@ KASAN uses compile-time instrumentation for checking every memory access,
 therefore you will need a GCC version 4.9.2 or later. GCC 5.0 or later is
 required for detection of out-of-bounds accesses to stack or global variables.
 
-Currently KASAN is supported only for x86_64 architecture and requires the
-kernel to be built with the SLUB allocator.
+Currently KASAN is supported only for x86_64 architecture.
 
 1. Usage
 ========
@@ -27,7 +26,7 @@ inline are compiler instrumentation types. The former produces smaller binary
 the latter is 1.1 - 2 times faster. Inline instrumentation requires a GCC
 version 5.0 or later.
 
-Currently KASAN works only with the SLUB memory allocator.
+KASAN works with both SLUB and SLAB memory allocators.
 For better bug detection and nicer reporting, enable CONFIG_STACKTRACE.
 
 To disable instrumentation for specific files or directories, add a line
diff --git a/Documentation/kcov.txt b/Documentation/kcov.txt
new file mode 100644
index 000000000000..779ff4ab1c1d
--- /dev/null
+++ b/Documentation/kcov.txt
@@ -0,0 +1,111 @@
+kcov: code coverage for fuzzing
+===============================
+
+kcov exposes kernel code coverage information in a form suitable for coverage-
+guided fuzzing (randomized testing). Coverage data of a running kernel is
+exported via the "kcov" debugfs file. Coverage collection is enabled on a task
+basis, and thus it can capture precise coverage of a single system call.
+
+Note that kcov does not aim to collect as much coverage as possible. It aims
+to collect more or less stable coverage that is function of syscall inputs.
+To achieve this goal it does not collect coverage in soft/hard interrupts
+and instrumentation of some inherently non-deterministic parts of kernel is
+disbled (e.g. scheduler, locking).
+
+Usage:
+======
+
+Configure kernel with:
+
+        CONFIG_KCOV=y
+
+CONFIG_KCOV requires gcc built on revision 231296 or later.
+Profiling data will only become accessible once debugfs has been mounted:
+
+        mount -t debugfs none /sys/kernel/debug
+
+The following program demonstrates kcov usage from within a test program:
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#define KCOV_INIT_TRACE			_IOR('c', 1, unsigned long)
+#define KCOV_ENABLE			_IO('c', 100)
+#define KCOV_DISABLE			_IO('c', 101)
+#define COVER_SIZE			(64<<10)
+
+int main(int argc, char **argv)
+{
+	int fd;
+	unsigned long *cover, n, i;
+
+	/* A single fd descriptor allows coverage collection on a single
+	 * thread.
+	 */
+	fd = open("/sys/kernel/debug/kcov", O_RDWR);
+	if (fd == -1)
+		perror("open"), exit(1);
+	/* Setup trace mode and trace size. */
+	if (ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE))
+		perror("ioctl"), exit(1);
+	/* Mmap buffer shared between kernel- and user-space. */
+	cover = (unsigned long*)mmap(NULL, COVER_SIZE * sizeof(unsigned long),
+				     PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if ((void*)cover == MAP_FAILED)
+		perror("mmap"), exit(1);
+	/* Enable coverage collection on the current thread. */
+	if (ioctl(fd, KCOV_ENABLE, 0))
+		perror("ioctl"), exit(1);
+	/* Reset coverage from the tail of the ioctl() call. */
+	__atomic_store_n(&cover[0], 0, __ATOMIC_RELAXED);
+	/* That's the target syscal call. */
+	read(-1, NULL, 0);
+	/* Read number of PCs collected. */
+	n = __atomic_load_n(&cover[0], __ATOMIC_RELAXED);
+	for (i = 0; i < n; i++)
+		printf("0x%lx\n", cover[i + 1]);
+	/* Disable coverage collection for the current thread. After this call
+	 * coverage can be enabled for a different thread.
+	 */
+	if (ioctl(fd, KCOV_DISABLE, 0))
+		perror("ioctl"), exit(1);
+	/* Free resources. */
+	if (munmap(cover, COVER_SIZE * sizeof(unsigned long)))
+		perror("munmap"), exit(1);
+	if (close(fd))
+		perror("close"), exit(1);
+	return 0;
+}
+
+After piping through addr2line output of the program looks as follows:
+
+SyS_read
+fs/read_write.c:562
+__fdget_pos
+fs/file.c:774
+__fget_light
+fs/file.c:746
+__fget_light
+fs/file.c:750
+__fget_light
+fs/file.c:760
+__fdget_pos
+fs/file.c:784
+SyS_read
+fs/read_write.c:562
+
+If a program needs to collect coverage from several threads (independently),
+it needs to open /sys/kernel/debug/kcov in each thread separately.
+
+The interface is fine-grained to allow efficient forking of test processes.
+That is, a parent process opens /sys/kernel/debug/kcov, enables trace mode,
+mmaps coverage buffer and then forks child processes in a loop. Child processes
+only need to enable coverage (disable happens automatically on thread end).
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index bb8329c52298..3065f625a01e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2535,8 +2535,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	nointroute	[IA-64]
 
+	noinvpcid	[X86] Disable the INVPCID cpu feature.
+
 	nojitter	[IA-64] Disables jitter checking for ITC timers.
 
+	nopti		[X86-64] Disable KAISER isolation of kernel from user.
+
 	no-kvmclock	[X86,KVM] Disable paravirtualized KVM clock driver
 
 	no-kvmapf	[X86,KVM] Disable paravirtualized asynchronous page
@@ -2569,6 +2573,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	nopat		[X86] Disable PAT (page attribute table extension of
 			pagetables) support.
 
+	nopcid		[X86-64] Disable the PCID cpu feature.
+
 	norandmaps	Don't use address space randomization.  Equivalent to
 			echo 0 > /proc/sys/kernel/randomize_va_space
 
@@ -3071,6 +3077,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	pt.		[PARIDE]
 			See Documentation/blockdev/paride.txt.
 
+	pti=		[X86_64]
+			Control KAISER user/kernel address space isolation:
+			on - enable
+			off - disable
+			auto - default setting
+
 	pty.legacy_count=
 			[KNL] Number of legacy pty's. Overwrites compiled-in
 			default number.