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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-13 12:38:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-13 12:38:49 -0700
commitad51271afc21a72479974713abb40ca4b96d1f6b (patch)
treee4281fa72a0bfbb08918e10546bdb6abe123f974 /Documentation
parentMerge tag 'platform-drivers-x86-v4.13-2' of git://git.infradead.org/linux-platform-drivers-x86 (diff)
parentwriteback: rework wb_[dec|inc]_stat family of functions (diff)
downloadwireguard-linux-ad51271afc21a72479974713abb40ca4b96d1f6b.tar.xz
wireguard-linux-ad51271afc21a72479974713abb40ca4b96d1f6b.zip
Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton: - various misc things - kexec updates - sysctl core updates - scripts/gdb udpates - checkpoint-restart updates - ipc updates - kernel/watchdog updates - Kees's "rough equivalent to the glibc _FORTIFY_SOURCE=1 feature" - "stackprotector: ascii armor the stack canary" - more MM bits - checkpatch updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits) writeback: rework wb_[dec|inc]_stat family of functions ARM: samsung: usb-ohci: move inline before return type video: fbdev: omap: move inline before return type video: fbdev: intelfb: move inline before return type USB: serial: safe_serial: move __inline__ before return type drivers: tty: serial: move inline before return type drivers: s390: move static and inline before return type x86/efi: move asmlinkage before return type sh: move inline before return type MIPS: SMP: move asmlinkage before return type m68k: coldfire: move inline before return type ia64: sn: pci: move inline before type ia64: move inline before return type FRV: tlbflush: move asmlinkage before return type CRIS: gpio: move inline before return type ARM: HP Jornada 7XX: move inline before return type ARM: KVM: move asmlinkage before type checkpatch: improve the STORAGE_CLASS test mm, migration: do not trigger OOM killer when migrating memory drm/i915: use __GFP_RETRY_MAYFAIL ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DMA-ISA-LPC.txt2
-rw-r--r--Documentation/fault-injection/fault-injection.txt78
-rw-r--r--Documentation/filesystems/proc.txt6
-rw-r--r--Documentation/kdump/kdump.txt12
4 files changed, 93 insertions, 5 deletions
diff --git a/Documentation/DMA-ISA-LPC.txt b/Documentation/DMA-ISA-LPC.txt
index c41331398752..7a065ac4a9d1 100644
--- a/Documentation/DMA-ISA-LPC.txt
+++ b/Documentation/DMA-ISA-LPC.txt
@@ -42,7 +42,7 @@ requirements you pass the flag GFP_DMA to kmalloc.
Unfortunately the memory available for ISA DMA is scarce so unless you
allocate the memory during boot-up it's a good idea to also pass
-__GFP_REPEAT and __GFP_NOWARN to make the allocator try a bit harder.
+__GFP_RETRY_MAYFAIL and __GFP_NOWARN to make the allocator try a bit harder.
(This scarcity also means that you should allocate the buffer as
early as possible and not release it until the driver is unloaded.)
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index 415484f3d59a..192d8cbcc5f9 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -134,6 +134,22 @@ use the boot option:
fail_futex=
mmc_core.fail_request=<interval>,<probability>,<space>,<times>
+o proc entries
+
+- /proc/self/task/<current-tid>/fail-nth:
+
+ Write to this file of integer N makes N-th call in the current task fail
+ (N is 0-based). Read from this file returns a single char 'Y' or 'N'
+ that says if the fault setup with a previous write to this file was
+ injected or not, and disables the fault if it wasn't yet injected.
+ Note that this file enables all types of faults (slab, futex, etc).
+ This setting takes precedence over all other generic debugfs settings
+ like probability, interval, times, etc. But per-capability settings
+ (e.g. fail_futex/ignore-private) take precedence over it.
+
+ This feature is intended for systematic testing of faults in a single
+ system call. See an example below.
+
How to add new fault injection capability
-----------------------------------------
@@ -278,3 +294,65 @@ allocation failure.
# env FAILCMD_TYPE=fail_page_alloc \
./tools/testing/fault-injection/failcmd.sh --times=100 \
-- make -C tools/testing/selftests/ run_tests
+
+Systematic faults using fail-nth
+---------------------------------
+
+The following code systematically faults 0-th, 1-st, 2-nd and so on
+capabilities in the socketpair() system call.
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/syscall.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+
+int main()
+{
+ int i, err, res, fail_nth, fds[2];
+ char buf[128];
+
+ system("echo N > /sys/kernel/debug/failslab/ignore-gfp-wait");
+ sprintf(buf, "/proc/self/task/%ld/fail-nth", syscall(SYS_gettid));
+ fail_nth = open(buf, O_RDWR);
+ for (i = 0;; i++) {
+ sprintf(buf, "%d", i);
+ write(fail_nth, buf, strlen(buf));
+ res = socketpair(AF_LOCAL, SOCK_STREAM, 0, fds);
+ err = errno;
+ read(fail_nth, buf, 1);
+ if (res == 0) {
+ close(fds[0]);
+ close(fds[1]);
+ }
+ printf("%d-th fault %c: res=%d/%d\n", i, buf[0], res, err);
+ if (buf[0] != 'Y')
+ break;
+ }
+ return 0;
+}
+
+An example output:
+
+0-th fault Y: res=-1/23
+1-th fault Y: res=-1/23
+2-th fault Y: res=-1/23
+3-th fault Y: res=-1/12
+4-th fault Y: res=-1/12
+5-th fault Y: res=-1/23
+6-th fault Y: res=-1/23
+7-th fault Y: res=-1/23
+8-th fault Y: res=-1/12
+9-th fault Y: res=-1/12
+10-th fault Y: res=-1/12
+11-th fault Y: res=-1/12
+12-th fault Y: res=-1/12
+13-th fault Y: res=-1/12
+14-th fault Y: res=-1/12
+15-th fault Y: res=-1/12
+16-th fault N: res=0/12
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 4cddbce85ac9..adba21b5ada7 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1786,12 +1786,16 @@ pair provide additional information particular to the objects they represent.
pos: 0
flags: 02
mnt_id: 9
- tfd: 5 events: 1d data: ffffffffffffffff
+ tfd: 5 events: 1d data: ffffffffffffffff pos:0 ino:61af sdev:7
where 'tfd' is a target file descriptor number in decimal form,
'events' is events mask being watched and the 'data' is data
associated with a target [see epoll(7) for more details].
+ The 'pos' is current offset of the target file in decimal form
+ [see lseek(2)], 'ino' and 'sdev' are inode and device numbers
+ where target file resides, all in hex format.
+
Fsnotify files
~~~~~~~~~~~~~~
For inotify files the format is the following
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
index 615434d81108..51814450a7f8 100644
--- a/Documentation/kdump/kdump.txt
+++ b/Documentation/kdump/kdump.txt
@@ -112,8 +112,8 @@ There are two possible methods of using Kdump.
2) Or use the system kernel binary itself as dump-capture kernel and there is
no need to build a separate dump-capture kernel. This is possible
only with the architectures which support a relocatable kernel. As
- of today, i386, x86_64, ppc64, ia64 and arm architectures support relocatable
- kernel.
+ of today, i386, x86_64, ppc64, ia64, arm and arm64 architectures support
+ relocatable kernel.
Building a relocatable kernel is advantageous from the point of view that
one does not have to build a second kernel for capturing the dump. But
@@ -339,7 +339,7 @@ For arm:
For arm64:
- Use vmlinux or Image
-If you are using a uncompressed vmlinux image then use following command
+If you are using an uncompressed vmlinux image then use following command
to load dump-capture kernel.
kexec -p <dump-capture-kernel-vmlinux-image> \
@@ -361,6 +361,12 @@ to load dump-capture kernel.
--dtb=<dtb-for-dump-capture-kernel> \
--append="root=<root-dev> <arch-specific-options>"
+If you are using an uncompressed Image, then use following command
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"
Please note, that --args-linux does not need to be specified for ia64.
It is planned to make this a no-op on that architecture, but for now