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authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 17:25:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 17:25:34 -0700
commit27c1ee3f929555b71fa39ec0d81a7e7185de1b16 (patch)
tree42e40bdfe4efac660d650658019391536ce67a42 /Documentation
parent37cd9600a9e20359b0283983c9e3a55d84347168 (diff)
parent086ff4b3a7fb9cdf41e6a5d0ccd99b86d84633a1 (diff)
Merge branch 'akpm' (Andrew's patch-bomb)
Merge Andrew's first set of patches: "Non-MM patches: - lots of misc bits - tree-wide have_clk() cleanups - quite a lot of printk tweaks. I draw your attention to "printk: convert the format for KERN_<LEVEL> to a 2 byte pattern" which looks a bit scary. But afaict it's solid. - backlight updates - lib/ feature work (notably the addition and use of memweight()) - checkpatch updates - rtc updates - nilfs updates - fatfs updates (partial, still waiting for acks) - kdump, proc, fork, IPC, sysctl, taskstats, pps, etc - new fault-injection feature work" * Merge emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits) drivers/misc/lkdtm.c: fix missing allocation failure check lib/scatterlist: do not re-write gfp_flags in __sg_alloc_table() fault-injection: add tool to run command with failslab or fail_page_alloc fault-injection: add selftests for cpu and memory hotplug powerpc: pSeries reconfig notifier error injection module memory: memory notifier error injection module PM: PM notifier error injection module cpu: rewrite cpu-notifier-error-inject module fault-injection: notifier error injection c/r: fcntl: add F_GETOWNER_UIDS option resource: make sure requested range is included in the root range include/linux/aio.h: cpp->C conversions fs: cachefiles: add support for large files in filesystem caching pps: return PTR_ERR on error in device_create taskstats: check nla_reserve() return sysctl: suppress kmemleak messages ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION ipc: compat: use signed size_t types for msgsnd and msgrcv ipc: allow compat IPC version field parsing if !ARCH_WANT_OLD_COMPAT_IPC ipc: add COMPAT_SHMLBA support ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/fault-injection/fault-injection.txt27
-rw-r--r--Documentation/fault-injection/notifier-error-inject.txt99
-rw-r--r--Documentation/printk-formats.txt15
-rw-r--r--Documentation/sysctl/fs.txt18
4 files changed, 153 insertions, 6 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index ba4be8b7709..4cf1a2a6bd7 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -240,3 +240,30 @@ trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
echo "Injecting errors into the module $module... (interrupt to stop)"
sleep 1000000
+Tool to run command with failslab or fail_page_alloc
+----------------------------------------------------
+In order to make it easier to accomplish the tasks mentioned above, we can use
+tools/testing/fault-injection/failcmd.sh. Please run a command
+"./tools/testing/fault-injection/failcmd.sh --help" for more information and
+see the following examples.
+
+Examples:
+
+Run a command "make -C tools/testing/selftests/ run_tests" with injecting slab
+allocation failure.
+
+ # ./tools/testing/fault-injection/failcmd.sh \
+ -- make -C tools/testing/selftests/ run_tests
+
+Same as above except to specify 100 times failures at most instead of one time
+at most by default.
+
+ # ./tools/testing/fault-injection/failcmd.sh --times=100 \
+ -- make -C tools/testing/selftests/ run_tests
+
+Same as above except to inject page allocation failure instead of slab
+allocation failure.
+
+ # env FAILCMD_TYPE=fail_page_alloc \
+ ./tools/testing/fault-injection/failcmd.sh --times=100 \
+ -- make -C tools/testing/selftests/ run_tests
diff --git a/Documentation/fault-injection/notifier-error-inject.txt b/Documentation/fault-injection/notifier-error-inject.txt
new file mode 100644
index 00000000000..c83526c364e
--- /dev/null
+++ b/Documentation/fault-injection/notifier-error-inject.txt
@@ -0,0 +1,99 @@
+Notifier error injection
+========================
+
+Notifier error injection provides the ability to inject artifical errors to
+specified notifier chain callbacks. It is useful to test the error handling of
+notifier call chain failures which is rarely executed. There are kernel
+modules that can be used to test the following notifiers.
+
+ * CPU notifier
+ * PM notifier
+ * Memory hotplug notifier
+ * powerpc pSeries reconfig notifier
+
+CPU notifier error injection module
+-----------------------------------
+This feature can be used to test the error handling of the CPU notifiers by
+injecting artifical errors to CPU notifier chain callbacks.
+
+If the notifier call chain should be failed with some events notified, write
+the error code to debugfs interface
+/sys/kernel/debug/notifier-error-inject/cpu/actions/<notifier event>/error
+
+Possible CPU notifier events to be failed are:
+
+ * CPU_UP_PREPARE
+ * CPU_UP_PREPARE_FROZEN
+ * CPU_DOWN_PREPARE
+ * CPU_DOWN_PREPARE_FROZEN
+
+Example1: Inject CPU offline error (-1 == -EPERM)
+
+ # cd /sys/kernel/debug/notifier-error-inject/cpu
+ # echo -1 > actions/CPU_DOWN_PREPARE/error
+ # echo 0 > /sys/devices/system/cpu/cpu1/online
+ bash: echo: write error: Operation not permitted
+
+Example2: inject CPU online error (-2 == -ENOENT)
+
+ # echo -2 > actions/CPU_UP_PREPARE/error
+ # echo 1 > /sys/devices/system/cpu/cpu1/online
+ bash: echo: write error: No such file or directory
+
+PM notifier error injection module
+----------------------------------
+This feature is controlled through debugfs interface
+/sys/kernel/debug/notifier-error-inject/pm/actions/<notifier event>/error
+
+Possible PM notifier events to be failed are:
+
+ * PM_HIBERNATION_PREPARE
+ * PM_SUSPEND_PREPARE
+ * PM_RESTORE_PREPARE
+
+Example: Inject PM suspend error (-12 = -ENOMEM)
+
+ # cd /sys/kernel/debug/notifier-error-inject/pm/
+ # echo -12 > actions/PM_SUSPEND_PREPARE/error
+ # echo mem > /sys/power/state
+ bash: echo: write error: Cannot allocate memory
+
+Memory hotplug notifier error injection module
+----------------------------------------------
+This feature is controlled through debugfs interface
+/sys/kernel/debug/notifier-error-inject/memory/actions/<notifier event>/error
+
+Possible memory notifier events to be failed are:
+
+ * MEM_GOING_ONLINE
+ * MEM_GOING_OFFLINE
+
+Example: Inject memory hotplug offline error (-12 == -ENOMEM)
+
+ # cd /sys/kernel/debug/notifier-error-inject/memory
+ # echo -12 > actions/MEM_GOING_OFFLINE/error
+ # echo offline > /sys/devices/system/memory/memoryXXX/state
+ bash: echo: write error: Cannot allocate memory
+
+powerpc pSeries reconfig notifier error injection module
+--------------------------------------------------------
+This feature is controlled through debugfs interface
+/sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions/<notifier event>/error
+
+Possible pSeries reconfig notifier events to be failed are:
+
+ * PSERIES_RECONFIG_ADD
+ * PSERIES_RECONFIG_REMOVE
+ * PSERIES_DRCONF_MEM_ADD
+ * PSERIES_DRCONF_MEM_REMOVE
+
+For more usage examples
+-----------------------
+There are tools/testing/selftests using the notifier error injection features
+for CPU and memory notifiers.
+
+ * tools/testing/selftests/cpu-hotplug/on-off-test.sh
+ * tools/testing/selftests/memory-hotplug/on-off-test.sh
+
+These scripts first do simple online and offline tests and then do fault
+injection tests if notifier error injection module is available.
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 5df176ed59b..7561d7ed8e1 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -53,9 +53,20 @@ Struct Resources:
For printing struct resources. The 'R' and 'r' specifiers result in a
printed resource with ('R') or without ('r') a decoded flags member.
+Raw buffer as a hex string:
+ %*ph 00 01 02 ... 3f
+ %*phC 00:01:02: ... :3f
+ %*phD 00-01-02- ... -3f
+ %*phN 000102 ... 3f
+
+ For printing a small buffers (up to 64 bytes long) as a hex string with
+ certain separator. For the larger buffers consider to use
+ print_hex_dump().
+
MAC/FDDI addresses:
%pM 00:01:02:03:04:05
+ %pMR 05:04:03:02:01:00
%pMF 00-01-02-03-04-05
%pm 000102030405
@@ -67,6 +78,10 @@ MAC/FDDI addresses:
the 'M' specifier to use dash ('-') separators instead of the default
separator.
+ For Bluetooth addresses the 'R' specifier shall be used after the 'M'
+ specifier to use reversed byte order suitable for visual interpretation
+ of Bluetooth addresses which are in the little endian order.
+
IPv4 addresses:
%pI4 1.2.3.4
diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt
index 13d6166d7a2..8c235b6e424 100644
--- a/Documentation/sysctl/fs.txt
+++ b/Documentation/sysctl/fs.txt
@@ -163,16 +163,22 @@ This value can be used to query and set the core dump mode for setuid
or otherwise protected/tainted binaries. The modes are
0 - (default) - traditional behaviour. Any process which has changed
- privilege levels or is execute only will not be dumped
+ privilege levels or is execute only will not be dumped.
1 - (debug) - all processes dump core when possible. The core dump is
owned by the current user and no security is applied. This is
intended for system debugging situations only. Ptrace is unchecked.
+ This is insecure as it allows regular users to examine the memory
+ contents of privileged processes.
2 - (suidsafe) - any binary which normally would not be dumped is dumped
- readable by root only. This allows the end user to remove
- such a dump but not access it directly. For security reasons
- core dumps in this mode will not overwrite one another or
- other files. This mode is appropriate when administrators are
- attempting to debug problems in a normal environment.
+ anyway, but only if the "core_pattern" kernel sysctl is set to
+ either a pipe handler or a fully qualified path. (For more details
+ on this limitation, see CVE-2006-2451.) This mode is appropriate
+ when administrators are attempting to debug problems in a normal
+ environment, and either have a core dump pipe handler that knows
+ to treat privileged core dumps with care, or specific directory
+ defined for catching core dumps. If a core dump happens without
+ a pipe handler or fully qualifid path, a message will be emitted
+ to syslog warning about the lack of a correct setting.
==============================================================