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authorLinus Torvalds2017-07-14 21:57:25 -0700
committerLinus Torvalds2017-07-14 21:57:25 -0700
commit867eacd7fb975273703766f52f485f08471a1ae9 (patch)
treebe3c024c940d34331d5329a61a8e2be64f21da17 /Documentation
parent077d2ba519b2e8bf1abd80cbade699b1de42cafe (diff)
parent6d7964a722afc8e4f880b947f174009063028c99 (diff)
Merge branch 'akpm' (patches from Andrew)
Merge even more updates from Andrew Morton: - a few leftovers - fault-injector rework - add a module loader test driver * emailed patches from Andrew Morton <akpm@linux-foundation.org>: kmod: throttle kmod thread limit kmod: add test driver to stress test the module loader MAINTAINERS: give kmod some maintainer love xtensa: use generic fb.h fault-inject: add /proc/<pid>/fail-nth fault-inject: simplify access check for fail-nth fault-inject: make fail-nth read/write interface symmetric fault-inject: parse as natural 1-based value for fail-nth write interface fault-inject: automatically detect the number base for fail-nth write interface kernel/watchdog.c: use better pr_fmt prefix MAINTAINERS: move the befs tree to kernel.org lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int mm: fix overflow check in expand_upwards()
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/fault-injection/fault-injection.txt21
1 files changed, 11 insertions, 10 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index 192d8cbcc5f9..918972babcd8 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -136,12 +136,13 @@ use the boot option:
o proc entries
-- /proc/self/task/<current-tid>/fail-nth:
+- /proc/<pid>/fail-nth:
+- /proc/self/task/<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.
+ Write to this file of integer N makes N-th call in the task fail.
+ Read from this file returns a integer value. A value of '0' indicates
+ that the fault setup with a previous write to this file was injected.
+ A positive integer N indicates that the fault 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
@@ -320,18 +321,19 @@ int main()
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++) {
+ for (i = 1;; 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);
+ pread(fail_nth, buf, sizeof(buf), 0);
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')
+ printf("%d-th fault %c: res=%d/%d\n", i, atoi(buf) ? 'N' : 'Y',
+ res, err);
+ if (atoi(buf))
break;
}
return 0;
@@ -339,7 +341,6 @@ int main()
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