This patch provides process filtering feature.
Example:
# modprobe should_fail_knobs
# echo 1 > /debug/failslab/process-filter
# echo 30 > /debug/failslab/probability
# find /lib/modules/`uname -r` -name '*.ko' -exec basename {} .ko \; > list
# for i in `cat list`;do failmodprobe $i;done
failmodprobe:
-------------
#!/bin/bash
echo 1 > /proc/self/make-it-fail
exec modprobe $*
Signed-off-by: Akinobu Mita <[email protected]>
fs/proc/base.c | 77 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/sched.h | 3 +
include/linux/should_fail.h | 3 +
lib/should_fail.c | 11 ++++--
lib/should_fail_knobs.c | 10 +++++
5 files changed, 101 insertions(+), 3 deletions(-)
Index: work-shouldfail/fs/proc/base.c
===================================================================
--- work-shouldfail.orig/fs/proc/base.c
+++ work-shouldfail/fs/proc/base.c
@@ -138,6 +138,9 @@ enum pid_directory_inos {
#endif
PROC_TGID_OOM_SCORE,
PROC_TGID_OOM_ADJUST,
+#ifdef CONFIG_SHOULD_FAIL
+ PROC_TGID_SHOULD_FAIL,
+#endif
PROC_TID_INO,
PROC_TID_STATUS,
PROC_TID_MEM,
@@ -181,6 +184,9 @@ enum pid_directory_inos {
#endif
PROC_TID_OOM_SCORE,
PROC_TID_OOM_ADJUST,
+#ifdef CONFIG_SHOULD_FAIL
+ PROC_TID_SHOULD_FAIL,
+#endif
/* Add new entries before this */
PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
@@ -240,6 +246,9 @@ static struct pid_entry tgid_base_stuff[
#ifdef CONFIG_AUDITSYSCALL
E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
#endif
+#ifdef CONFIG_SHOULD_FAIL
+ E(PROC_TGID_SHOULD_FAIL, "make-it-fail", S_IFREG|S_IWUSR|S_IRUGO),
+#endif
{0,0,NULL,0}
};
static struct pid_entry tid_base_stuff[] = {
@@ -282,6 +291,9 @@ static struct pid_entry tid_base_stuff[]
#ifdef CONFIG_AUDITSYSCALL
E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
#endif
+#ifdef CONFIG_SHOULD_FAIL
+ E(PROC_TID_SHOULD_FAIL, "make-it-fail", S_IFREG|S_IWUSR|S_IRUGO),
+#endif
{0,0,NULL,0}
};
@@ -992,6 +1004,65 @@ static struct file_operations proc_login
};
#endif
+#ifdef CONFIG_SHOULD_FAIL
+static ssize_t proc_should_fail_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
+ char buffer[PROC_NUMBUF];
+ size_t len;
+ int make_it_fail;
+ loff_t __ppos = *ppos;
+
+ if (!task)
+ return -ESRCH;
+ make_it_fail = task->make_it_fail;
+ put_task_struct(task);
+
+ len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
+ if (__ppos >= len)
+ return 0;
+ if (count > len-__ppos)
+ count = len-__ppos;
+ if (copy_to_user(buf, buffer + __ppos, count))
+ return -EFAULT;
+ *ppos = __ppos + count;
+ return count;
+}
+
+static ssize_t proc_should_fail_write(struct file * file,
+ const char __user * buf, size_t count, loff_t *ppos)
+{
+ struct task_struct *task;
+ char buffer[PROC_NUMBUF], *end;
+ int make_it_fail;
+
+ if (!capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1)
+ count = sizeof(buffer) - 1;
+ if (copy_from_user(buffer, buf, count))
+ return -EFAULT;
+ make_it_fail = simple_strtol(buffer, &end, 0);
+ if (*end == '\n')
+ end++;
+ task = get_proc_task(file->f_dentry->d_inode);
+ if (!task)
+ return -ESRCH;
+ task->make_it_fail = make_it_fail;
+ put_task_struct(task);
+ if (end - buffer == 0)
+ return -EIO;
+ return end - buffer;
+}
+
+static struct file_operations proc_should_fail_operations = {
+ .read = proc_should_fail_read,
+ .write = proc_should_fail_write,
+};
+#endif
+
#ifdef CONFIG_SECCOMP
static ssize_t seccomp_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
@@ -1834,6 +1905,12 @@ static struct dentry *proc_pident_lookup
inode->i_fop = &proc_loginuid_operations;
break;
#endif
+#ifdef CONFIG_SHOULD_FAIL
+ case PROC_TID_SHOULD_FAIL:
+ case PROC_TGID_SHOULD_FAIL:
+ inode->i_fop = &proc_should_fail_operations;
+ break;
+#endif
default:
printk("procfs: impossible type (%d)",p->type);
iput(inode);
Index: work-shouldfail/include/linux/sched.h
===================================================================
--- work-shouldfail.orig/include/linux/sched.h
+++ work-shouldfail/include/linux/sched.h
@@ -997,6 +997,9 @@ struct task_struct {
spinlock_t delays_lock;
struct task_delay_info *delays;
#endif
+#ifdef CONFIG_SHOULD_FAIL
+ int make_it_fail;
+#endif
};
static inline pid_t process_group(struct task_struct *tsk)
Index: work-shouldfail/include/linux/should_fail.h
===================================================================
--- work-shouldfail.orig/include/linux/should_fail.h
+++ work-shouldfail/include/linux/should_fail.h
@@ -27,6 +27,9 @@ struct should_fail_data {
atomic_t space;
unsigned long count;
+
+ /* process filter */
+ unsigned long process_filter;
};
#define DEFINE_SHOULD_FAIL(name) \
Index: work-shouldfail/lib/should_fail.c
===================================================================
--- work-shouldfail.orig/lib/should_fail.c
+++ work-shouldfail/lib/should_fail.c
@@ -13,16 +13,18 @@ int setup_should_fail(struct should_fail
unsigned long interval;
int times;
int space;
+ unsigned long filter;
- /* "<probability>,<interval>,<times>,<space>" */
- if (sscanf(str, "%lu,%lu,%d,%d", &probability, &interval, ×,
- &space) < 4)
+ /* "<probability>,<interval>,<times>,<space>,<process-filter>" */
+ if (sscanf(str, "%lu,%lu,%d,%d,%d", &probability, &interval, ×,
+ &space, &filter) < 5)
return 0;
data->probability = probability;
data->interval = interval;
atomic_set(&data->times, times);
atomic_set(&data->space, space);
+ data->process_filter = filter;
return 1;
}
@@ -54,6 +56,9 @@ void should_fail_srandom(unsigned long e
int should_fail(struct should_fail_data *data, ssize_t size)
{
+ if (data->process_filter && !current->make_it_fail)
+ return 0;
+
if (atomic_read(&max_failures(data)) == 0)
return 0;
Index: work-shouldfail/lib/should_fail_knobs.c
===================================================================
--- work-shouldfail.orig/lib/should_fail_knobs.c
+++ work-shouldfail/lib/should_fail_knobs.c
@@ -8,6 +8,7 @@ struct should_fail_knobs {
struct dentry *interval_file;
struct dentry *times_file;
struct dentry *space_file;
+ struct dentry *filter_file;
};
static void debugfs_ul_set(void *data, u64 val)
@@ -66,6 +67,10 @@ static void cleanup_should_fail_knobs(st
debugfs_remove(knobs->space_file);
knobs->space_file = NULL;
}
+ if (knobs->filter_file) {
+ debugfs_remove(knobs->filter_file);
+ knobs->filter_file = NULL;
+ }
debugfs_remove(knobs->dir);
knobs->dir = NULL;
}
@@ -105,6 +110,11 @@ static int init_should_fail_knobs(struct
goto fail;
knobs->space_file = file;
+ file = debugfs_create_ul("process-filter", mode, dir, &data->process_filter);
+ if (!file)
+ goto fail;
+ knobs->filter_file = file;
+
return 0;
fail:
cleanup_should_fail_knobs(knobs);
--