diff options
| -rw-r--r-- | Documentation/fault-injection/fault-injection.txt | 12 | ||||
| -rw-r--r-- | include/linux/fault-inject.h | 12 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 5 | ||||
| -rw-r--r-- | lib/fault-inject.c | 126 |
4 files changed, 150 insertions, 5 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt index cf075c20eda0..6d6e5ac5ea92 100644 --- a/Documentation/fault-injection/fault-injection.txt +++ b/Documentation/fault-injection/fault-injection.txt @@ -73,13 +73,17 @@ configuration of fault-injection capabilities. Any positive value limits failures to only processes indicated by /proc/<pid>/make-it-fail==1. -- /debug/*/address-start: -- /debug/*/address-end: +- /debug/*/require-start: +- /debug/*/require-end: +- /debug/*/reject-start: +- /debug/*/reject-end: specifies the range of virtual addresses tested during stacktrace walking. Failure is injected only if some caller - in the walked stacktrace lies within this range. - Default is [0,ULONG_MAX) (whole of virtual address space). + in the walked stacktrace lies within the required range, and + none lies within the rejected range. + Default required range is [0,ULONG_MAX) (whole of virtual address space). + Default rejected range is [0,0). - /debug/*/stacktrace-depth: diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h index a525f9b9f015..9bb584e89399 100644 --- a/include/linux/fault-inject.h +++ b/include/linux/fault-inject.h @@ -18,6 +18,11 @@ struct fault_attr { atomic_t space; unsigned long verbose; u32 task_filter; + unsigned long stacktrace_depth; + unsigned long require_start; + unsigned long require_end; + unsigned long reject_start; + unsigned long reject_end; unsigned long count; @@ -32,6 +37,11 @@ struct fault_attr { struct dentry *space_file; struct dentry *verbose_file; struct dentry *task_filter_file; + struct dentry *stacktrace_depth_file; + struct dentry *require_start_file; + struct dentry *require_end_file; + struct dentry *reject_start_file; + struct dentry *reject_end_file; } dentries; #endif @@ -40,6 +50,8 @@ struct fault_attr { #define FAULT_ATTR_INITIALIZER { \ .interval = 1, \ .times = ATOMIC_INIT(1), \ + .require_end = ULONG_MAX, \ + .stacktrace_depth = 32, \ } #define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 336241bf0ced..1449ca1bf572 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -416,6 +416,11 @@ config LKDTM config FAULT_INJECTION bool + select STACKTRACE + select FRAME_POINTER + help + Provide fault-injection framework. + For more details, see Documentation/fault-injection/. config FAILSLAB bool "Fault-injection capabilitiy for kmalloc" diff --git a/lib/fault-inject.c b/lib/fault-inject.c index 03468609d701..361c6e9cd77f 100644 --- a/lib/fault-inject.c +++ b/lib/fault-inject.c @@ -6,6 +6,9 @@ #include <linux/fs.h> #include <linux/module.h> #include <linux/interrupt.h> +#include <linux/unwind.h> +#include <linux/stacktrace.h> +#include <linux/kallsyms.h> #include <linux/fault-inject.h> /* @@ -50,6 +53,86 @@ static int fail_task(struct fault_attr *attr, struct task_struct *task) return !in_interrupt() && task->make_it_fail; } +#ifdef CONFIG_STACK_UNWIND + +static asmlinkage int fail_stacktrace_callback(struct unwind_frame_info *info, + void *arg) +{ + int depth; + struct fault_attr *attr = arg; + bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX); + + for (depth = 0; depth < attr->stacktrace_depth + && unwind(info) == 0 && UNW_PC(info); depth++) { + if (arch_unw_user_mode(info)) + break; + if (attr->reject_start <= UNW_PC(info) && + UNW_PC(info) < attr->reject_end) + return 0; + if (attr->require_start <= UNW_PC(info) && + UNW_PC(info) < attr->require_end) + found = 1; + } + return found; +} + +static int fail_stacktrace(struct fault_attr *attr) +{ + struct unwind_frame_info info; + + return unwind_init_running(&info, fail_stacktrace_callback, attr); +} + +#elif defined(CONFIG_STACKTRACE) + +#define MAX_STACK_TRACE_DEPTH 32 + +static int fail_stacktrace(struct fault_attr *attr) +{ + struct stack_trace trace; + int depth = attr->stacktrace_depth; + unsigned long entries[MAX_STACK_TRACE_DEPTH]; + int n; + bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX); + + if (depth == 0) + return found; + + trace.nr_entries = 0; + trace.entries = entries; + trace.max_entries = (depth < MAX_STACK_TRACE_DEPTH) ? + depth : MAX_STACK_TRACE_DEPTH; + trace.skip = 1; + trace.all_contexts = 0; + + save_stack_trace(&trace, NULL); + for (n = 0; n < trace.nr_entries; n++) { + if (attr->reject_start <= entries[n] && + entries[n] < attr->reject_end) + return 0; + if (attr->require_start <= entries[n] && + entries[n] < attr->require_end) + found = 1; + } + return found; +} + +#else + +static inline int fail_stacktrace(struct fault_attr *attr) +{ + static int firsttime = 1; + + if (firsttime) { + printk(KERN_WARNING + "This architecture does not implement save_stack_trace()\n"); + firsttime = 0; + } + return 0; +} + +#endif + /* * This code is stolen from failmalloc-1.0 * http://www.nongnu.org/failmalloc/ @@ -60,6 +143,9 @@ int should_fail(struct fault_attr *attr, ssize_t size) if (attr->task_filter && !fail_task(attr, current)) return 0; + if (!fail_stacktrace(attr)) + return 0; + if (atomic_read(&attr->times) == 0) return 0; @@ -147,6 +233,21 @@ void cleanup_fault_attr_dentries(struct fault_attr *attr) debugfs_remove(attr->dentries.task_filter_file); attr->dentries.task_filter_file = NULL; + debugfs_remove(attr->dentries.stacktrace_depth_file); + attr->dentries.stacktrace_depth_file = NULL; + + debugfs_remove(attr->dentries.require_start_file); + attr->dentries.require_start_file = NULL; + + debugfs_remove(attr->dentries.require_end_file); + attr->dentries.require_end_file = NULL; + + debugfs_remove(attr->dentries.reject_start_file); + attr->dentries.reject_start_file = NULL; + + debugfs_remove(attr->dentries.reject_end_file); + attr->dentries.reject_end_file = NULL; + if (attr->dentries.dir) WARN_ON(!simple_empty(attr->dentries.dir)); @@ -184,9 +285,32 @@ int init_fault_attr_dentries(struct fault_attr *attr, const char *name) attr->dentries.task_filter_file = debugfs_create_bool("task-filter", mode, dir, &attr->task_filter); + attr->dentries.stacktrace_depth_file = + debugfs_create_ul("stacktrace-depth", mode, dir, + &attr->stacktrace_depth); + + attr->dentries.require_start_file = + debugfs_create_ul("require-start", mode, dir, &attr->require_start); + + attr->dentries.require_end_file = + debugfs_create_ul("require-end", mode, dir, &attr->require_end); + + attr->dentries.reject_start_file = + debugfs_create_ul("reject-start", mode, dir, &attr->reject_start); + + attr->dentries.reject_end_file = + debugfs_create_ul("reject-end", mode, dir, &attr->reject_end); + + if (!attr->dentries.probability_file || !attr->dentries.interval_file || !attr->dentries.times_file || !attr->dentries.space_file - || !attr->dentries.verbose_file || !attr->dentries.task_filter_file) + || !attr->dentries.verbose_file || !attr->dentries.task_filter_file + || !attr->dentries.stacktrace_depth_file + || !attr->dentries.require_start_file + || !attr->dentries.require_end_file + || !attr->dentries.reject_start_file + || !attr->dentries.reject_end_file + ) goto fail; return 0; |