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;