Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix WARN_ON() test for UP
  WARN_ON_SMP(): Allow use in if() statements on UP
  x86, dumpstack: Use %pB format specifier for stack trace
  vsprintf: Introduce %pB format specifier
  lockdep: Remove unused 'factor' variable from lockdep_stats_show()

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 81ac6c7..e2a3f06 100644 (file)
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -27,7 +27,7 @@ static int die_counter;
 
 void printk_address(unsigned long address, int reliable)
 {
-       printk(" [<%p>] %s%pS\n", (void *) address,
+       printk(" [<%p>] %s%pB\n", (void *) address,
                        reliable ? "" : "? ", (void *) address);
 }
 

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index c2c9ba0..f2d2faf 100644 (file)
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -165,10 +165,36 @@ extern void warn_slowpath_null(const char *file, const int line);
 #define WARN_ON_RATELIMIT(condition, state)                    \
                WARN_ON((condition) && __ratelimit(state))
 
+/*
+ * WARN_ON_SMP() is for cases that the warning is either
+ * meaningless for !SMP or may even cause failures.
+ * This is usually used for cases that we have
+ * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
+ * returns 0 for uniprocessor settings.
+ * It can also be used with values that are only defined
+ * on SMP:
+ *
+ * struct foo {
+ *  [...]
+ * #ifdef CONFIG_SMP
+ *     int bar;
+ * #endif
+ * };
+ *
+ * void func(struct foo *zoot)
+ * {
+ *     WARN_ON_SMP(!zoot->bar);
+ *
+ * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
+ * and should be a nop and return false for uniprocessor.
+ *
+ * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
+ * and x is true.
+ */
 #ifdef CONFIG_SMP
 # define WARN_ON_SMP(x)                        WARN_ON(x)
 #else
-# define WARN_ON_SMP(x)                        do { } while (0)
+# define WARN_ON_SMP(x)                        ({0;})
 #endif
 
 #endif

diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index d8e9b3d..0df513b 100644 (file)
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -36,6 +36,7 @@ const char *kallsyms_lookup(unsigned long addr,
 
 /* Look up a kernel symbol and return it in a text buffer. */
 extern int sprint_symbol(char *buffer, unsigned long address);
+extern int sprint_backtrace(char *buffer, unsigned long address);
 
 /* Look up a kernel symbol and print it to the kernel messages. */
 extern void __print_symbol(const char *fmt, unsigned long address);
@@ -79,6 +80,12 @@ static inline int sprint_symbol(char *buffer, unsigned long addr)
        return 0;
 }
 
+static inline int sprint_backtrace(char *buffer, unsigned long addr)
+{
+       *buffer = '\0';
+       return 0;
+}
+
 static inline int lookup_symbol_name(unsigned long addr, char *symname)
 {
        return -ERANGE;

diff --git a/kernel/futex.c b/kernel/futex.c
index 6570c45..dfb924f 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -782,8 +782,8 @@ static void __unqueue_futex(struct futex_q *q)
 {
        struct futex_hash_bucket *hb;
 
-       if (WARN_ON(!q->lock_ptr || !spin_is_locked(q->lock_ptr)
-                       || plist_node_empty(&q->list)))
+       if (WARN_ON_SMP(!q->lock_ptr || !spin_is_locked(q->lock_ptr))
+           || WARN_ON(plist_node_empty(&q->list)))
                return;
 
        hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock);

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a56aa58..079f1d3 100644 (file)
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -342,13 +342,15 @@ int lookup_symbol_attrs(unsigned long addr, unsigned long *size,
 }
 
 /* Look up a kernel symbol and return it in a text buffer. */
-int sprint_symbol(char *buffer, unsigned long address)
+static int __sprint_symbol(char *buffer, unsigned long address,
+                          int symbol_offset)
 {
        char *modname;
        const char *name;
        unsigned long offset, size;
        int len;
 
+       address += symbol_offset;
        name = kallsyms_lookup(address, &size, &offset, &modname, buffer);
        if (!name)
                return sprintf(buffer, "0x%lx", address);
@@ -357,17 +359,53 @@ int sprint_symbol(char *buffer, unsigned long address)
                strcpy(buffer, name);
        len = strlen(buffer);
        buffer += len;
+       offset -= symbol_offset;
 
        if (modname)
-               len += sprintf(buffer, "+%#lx/%#lx [%s]",
-                                               offset, size, modname);
+               len += sprintf(buffer, "+%#lx/%#lx [%s]", offset, size, modname);
        else
                len += sprintf(buffer, "+%#lx/%#lx", offset, size);
 
        return len;
 }
+
+/**
+ * sprint_symbol - Look up a kernel symbol and return it in a text buffer
+ * @buffer: buffer to be stored
+ * @address: address to lookup
+ *
+ * This function looks up a kernel symbol with @address and stores its name,
+ * offset, size and module name to @buffer if possible. If no symbol was found,
+ * just saves its @address as is.
+ *
+ * This function returns the number of bytes stored in @buffer.
+ */
+int sprint_symbol(char *buffer, unsigned long address)
+{
+       return __sprint_symbol(buffer, address, 0);
+}
+
 EXPORT_SYMBOL_GPL(sprint_symbol);
 
+/**
+ * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer
+ * @buffer: buffer to be stored
+ * @address: address to lookup
+ *
+ * This function is for stack backtrace and does the same thing as
+ * sprint_symbol() but with modified/decreased @address. If there is a
+ * tail-call to the function marked "noreturn", gcc optimized out code after
+ * the call so that the stack-saved return address could point outside of the
+ * caller. This function ensures that kallsyms will find the original caller
+ * by decreasing @address.
+ *
+ * This function returns the number of bytes stored in @buffer.
+ */
+int sprint_backtrace(char *buffer, unsigned long address)
+{
+       return __sprint_symbol(buffer, address, -1);
+}
+
 /* Look up a kernel symbol and print it to the kernel messages. */
 void __print_symbol(const char *fmt, unsigned long address)
 {

diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 1969d2f..71edd2f 100644 (file)
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -225,7 +225,7 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
                      nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
                      nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
                      nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
-                     sum_forward_deps = 0, factor = 0;
+                     sum_forward_deps = 0;
 
        list_for_each_entry(class, &all_lock_classes, lock_entry) {
 
@@ -283,13 +283,6 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
                        nr_hardirq_unsafe * nr_hardirq_safe +
                        nr_list_entries);
 
-       /*
-        * Estimated factor between direct and indirect
-        * dependencies:
-        */
-       if (nr_list_entries)
-               factor = sum_forward_deps / nr_list_entries;
-
 #ifdef CONFIG_PROVE_LOCKING
        seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
                        nr_lock_chains, MAX_LOCKDEP_CHAINS);

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 02bcdd5..bc0ac6b 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -433,7 +433,9 @@ char *symbol_string(char *buf, char *end, void *ptr,
        unsigned long value = (unsigned long) ptr;
 #ifdef CONFIG_KALLSYMS
        char sym[KSYM_SYMBOL_LEN];
-       if (ext != 'f' && ext != 's')
+       if (ext == 'B')
+               sprint_backtrace(sym, value);
+       else if (ext != 'f' && ext != 's')
                sprint_symbol(sym, value);
        else
                kallsyms_lookup(value, NULL, NULL, NULL, sym);
@@ -808,6 +810,7 @@ int kptr_restrict = 1;
  * - 'f' For simple symbolic function names without offset
  * - 'S' For symbolic direct pointers with offset
  * - 's' For symbolic direct pointers without offset
+ * - 'B' For backtraced symbolic direct pointers with offset
  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
  * - 'M' For a 6-byte MAC address, it prints the address in the
@@ -867,6 +870,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
                /* Fallthrough */
        case 'S':
        case 's':
+       case 'B':
                return symbol_string(buf, end, ptr, spec, *fmt);
        case 'R':
        case 'r':
@@ -1134,6 +1138,7 @@ qualifier:
  * %ps output the name of a text symbol without offset
  * %pF output the name of a function pointer with its offset
  * %pf output the name of a function pointer without its offset
+ * %pB output the name of a backtrace symbol with its offset
  * %pR output the address range in a struct resource with decoded flags
  * %pr output the address range in a struct resource with raw flags
  * %pM output a 6-byte MAC address with colons