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

…inux/kernel/git/tip/linux-2.6-tip

* '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()
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2 parents 26ff680 + 2909620 commit 94df491c4a01b39d81279a68386158eb02656712 @torvalds torvalds committed Mar 25, 2011
Showing with 85 additions and 16 deletions.
  1. +1 −1 arch/x86/kernel/dumpstack.c
  2. +27 −1 include/asm-generic/bug.h
  3. +7 −0 include/linux/kallsyms.h
  4. +2 −2 kernel/futex.c
  5. +41 −3 kernel/kallsyms.c
  6. +1 −8 kernel/lockdep_proc.c
  7. +6 −1 lib/vsprintf.c
View
2 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);
}
View
28 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
View
7 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;
View
4 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);
View
44 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)
{
View
9 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);
View
7 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 @@ int format_decode(const char *fmt, struct printf_spec *spec)
* %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

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