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-rw-r--r--lib/vsprintf.c128
1 files changed, 93 insertions, 35 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 6021757a449..1dc2d1d18fa 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -22,6 +22,8 @@
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/kernel.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
#include <asm/page.h> /* for PAGE_SIZE */
#include <asm/div64.h>
@@ -482,6 +484,89 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int
return buf;
}
+static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags)
+{
+ int len, i;
+
+ if ((unsigned long)s < PAGE_SIZE)
+ s = "<NULL>";
+
+ len = strnlen(s, precision);
+
+ if (!(flags & LEFT)) {
+ while (len < field_width--) {
+ if (buf < end)
+ *buf = ' ';
+ ++buf;
+ }
+ }
+ for (i = 0; i < len; ++i) {
+ if (buf < end)
+ *buf = *s;
+ ++buf; ++s;
+ }
+ while (len < field_width--) {
+ if (buf < end)
+ *buf = ' ';
+ ++buf;
+ }
+ return buf;
+}
+
+static inline void *dereference_function_descriptor(void *ptr)
+{
+#if defined(CONFIG_IA64) || defined(CONFIG_PPC64)
+ void *p;
+ if (!probe_kernel_address(ptr, p))
+ ptr = p;
+#endif
+ return ptr;
+}
+
+static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags)
+{
+ unsigned long value = (unsigned long) ptr;
+#ifdef CONFIG_KALLSYMS
+ char sym[KSYM_SYMBOL_LEN];
+ sprint_symbol(sym, value);
+ return string(buf, end, sym, field_width, precision, flags);
+#else
+ field_width = 2*sizeof(void *);
+ flags |= SPECIAL | SMALL | ZEROPAD;
+ return number(buf, end, value, 16, field_width, precision, flags);
+#endif
+}
+
+/*
+ * Show a '%p' thing. A kernel extension is that the '%p' is followed
+ * by an extra set of alphanumeric characters that are extended format
+ * specifiers.
+ *
+ * Right now we just handle 'F' (for symbolic Function descriptor pointers)
+ * and 'S' (for Symbolic direct pointers), but this can easily be
+ * extended in the future (network address types etc).
+ *
+ * The difference between 'S' and 'F' is that on ia64 and ppc64 function
+ * pointers are really function descriptors, which contain a pointer the
+ * real address.
+ */
+static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags)
+{
+ switch (*fmt) {
+ case 'F':
+ ptr = dereference_function_descriptor(ptr);
+ /* Fallthrough */
+ case 'S':
+ return symbol_string(buf, end, ptr, field_width, precision, flags);
+ }
+ flags |= SMALL;
+ if (field_width == -1) {
+ field_width = 2*sizeof(void *);
+ flags |= ZEROPAD;
+ }
+ return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags);
+}
+
/**
* vsnprintf - Format a string and place it in a buffer
* @buf: The buffer to place the result into
@@ -502,11 +587,9 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int
*/
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
- int len;
unsigned long long num;
- int i, base;
+ int base;
char *str, *end, c;
- const char *s;
int flags; /* flags to number() */
@@ -622,43 +705,18 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
continue;
case 's':
- s = va_arg(args, char *);
- if ((unsigned long)s < PAGE_SIZE)
- s = "<NULL>";
-
- len = strnlen(s, precision);
-
- if (!(flags & LEFT)) {
- while (len < field_width--) {
- if (str < end)
- *str = ' ';
- ++str;
- }
- }
- for (i = 0; i < len; ++i) {
- if (str < end)
- *str = *s;
- ++str; ++s;
- }
- while (len < field_width--) {
- if (str < end)
- *str = ' ';
- ++str;
- }
+ str = string(str, end, va_arg(args, char *), field_width, precision, flags);
continue;
case 'p':
- flags |= SMALL;
- if (field_width == -1) {
- field_width = 2*sizeof(void *);
- flags |= ZEROPAD;
- }
- str = number(str, end,
- (unsigned long) va_arg(args, void *),
- 16, field_width, precision, flags);
+ str = pointer(fmt+1, str, end,
+ va_arg(args, void *),
+ field_width, precision, flags);
+ /* Skip all alphanumeric pointer suffixes */
+ while (isalnum(fmt[1]))
+ fmt++;
continue;
-
case 'n':
/* FIXME:
* What does C99 say about the overflow case here? */