[PATCH 8/9] vsprintf: add %ps format specifier for symbols without offset

[Ahmad Fatoum]

%pS always prints an offset, which can look confusing outside of debug
output. Add a %ps variant like Linux also has.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 commands/kallsyms.c |  2 +-
 common/kallsyms.c   |  6 +++++-
 include/kallsyms.h  |  4 +++-
 lib/vsprintf.c      | 14 ++++++++++----
 4 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/commands/kallsyms.c b/commands/kallsyms.c
index 163cd99c1079..121d245500f9 100644
--- a/commands/kallsyms.c
+++ b/commands/kallsyms.c
@@ -22,7 +22,7 @@ static int do_kallsyms(int argc, char *argv[])
 	if (kstrtoul(argv[1], 16, &addr) == 0) {
 		char sym[KSYM_SYMBOL_LEN];
 
-		sprint_symbol(sym, addr);
+		sprint_symbol(sym, addr, true);
 
 		printf("%s\n", sym);
 		return 0;
diff --git a/common/kallsyms.c b/common/kallsyms.c
index 3c5904f8a833..61eae2794537 100644
--- a/common/kallsyms.c
+++ b/common/kallsyms.c
@@ -189,7 +189,7 @@ const char *kallsyms_lookup(unsigned long addr,
 }
 
 /* Look up a kernel symbol and return it in a text buffer. */
-int sprint_symbol(char *buffer, unsigned long address)
+int sprint_symbol(char *buffer, unsigned long address, bool with_offset)
 {
 	char *modname;
 	const char *name;
@@ -205,12 +205,16 @@ int sprint_symbol(char *buffer, unsigned long address)
 	len = strlen(buffer);
 	buffer += len;
 
+	if (!with_offset)
+		goto out;
+
 	if (modname)
 		len += sprintf(buffer, "+%#lx/%#lx [%s]",
 						offset, size, modname);
 	else
 		len += sprintf(buffer, "+%#lx/%#lx", offset, size);
 
+out:
 	return len;
 }
 EXPORT_SYMBOL_GPL(sprint_symbol);
diff --git a/include/kallsyms.h b/include/kallsyms.h
index f61efc9e0c42..c93287302bde 100644
--- a/include/kallsyms.h
+++ b/include/kallsyms.h
@@ -2,6 +2,8 @@
 #ifndef __KALLSYMS_H
 #define __KALLSYMS_H
 
+#include <linux/types.h>
+
 #define KSYM_NAME_LEN 128
 #define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
 		2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1)
@@ -12,6 +14,6 @@ const char *kallsyms_lookup(unsigned long addr,
 			    char **modname, char *namebuf);
 
 /* Look up a kernel symbol and return it in a text buffer. */
-int sprint_symbol(char *buffer, unsigned long address);
+int sprint_symbol(char *buffer, unsigned long address, bool with_offset);
 
 #endif /* __KALLSYMS_H */
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 32429dd76c23..ba87f6c210d2 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -254,12 +254,12 @@ static char *raw_pointer(char *buf, const char *end, const void *ptr, int field_
 
 #if IN_PROPER
 static char *symbol_string(char *buf, const char *end, const void *ptr, int field_width,
-			   int precision, int flags)
+			   int precision, int flags, bool with_offset)
 {
 	unsigned long value = (unsigned long) ptr;
 #ifdef CONFIG_KALLSYMS
 	char sym[KSYM_SYMBOL_LEN];
-	sprint_symbol(sym, value);
+	sprint_symbol(sym, value, with_offset);
 	return string(buf, end, sym, field_width, precision, flags);
 #else
 	field_width = 2*sizeof(void *);
@@ -484,7 +484,8 @@ char *device_node_string(char *buf, const char *end, const struct device_node *n
  *
  * Right now we handle following Linux-compatible format specifiers:
  *
- * - 'S' For symbolic direct pointers
+ * - 'S' For symbolic direct pointers (or function descriptors) with offset
+ * - 's' For symbolic direct pointers (or function descriptors) without offset
  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
  *       Options for %pU are:
@@ -523,9 +524,14 @@ char *device_node_string(char *buf, const char *end, const struct device_node *n
 static char *pointer(const char *fmt, char *buf, const char *end, const void *ptr,
 		     int field_width, int precision, int flags)
 {
+	bool with_offset = false;
+
 	switch (*fmt) {
 	case 'S':
-		return symbol_string(buf, end, ptr, field_width, precision, flags);
+		with_offset = true;
+		fallthrough;
+	case 's':
+		return symbol_string(buf, end, ptr, field_width, precision, flags, with_offset);
 	case 'U':
 		if (IS_ENABLED(CONFIG_PRINTF_UUID))
 			return uuid_string(buf, end, ptr, field_width, precision, flags, fmt);
-- 
2.39.5