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Commit b0d33c2b authored by Joe Perches's avatar Joe Perches Committed by Jiri Kosina
Browse files

vsprintf: Add extension %pSR - print_symbol replacement 



print_symbol takes a long and converts it to a function
name and offset.  %pS does something similar, but doesn't
translate the address via __builtin_extract_return_addr.
%pSR does the translation.

This will enable replacing multiple calls like
	printk(...);
	printk_symbol(addr);
	printk("\n");
with a single non-interleavable in dmesg
	printk("... %pSR\n", (void *)addr);

Update documentation too.

Signed-off-by: default avatarJoe Perches <joe@perches.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 071361d3

Documentation/printk-formats.txt

+2 −0
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ Symbols/Function Pointers: 
	%pF	versatile_init+0x0/0x110

	%pf	versatile_init

	%pS	versatile_init+0x0/0x110

	%pSR	versatile_init+0x9/0x110

		(with __builtin_extract_return_addr() translation)

	%ps	versatile_init

	%pB	prev_fn_of_versatile_init+0x88/0x88

lib/vsprintf.c

+13 −5
Original line number Diff line number Diff line
@@ -534,14 +534,21 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec) 


static noinline_for_stack

char *symbol_string(char *buf, char *end, void *ptr,

		    struct printf_spec spec, char ext)

		    struct printf_spec spec, const char *fmt)

{

	unsigned long value = (unsigned long) ptr;

	unsigned long value;

#ifdef CONFIG_KALLSYMS

	char sym[KSYM_SYMBOL_LEN];

	if (ext == 'B')

#endif



	if (fmt[1] == 'R')

		ptr = __builtin_extract_return_addr(ptr);

	value = (unsigned long)ptr;



#ifdef CONFIG_KALLSYMS

	if (*fmt == 'B')

		sprint_backtrace(sym, value);

	else if (ext != 'f' && ext != 's')

	else if (*fmt != 'f' && *fmt != 's')

		sprint_symbol(sym, value);

	else

		sprint_symbol_no_offset(sym, value);
@@ -987,6 +994,7 @@ int kptr_restrict __read_mostly; 
 * - 'f' For simple symbolic function names without offset

 * - 'S' For symbolic direct pointers with offset

 * - 's' For symbolic direct pointers without offset

 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation

 * - '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]
@@ -1060,7 +1068,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, 
	case 'S':

	case 's':

	case 'B':

		return symbol_string(buf, end, ptr, spec, *fmt);

		return symbol_string(buf, end, ptr, spec, fmt);

	case 'R':

	case 'r':

		return resource_string(buf, end, ptr, spec, fmt);