linux/lib/test_printf.c
Vlastimil Babka edf14cdbf9 mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs.  To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names.  So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g.  sysfs export.

To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv).  Existing users of
dump_flag_names() are converted and simplified.

It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.

[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00

513 lines
12 KiB
C

/*
* Test cases for printf facility.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/bitmap.h>
#include <linux/dcache.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#define BUF_SIZE 256
#define PAD_SIZE 16
#define FILL_CHAR '$'
#define PTR1 ((void*)0x01234567)
#define PTR2 ((void*)(long)(int)0xfedcba98)
#if BITS_PER_LONG == 64
#define PTR1_ZEROES "000000000"
#define PTR1_SPACES " "
#define PTR1_STR "1234567"
#define PTR2_STR "fffffffffedcba98"
#define PTR_WIDTH 16
#else
#define PTR1_ZEROES "0"
#define PTR1_SPACES " "
#define PTR1_STR "1234567"
#define PTR2_STR "fedcba98"
#define PTR_WIDTH 8
#endif
#define PTR_WIDTH_STR stringify(PTR_WIDTH)
static unsigned total_tests __initdata;
static unsigned failed_tests __initdata;
static char *test_buffer __initdata;
static char *alloced_buffer __initdata;
static int __printf(4, 0) __init
do_test(int bufsize, const char *expect, int elen,
const char *fmt, va_list ap)
{
va_list aq;
int ret, written;
total_tests++;
memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
va_copy(aq, ap);
ret = vsnprintf(test_buffer, bufsize, fmt, aq);
va_end(aq);
if (ret != elen) {
pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
bufsize, fmt, ret, elen);
return 1;
}
if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
return 1;
}
if (!bufsize) {
if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
fmt);
return 1;
}
return 0;
}
written = min(bufsize-1, elen);
if (test_buffer[written]) {
pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
bufsize, fmt);
return 1;
}
if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
bufsize, fmt);
return 1;
}
if (memcmp(test_buffer, expect, written)) {
pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
bufsize, fmt, test_buffer, written, expect);
return 1;
}
return 0;
}
static void __printf(3, 4) __init
__test(const char *expect, int elen, const char *fmt, ...)
{
va_list ap;
int rand;
char *p;
if (elen >= BUF_SIZE) {
pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
elen, fmt);
failed_tests++;
return;
}
va_start(ap, fmt);
/*
* Every fmt+args is subjected to four tests: Three where we
* tell vsnprintf varying buffer sizes (plenty, not quite
* enough and 0), and then we also test that kvasprintf would
* be able to print it as expected.
*/
failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
rand = 1 + prandom_u32_max(elen+1);
/* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
failed_tests += do_test(rand, expect, elen, fmt, ap);
failed_tests += do_test(0, expect, elen, fmt, ap);
p = kvasprintf(GFP_KERNEL, fmt, ap);
if (p) {
total_tests++;
if (memcmp(p, expect, elen+1)) {
pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
fmt, p, expect);
failed_tests++;
}
kfree(p);
}
va_end(ap);
}
#define test(expect, fmt, ...) \
__test(expect, strlen(expect), fmt, ##__VA_ARGS__)
static void __init
test_basic(void)
{
/* Work around annoying "warning: zero-length gnu_printf format string". */
char nul = '\0';
test("", &nul);
test("100%", "100%%");
test("xxx%yyy", "xxx%cyyy", '%');
__test("xxx\0yyy", 7, "xxx%cyyy", '\0');
}
static void __init
test_number(void)
{
test("0x1234abcd ", "%#-12x", 0x1234abcd);
test(" 0x1234abcd", "%#12x", 0x1234abcd);
test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
/*
* POSIX/C99: »The result of converting zero with an explicit
* precision of zero shall be no characters.« Hence the output
* from the below test should really be "00|0||| ". However,
* the kernel's printf also produces a single 0 in that
* case. This test case simply documents the current
* behaviour.
*/
test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
#ifndef __CHAR_UNSIGNED__
{
/*
* Passing a 'char' to a %02x specifier doesn't do
* what was presumably the intention when char is
* signed and the value is negative. One must either &
* with 0xff or cast to u8.
*/
char val = -16;
test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
}
#endif
}
static void __init
test_string(void)
{
test("", "%s%.0s", "", "123");
test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
test("1 | 2|3 | 4|5 ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
test("1234 ", "%-10.4s", "123456");
test(" 1234", "%10.4s", "123456");
/*
* POSIX and C99 say that a negative precision (which is only
* possible to pass via a * argument) should be treated as if
* the precision wasn't present, and that if the precision is
* omitted (as in %.s), the precision should be taken to be
* 0. However, the kernel's printf behave exactly opposite,
* treating a negative precision as 0 and treating an omitted
* precision specifier as if no precision was given.
*
* These test cases document the current behaviour; should
* anyone ever feel the need to follow the standards more
* closely, this can be revisited.
*/
test(" ", "%4.*s", -5, "123456");
test("123456", "%.s", "123456");
test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
test("a | | ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
}
static void __init
plain(void)
{
test(PTR1_ZEROES PTR1_STR " " PTR2_STR, "%p %p", PTR1, PTR2);
/*
* The field width is overloaded for some %p extensions to
* pass another piece of information. For plain pointers, the
* behaviour is slightly odd: One cannot pass either the 0
* flag nor a precision to %p without gcc complaining, and if
* one explicitly gives a field width, the number is no longer
* zero-padded.
*/
test("|" PTR1_STR PTR1_SPACES " | " PTR1_SPACES PTR1_STR "|",
"|%-*p|%*p|", PTR_WIDTH+2, PTR1, PTR_WIDTH+2, PTR1);
test("|" PTR2_STR " | " PTR2_STR "|",
"|%-*p|%*p|", PTR_WIDTH+2, PTR2, PTR_WIDTH+2, PTR2);
/*
* Unrecognized %p extensions are treated as plain %p, but the
* alphanumeric suffix is ignored (that is, does not occur in
* the output.)
*/
test("|"PTR1_ZEROES PTR1_STR"|", "|%p0y|", PTR1);
test("|"PTR2_STR"|", "|%p0y|", PTR2);
}
static void __init
symbol_ptr(void)
{
}
static void __init
kernel_ptr(void)
{
}
static void __init
struct_resource(void)
{
}
static void __init
addr(void)
{
}
static void __init
escaped_str(void)
{
}
static void __init
hex_string(void)
{
const char buf[3] = {0xc0, 0xff, 0xee};
test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
"%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
"%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
}
static void __init
mac(void)
{
const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
test("2d:48:d6:fc:7a:05", "%pM", addr);
test("05:7a:fc:d6:48:2d", "%pMR", addr);
test("2d-48-d6-fc-7a-05", "%pMF", addr);
test("2d48d6fc7a05", "%pm", addr);
test("057afcd6482d", "%pmR", addr);
}
static void __init
ip4(void)
{
struct sockaddr_in sa;
sa.sin_family = AF_INET;
sa.sin_port = cpu_to_be16(12345);
sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
}
static void __init
ip6(void)
{
}
static void __init
ip(void)
{
ip4();
ip6();
}
static void __init
uuid(void)
{
const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
}
static struct dentry test_dentry[4] __initdata = {
{ .d_parent = &test_dentry[0],
.d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
.d_iname = "foo" },
{ .d_parent = &test_dentry[0],
.d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
.d_iname = "bravo" },
{ .d_parent = &test_dentry[1],
.d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
.d_iname = "alfa" },
{ .d_parent = &test_dentry[2],
.d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
.d_iname = "romeo" },
};
static void __init
dentry(void)
{
test("foo", "%pd", &test_dentry[0]);
test("foo", "%pd2", &test_dentry[0]);
test("romeo", "%pd", &test_dentry[3]);
test("alfa/romeo", "%pd2", &test_dentry[3]);
test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
test("/bravo/alfa", "%pd4", &test_dentry[2]);
test("bravo/alfa |bravo/alfa ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
test(" bravo/alfa| bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
}
static void __init
struct_va_format(void)
{
}
static void __init
struct_clk(void)
{
}
static void __init
large_bitmap(void)
{
const int nbits = 1 << 16;
unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
if (!bits)
return;
bitmap_set(bits, 1, 20);
bitmap_set(bits, 60000, 15);
test("1-20,60000-60014", "%*pbl", nbits, bits);
kfree(bits);
}
static void __init
bitmap(void)
{
DECLARE_BITMAP(bits, 20);
const int primes[] = {2,3,5,7,11,13,17,19};
int i;
bitmap_zero(bits, 20);
test("00000|00000", "%20pb|%*pb", bits, 20, bits);
test("|", "%20pbl|%*pbl", bits, 20, bits);
for (i = 0; i < ARRAY_SIZE(primes); ++i)
set_bit(primes[i], bits);
test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
bitmap_fill(bits, 20);
test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
large_bitmap();
}
static void __init
netdev_features(void)
{
}
static void __init
flags(void)
{
unsigned long flags;
gfp_t gfp;
char *cmp_buffer;
flags = 0;
test("", "%pGp", &flags);
/* Page flags should filter the zone id */
flags = 1UL << NR_PAGEFLAGS;
test("", "%pGp", &flags);
flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
| 1UL << PG_active | 1UL << PG_swapbacked;
test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
| VM_DENYWRITE;
test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
gfp = GFP_TRANSHUGE;
test("GFP_TRANSHUGE", "%pGg", &gfp);
gfp = GFP_ATOMIC|__GFP_DMA;
test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
gfp = __GFP_ATOMIC;
test("__GFP_ATOMIC", "%pGg", &gfp);
cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
if (!cmp_buffer)
return;
/* Any flags not translated by the table should remain numeric */
gfp = ~__GFP_BITS_MASK;
snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
test(cmp_buffer, "%pGg", &gfp);
snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
(unsigned long) gfp);
gfp |= __GFP_ATOMIC;
test(cmp_buffer, "%pGg", &gfp);
kfree(cmp_buffer);
}
static void __init
test_pointer(void)
{
plain();
symbol_ptr();
kernel_ptr();
struct_resource();
addr();
escaped_str();
hex_string();
mac();
ip();
uuid();
dentry();
struct_va_format();
struct_clk();
bitmap();
netdev_features();
flags();
}
static int __init
test_printf_init(void)
{
alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
if (!alloced_buffer)
return -ENOMEM;
test_buffer = alloced_buffer + PAD_SIZE;
test_basic();
test_number();
test_string();
test_pointer();
kfree(alloced_buffer);
if (failed_tests == 0)
pr_info("all %u tests passed\n", total_tests);
else
pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
return failed_tests ? -EINVAL : 0;
}
module_init(test_printf_init);
MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
MODULE_LICENSE("GPL");