Re: [PATCH v2] kunit: fix failure to build without printk

On Thu, Aug 29, 2019 at 09:44:58PM -0700, Joe Perches wrote:

On Thu, 2019-08-29 at 11:01 -0600, shuah wrote:

...

On 8/28/19 3:49 AM, Sergey Senozhatsky wrote:

...

On (08/28/19 02:31), Brendan Higgins wrote: [..]

...

Previously KUnit assumed that printk would always be present, which is not a valid assumption to make. Fix that by removing call to vprintk_emit, and calling printk directly.

Reported-by: Randy Dunlap rdunlap@infradead.org Link: https://lore.kernel.org/linux-kselftest/0352fae9-564f-4a97-715a-fabe016259df... Cc: Stephen Rothwell sfr@canb.auug.org.au Cc: Sergey Senozhatsky sergey.senozhatsky.work@gmail.com Signed-off-by: Brendan Higgins brendanhiggins@google.com

[..]

...

-static void kunit_vprintk(const struct kunit *test,

• 	  const char *level,
  

• 	  struct va_format *vaf)
  

-{

• kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf);

-}

This patch looks good to me. I like the removal of recursive vsprintf() (%pV).

-ss

Hi Sergey,

What are the guidelines for using printk(). I recall some discussion about not using printk(). I am seeing the following from checkpatch script:

WARNING: Prefer [subsystem eg: netdev]_level([subsystem]dev, ... then dev_level(dev, ... then pr_level(... to printk(KERN_LEVEL ... #105: FILE: include/kunit/test.h:343:

• printk(KERN_LEVEL "\t# %s: " fmt, (test)->name, ##__VA_ARGS__)

Is there supposed to be pr_level() - I can find dev_level()

cc'ing Joe Perches for his feedback on this message recommending pr_level() which isn't in 5.3.

I don't care for pr_level or KERN_LEVEL in a printk.

I don't think I follow, how does your version fix this?

I think this is somewhat overly complicated.

I think I'd write it like:

include/kunit/test.h | 11 ++++----- kunit/test.c | 69 ++++++++++++++++------------------------------------ 2 files changed, 26 insertions(+), 54 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h index 8b7eb03d4971..aa4abf0a22a5 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -339,9 +339,8 @@ static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp) void kunit_cleanup(struct kunit *test); -void __printf(3, 4) kunit_printk(const char *level,

• 		 const struct kunit *test,
  

• 		 const char *fmt, ...);
  

+__printf(2, 3) +void kunit_printk(const struct kunit *test, const char *fmt, ...); /**

• kunit_info() - Prints an INFO level message associated with @test.

@@ -353,7 +352,7 @@ void __printf(3, 4) kunit_printk(const char *level,

• Takes a variable number of format parameters just like printk().

*/ #define kunit_info(test, fmt, ...) \

• kunit_printk(KERN_INFO, test, fmt, ##__VA_ARGS__)

• kunit_printk(test, KERN_INFO fmt, ##__VA_ARGS__)

/**

• kunit_warn() - Prints a WARN level message associated with @test.

@@ -364,7 +363,7 @@ void __printf(3, 4) kunit_printk(const char *level,

• Prints a warning level message.

*/ #define kunit_warn(test, fmt, ...) \

• kunit_printk(KERN_WARNING, test, fmt, ##__VA_ARGS__)

• kunit_printk(test, KERN_WARNING fmt, ##__VA_ARGS__)

/**

• kunit_err() - Prints an ERROR level message associated with @test.

@@ -375,7 +374,7 @@ void __printf(3, 4) kunit_printk(const char *level,

• Prints an error level message.

*/ #define kunit_err(test, fmt, ...) \

• kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__)

• kunit_printk(test, KERN_ERR fmt, ##__VA_ARGS__)

/**

• KUNIT_SUCCEED() - A no-op expectation. Only exists for code clarity.

diff --git a/kunit/test.c b/kunit/test.c index b2ca9b94c353..ddb9bffb5a5d 100644 --- a/kunit/test.c +++ b/kunit/test.c @@ -16,40 +16,6 @@ static void kunit_set_failure(struct kunit *test) WRITE_ONCE(test->success, false); } -static int kunit_vprintk_emit(int level, const char *fmt, va_list args) -{

• return vprintk_emit(0, level, NULL, 0, fmt, args);

-}

-static int kunit_printk_emit(int level, const char *fmt, ...) -{

• va_list args;
• int ret;
• va_start(args, fmt);
• ret = kunit_vprintk_emit(level, fmt, args);
• va_end(args);
• return ret;

-}

-static void kunit_vprintk(const struct kunit *test,

• 	  const char *level,
  

• 	  struct va_format *vaf)
  

-{

• kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf);

-}

-static void kunit_print_tap_version(void) -{

• static bool kunit_has_printed_tap_version;
• if (!kunit_has_printed_tap_version) {

• kunit_printk_emit(LOGLEVEL_INFO, "TAP version 14\n");
  

• kunit_has_printed_tap_version = true;
  

• }

-}

static size_t kunit_test_cases_len(struct kunit_case *test_cases) { struct kunit_case *test_case; @@ -63,11 +29,9 @@ static size_t kunit_test_cases_len(struct kunit_case *test_cases) static void kunit_print_subtest_start(struct kunit_suite *suite) {

• kunit_print_tap_version();
• kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", suite->name);
• kunit_printk_emit(LOGLEVEL_INFO,

• 	  "\t1..%zd\n",
  

• 	  kunit_test_cases_len(suite->test_cases));
  

• pr_info_once("TAP version 14\n");
• pr_info("\t# Subtest: %s\n", suite->name);
• pr_info("\t1..%zd\n", kunit_test_cases_len(suite->test_cases));

} static void kunit_print_ok_not_ok(bool should_indent, @@ -87,9 +51,8 @@ static void kunit_print_ok_not_ok(bool should_indent, else ok_not_ok = "not ok";

• kunit_printk_emit(LOGLEVEL_INFO,

• 	  "%s%s %zd - %s\n",
  

• 	  indent, ok_not_ok, test_number, description);
  

• pr_info("%s%s %zd - %s\n",

• indent, ok_not_ok, test_number, description);
  

} static bool kunit_suite_has_succeeded(struct kunit_suite *suite) @@ -133,11 +96,11 @@ static void kunit_print_string_stream(struct kunit *test, kunit_err(test, "Could not allocate buffer, dumping stream:\n"); list_for_each_entry(fragment, &stream->fragments, node) {

• 	kunit_err(test, fragment->fragment);
  

• 	kunit_err(test, "%s", fragment->fragment);
  

  } kunit_err(test, "\n"); } else {

• kunit_err(test, buf);
  

• kunit_err(test, "%s", buf);
  

  kunit_kfree(test, buf); }

} @@ -505,19 +468,29 @@ void kunit_cleanup(struct kunit *test) } } -void kunit_printk(const char *level,

•   const struct kunit *test,
  

•   const char *fmt, ...)
  

+void kunit_printk(const struct kunit *test, const char *fmt, ...) {

• char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0"; struct va_format vaf; va_list args;
• int kern_level;

va_start(args, fmt);

• while ((kern_level = printk_get_level(fmt)) != 0) {

• size_t size = printk_skip_level(fmt) - fmt;
  

• if (kern_level >= '0' && kern_level <= '7') {
  

• 	memcpy(lvl, fmt,  size);
  

• 	lvl[size] = '\0';
  

• }
  

• fmt += size;
  

• }
• vaf.fmt = fmt; vaf.va = &args;

• kunit_vprintk(test, level, &vaf);

• printk("%s\t# %s %pV\n", lvl, test->name, &vaf);

va_end(args); }

How is this simpler?

If we are okay with dynamically adding the KERN_<LEVEL> and %pV (and I don't think that Sergey is), then wouldn't it be easier to pass in the kernel level as a separate parameter and then strip off all printk headers like this:

void kunit_printk(const char *level, const struct kunit *test, const char *fmt, ...) { struct va_format vaf; va_list args;

va_start(args, fmt);

+ fmt = printk_skip_headers(fmt); + vaf.fmt = fmt; vaf.va = &args;

- kunit_vprintk(test, level, &vaf); + printk("%s\t# %s %pV\n", level, test->name, &vaf);

va_end(args); }

Then the kunit_printk function is much simpler, and I don't think my header file has to change at all.

I don't know. I am clearly not an expert on this topic, but I don't see the merit of the while loop you added above or dropping the level param.