| Message ID | 20170717135948.19748-1-arkadiusz.hiler@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jul 17, 2017 at 04:59:48PM +0300, Arkadiusz Hiler wrote: > The documentation was lying. The igt_crc_to_string() is threadsafe and > does not return a pointer to an internal buffer. > > Actually the caller is responsible for the memory that is allocated (and > they are for all the current cases), so let's put that in the doc too. > > While I was at it I got rid of strdup() in favor of an early allocation. > > Cc: Martin Peres <martin.peres@intel.com> > Cc: Liviu Dudau <liviu.dudau@arm.com> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com> > Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com> > --- > lib/igt_debugfs.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c > index 80f25c6..5e4d72c 100644 > --- a/lib/igt_debugfs.c > +++ b/lib/igt_debugfs.c > @@ -304,21 +304,20 @@ void igt_assert_crc_equal(const igt_crc_t *a, const igt_crc_t *b) > * igt_crc_to_string: > * @crc: pipe CRC value to print > * > - * This formats @crc into a string buffer which is owned by igt_crc_to_string(). > - * The next call will override the buffer again, which makes this multithreading > - * unsafe. > + * This formats @crc into a string. Function allocates memory - the caller is > + * in charge of freeing it. > * > * This should only ever be used for diagnostic debug output. > */ > char *igt_crc_to_string(igt_crc_t *crc) > { > int i; > - char buf[128] = { 0 }; > + char *buf = calloc(128, sizeof(char)); > > for (i = 0; i < crc->n_words; i++) > sprintf(buf + strlen(buf), "%08x ", crc->crc[i]); > > - return strdup(buf); > + return buf; > } > > #define MAX_CRC_ENTRIES 10 > -- > 2.9.4 >
clenup -> cleanup On 17/07/17 18:05, Liviu Dudau wrote: > On Mon, Jul 17, 2017 at 04:59:48PM +0300, Arkadiusz Hiler wrote: >> The documentation was lying. The igt_crc_to_string() is threadsafe and >> does not return a pointer to an internal buffer. >> >> Actually the caller is responsible for the memory that is allocated (and >> they are for all the current cases), so let's put that in the doc too. >> >> While I was at it I got rid of strdup() in favor of an early allocation. >> >> Cc: Martin Peres <martin.peres@intel.com> >> Cc: Liviu Dudau <liviu.dudau@arm.com> > > Reviewed-by: Liviu Dudau <liviu.dudau@arm.com> > >> Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com> >> --- >> lib/igt_debugfs.c | 9 ++++----- >> 1 file changed, 4 insertions(+), 5 deletions(-) >> >> diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c >> index 80f25c6..5e4d72c 100644 >> --- a/lib/igt_debugfs.c >> +++ b/lib/igt_debugfs.c >> @@ -304,21 +304,20 @@ void igt_assert_crc_equal(const igt_crc_t *a, const igt_crc_t *b) >> * igt_crc_to_string: >> * @crc: pipe CRC value to print >> * >> - * This formats @crc into a string buffer which is owned by igt_crc_to_string(). >> - * The next call will override the buffer again, which makes this multithreading >> - * unsafe. >> + * This formats @crc into a string. Function allocates memory - the caller is >> + * in charge of freeing it. These sentences are a little strange from a grammatical point of view. How about: This function allocates a string and formats @crc into it. The caller is responsible for freeing the string. >> * >> * This should only ever be used for diagnostic debug output. >> */ >> char *igt_crc_to_string(igt_crc_t *crc) >> { >> int i; >> - char buf[128] = { 0 }; >> + char *buf = calloc(128, sizeof(char)); To mimic the previous code's behaviour, please add the following: if (!buf) return NULL; >> >> for (i = 0; i < crc->n_words; i++) >> sprintf(buf + strlen(buf), "%08x ", crc->crc[i]); >> >> - return strdup(buf); >> + return buf; >> } >> >> #define MAX_CRC_ENTRIES 10 >> -- >> 2.9.4 >> > With at least the title and code fixed, this is: Reviewed-by: Martin Peres <martin.peres@linux.intel.com> Thanks for doing this :) Martin --------------------------------------------------------------------- Intel Finland Oy Registered Address: PL 281, 00181 Helsinki Business Identity Code: 0357606 - 4 Domiciled in Helsinki This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.
diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c index 80f25c6..5e4d72c 100644 --- a/lib/igt_debugfs.c +++ b/lib/igt_debugfs.c @@ -304,21 +304,20 @@ void igt_assert_crc_equal(const igt_crc_t *a, const igt_crc_t *b) * igt_crc_to_string: * @crc: pipe CRC value to print * - * This formats @crc into a string buffer which is owned by igt_crc_to_string(). - * The next call will override the buffer again, which makes this multithreading - * unsafe. + * This formats @crc into a string. Function allocates memory - the caller is + * in charge of freeing it. * * This should only ever be used for diagnostic debug output. */ char *igt_crc_to_string(igt_crc_t *crc) { int i; - char buf[128] = { 0 }; + char *buf = calloc(128, sizeof(char)); for (i = 0; i < crc->n_words; i++) sprintf(buf + strlen(buf), "%08x ", crc->crc[i]); - return strdup(buf); + return buf; } #define MAX_CRC_ENTRIES 10
The documentation was lying. The igt_crc_to_string() is threadsafe and does not return a pointer to an internal buffer. Actually the caller is responsible for the memory that is allocated (and they are for all the current cases), so let's put that in the doc too. While I was at it I got rid of strdup() in favor of an early allocation. Cc: Martin Peres <martin.peres@intel.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com> --- lib/igt_debugfs.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)