[dpdk-dev] [PATCH] eal: fix broken rte strerror

[dpdk-dev] [PATCH] eal: fix broken rte strerror

[Jerin Jacob]

errno_autotest testcase were failed since
commit 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")
RTE>>errno_autotest
rte_strerror: 'Unknown error 11',
strerror: 'Resource temporarily unavailable'
Test Failed

There are two different version of strerror_t() based on
_GNU_SOURCE definition.

/* XSI-compliant */
int strerror_r(int errnum, char *buf, size_t buflen);

/* GNU-specific */
char *strerror_r(int errnum, char *buf, size_t buflen);

Since the GNU-specific version returns char* the exiting "if"
condition around the strerror_r fails.

Switching back to XSI-compliant version to allow

a) Portable strerror_r() usage as musl c library uses
non GNU speficic version
https://git.musl-libc.org/cgit/musl/tree/src/string/strerror_r.c

b) Based on strerror_r(3) man page, it is possible that GNU-specific
version need not use char *buf to fill error message instead it
can use the immutable static string from the library and return it.

note from strerror_r(3) man page:

The GNU-specific strerror_r() returns a pointer to a string containing
the error message.  This may be either a pointer to a string that the
function stores in buf, or a pointer to some (immutable)
static string (in which case buf is unused).

Fixes: 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
 lib/librte_eal/common/eal_common_errno.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_errno.c b/lib/librte_eal/common/eal_common_errno.c
index 56b492f5f..c63a943b3 100644
--- a/lib/librte_eal/common/eal_common_errno.c
+++ b/lib/librte_eal/common/eal_common_errno.c
@@ -2,6 +2,9 @@
  * Copyright(c) 2010-2014 Intel Corporation
  */
 
+/* Use XSI-compliant portable version of strerror_r() */
+#undef _GNU_SOURCE
+
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
-- 
2.19.1

Re: [dpdk-dev] [PATCH] eal: fix broken rte strerror

[Thomas Monjalon]

02/11/2018 09:11, Jerin Jacob:
> errno_autotest testcase were failed since
> commit 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")
> RTE>>errno_autotest
> rte_strerror: 'Unknown error 11',
> strerror: 'Resource temporarily unavailable'
> Test Failed
> 
> There are two different version of strerror_t() based on
> _GNU_SOURCE definition.
> 
> /* XSI-compliant */
> int strerror_r(int errnum, char *buf, size_t buflen);
> 
> /* GNU-specific */
> char *strerror_r(int errnum, char *buf, size_t buflen);
> 
> Since the GNU-specific version returns char* the exiting "if"
> condition around the strerror_r fails.
> 
> Switching back to XSI-compliant version to allow
> 
> a) Portable strerror_r() usage as musl c library uses
> non GNU speficic version
> https://git.musl-libc.org/cgit/musl/tree/src/string/strerror_r.c
> 
> b) Based on strerror_r(3) man page, it is possible that GNU-specific
> version need not use char *buf to fill error message instead it
> can use the immutable static string from the library and return it.
> 
> note from strerror_r(3) man page:
> 
> The GNU-specific strerror_r() returns a pointer to a string containing
> the error message.  This may be either a pointer to a string that the
> function stores in buf, or a pointer to some (immutable)
> static string (in which case buf is unused).
> 
> Fixes: 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")
> 
> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

You may be interested by this patch from Ferruh:
	https://patches.dpdk.org/patch/47622/

Re: [dpdk-dev] [PATCH] eal: fix broken rte strerror

[Ferruh Yigit]

On 11/2/2018 9:41 AM, Thomas Monjalon wrote:
> 02/11/2018 09:11, Jerin Jacob:
>> errno_autotest testcase were failed since
>> commit 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")
>> RTE>>errno_autotest
>> rte_strerror: 'Unknown error 11',
>> strerror: 'Resource temporarily unavailable'
>> Test Failed
>>
>> There are two different version of strerror_t() based on
>> _GNU_SOURCE definition.
>>
>> /* XSI-compliant */
>> int strerror_r(int errnum, char *buf, size_t buflen);
>>
>> /* GNU-specific */
>> char *strerror_r(int errnum, char *buf, size_t buflen);
>>
>> Since the GNU-specific version returns char* the exiting "if"
>> condition around the strerror_r fails.
>>
>> Switching back to XSI-compliant version to allow
>>
>> a) Portable strerror_r() usage as musl c library uses
>> non GNU speficic version
>> https://git.musl-libc.org/cgit/musl/tree/src/string/strerror_r.c
>>
>> b) Based on strerror_r(3) man page, it is possible that GNU-specific
>> version need not use char *buf to fill error message instead it
>> can use the immutable static string from the library and return it.
>>
>> note from strerror_r(3) man page:
>>
>> The GNU-specific strerror_r() returns a pointer to a string containing
>> the error message.  This may be either a pointer to a string that the
>> function stores in buf, or a pointer to some (immutable)
>> static string (in which case buf is unused).
>>
>> Fixes: 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")
>>
>> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> 
> You may be interested by this patch from Ferruh:
> 	https://patches.dpdk.org/patch/47622/

Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

Re: [dpdk-dev] [PATCH] eal: fix broken rte strerror

[Thomas Monjalon]

02/11/2018 18:20, Ferruh Yigit:
> On 11/2/2018 9:41 AM, Thomas Monjalon wrote:
> > 02/11/2018 09:11, Jerin Jacob:
> >> errno_autotest testcase were failed since
> >> commit 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")
> >> RTE>>errno_autotest
> >> rte_strerror: 'Unknown error 11',
> >> strerror: 'Resource temporarily unavailable'
> >> Test Failed
> >>
> >> There are two different version of strerror_t() based on
> >> _GNU_SOURCE definition.
> >>
> >> /* XSI-compliant */
> >> int strerror_r(int errnum, char *buf, size_t buflen);
> >>
> >> /* GNU-specific */
> >> char *strerror_r(int errnum, char *buf, size_t buflen);
> >>
> >> Since the GNU-specific version returns char* the exiting "if"
> >> condition around the strerror_r fails.
> >>
> >> Switching back to XSI-compliant version to allow
> >>
> >> a) Portable strerror_r() usage as musl c library uses
> >> non GNU speficic version
> >> https://git.musl-libc.org/cgit/musl/tree/src/string/strerror_r.c
> >>
> >> b) Based on strerror_r(3) man page, it is possible that GNU-specific
> >> version need not use char *buf to fill error message instead it
> >> can use the immutable static string from the library and return it.
> >>
> >> note from strerror_r(3) man page:
> >>
> >> The GNU-specific strerror_r() returns a pointer to a string containing
> >> the error message.  This may be either a pointer to a string that the
> >> function stores in buf, or a pointer to some (immutable)
> >> static string (in which case buf is unused).
> >>
> >> Fixes: 5d7b673d5fd6 ("mk: build with _GNU_SOURCE defined by default")
> >>
> >> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> > 
> > You may be interested by this patch from Ferruh:
> > 	https://patches.dpdk.org/patch/47622/
> 
> Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

Applied, thanks