[PATCH v2] linux: fix ntp_gettime abi break

[PATCH v2] linux: fix ntp_gettime abi break

[Kacper Piwiński]

[-- Attachment #1: Type: text/plain, Size: 1 bytes --]



[-- Attachment #2: v2-0001-linux-fix-ntp_gettime-abi-break.patch --]
[-- Type: text/x-patch, Size: 1533 bytes --]

From 57cfc759e3982ad591cf4d8c5f3392daf3799b3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Piwi=C5=84ski?= <vfjpl1@gmail.com>
Date: Wed, 8 Mar 2023 10:14:16 +0100
Subject: [PATCH v2] linux: fix ntp_gettime abi break

Resolves #30156
---
 sysdeps/unix/sysv/linux/ntp_gettime.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git sysdeps/unix/sysv/linux/ntp_gettime.c sysdeps/unix/sysv/linux/ntp_gettime.c
index 4879573530..af1ed920d3 100644
--- sysdeps/unix/sysv/linux/ntp_gettime.c
+++ sysdeps/unix/sysv/linux/ntp_gettime.c
@@ -26,6 +26,11 @@
 # define modes mode
 #endif
 
+/* glibc 2.12 added the 'tai' field to follow along the kernel, but it did
+   not add a compatibility symbol, instead it added __ntp_gettimex.  However
+   ntptimeval was still used in both cases, so to keep compatibility it
+   can not set all the new field.  */
+
 /* clock_adjtime64 with CLOCK_REALTIME does not trigger EINVAL,
    ENODEV, or EOPNOTSUPP.  It might still trigger EPERM.  */
 
@@ -40,7 +45,7 @@ __ntp_gettime64 (struct __ntptimeval64 *ntv)
   ntv->time = tntx.time;
   ntv->maxerror = tntx.maxerror;
   ntv->esterror = tntx.esterror;
-  ntv->tai = tntx.tai;
+
   return result;
 }
 
@@ -54,7 +59,9 @@ __ntp_gettime (struct ntptimeval *ntv)
   int result;
 
   result = __ntp_gettime64 (&ntv64);
-  *ntv = valid_ntptimeval64_to_ntptimeval (ntv64);
+  ntv->time = valid_timeval64_to_timeval (ntv64.time);
+  ntv->maxerror = ntv64.maxerror;
+  ntv->esterror = ntv64.esterror;
 
   return result;
 }
-- 
2.34.1

Re: [PATCH v2] linux: fix ntp_gettime abi break

[Florian Weimer]

* Kacper Piwiński via Libc-alpha:

> From 57cfc759e3982ad591cf4d8c5f3392daf3799b3f Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Kacper=20Piwi=C5=84ski?= <vfjpl1@gmail.com>
> Date: Wed, 8 Mar 2023 10:14:16 +0100
> Subject: [PATCH v2] linux: fix ntp_gettime abi break
>
> Resolves #30156

Could you please reference the commit(s) which introduced the ABI change
in the commit message?

Thanks,
Florian

Re: [PATCH v2] linux: fix ntp_gettime abi break

[Adhemerval Zanella Netto]

On 08/03/23 07:53, Florian Weimer via Libc-alpha wrote:
> * Kacper Piwiński via Libc-alpha:
> 
>> From 57cfc759e3982ad591cf4d8c5f3392daf3799b3f Mon Sep 17 00:00:00 2001
>> From: =?UTF-8?q?Kacper=20Piwi=C5=84ski?= <vfjpl1@gmail.com>
>> Date: Wed, 8 Mar 2023 10:14:16 +0100
>> Subject: [PATCH v2] linux: fix ntp_gettime abi break
>>
>> Resolves #30156
> 
> Could you please reference the commit(s) which introduced the ABI change
> in the commit message?

You can use your initial commit message:

--
Between versions v2.11 and v2.12 struct ntptimeval got new fields.
That wasn't a problem because new function ntp_gettimex was created
(and made default) to support new struct.  Old ntp_gettime was not
using new fields so it was safe to call with old struct
definition.  Then commits 5613afe9e3dff and b6ad64b907a (added for
64 bit time_t support), ntp_gettime start setting new fields.

Sets fields manually to maintain compatibility with v2.11 struct 
definition.
--

Re: [PATCH v2] linux: fix ntp_gettime abi break

[Kacper Piwiński]

[-- Attachment #1: Type: text/plain, Size: 1 bytes --]



[-- Attachment #2: v3-0001-linux-fix-ntp_gettime-abi-break.patch --]
[-- Type: text/x-patch, Size: 1653 bytes --]

From c9130bbacfe66c1fe5f1ad7a40293523075b1c91 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Piwi=C5=84ski?= <vfjpl1@gmail.com>
Date: Thu, 9 Mar 2023 11:38:59 +0100
Subject: [PATCH v3] linux: fix ntp_gettime abi break

introduced in:
commit 5613afe9e3dff54b10e4850804cd574e8c420e3d
commit b6ad64b907ab0066902215cf28eadc1e97307e84

Resolves #30156
---
 sysdeps/unix/sysv/linux/ntp_gettime.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/ntp_gettime.c b/sysdeps/unix/sysv/linux/ntp_gettime.c
index 4879573530..af1ed920d3 100644
--- a/sysdeps/unix/sysv/linux/ntp_gettime.c
+++ b/sysdeps/unix/sysv/linux/ntp_gettime.c
@@ -26,6 +26,11 @@
 # define modes mode
 #endif
 
+/* glibc 2.12 added the 'tai' field to follow along the kernel, but it did
+   not add a compatibility symbol, instead it added __ntp_gettimex.  However
+   ntptimeval was still used in both cases, so to keep compatibility it
+   can not set all the new field.  */
+
 /* clock_adjtime64 with CLOCK_REALTIME does not trigger EINVAL,
    ENODEV, or EOPNOTSUPP.  It might still trigger EPERM.  */
 
@@ -40,7 +45,7 @@ __ntp_gettime64 (struct __ntptimeval64 *ntv)
   ntv->time = tntx.time;
   ntv->maxerror = tntx.maxerror;
   ntv->esterror = tntx.esterror;
-  ntv->tai = tntx.tai;
+
   return result;
 }
 
@@ -54,7 +59,9 @@ __ntp_gettime (struct ntptimeval *ntv)
   int result;
 
   result = __ntp_gettime64 (&ntv64);
-  *ntv = valid_ntptimeval64_to_ntptimeval (ntv64);
+  ntv->time = valid_timeval64_to_timeval (ntv64.time);
+  ntv->maxerror = ntv64.maxerror;
+  ntv->esterror = ntv64.esterror;
 
   return result;
 }
-- 
2.34.1