package/glibc: add a patch to fix build issue in kernels >= 3.15 and < 5.1 on Microblaze

As explained in the patch itself, there is a bug in the handling of
__pselect32() in glibc for the Microblaze architecture. There a
special Microblaze variant that was added to support kernels older
than < 3.15, but it "hides" a generic implementation that is needed to
support kernels newer than 3.15 but older than 5.1 (which is when the
time64 support for 32-bit architectures was added, making __pselect32
no longer needed).

This bug causes a glibc build failure for kernels >= 3.15 but < 5.1,
on Microblaze.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
This commit is contained in:
Thomas Petazzoni 2021-12-26 11:45:19 +01:00 committed by Yann E. MORIN
parent 9ae792cc01
commit 17ebb6ffae

View file

@ -0,0 +1,85 @@
From af06fe63f9babb6d0179ae5d7d9245daada6bf56 Mon Sep 17 00:00:00 2001
From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Date: Sun, 26 Dec 2021 10:30:01 +0100
Subject: [PATCH] sysdeps/unix/sysv/linux/microblaze/pselect32.c: add missing
implementation when !__ASSUME_TIME64_SYSCALLS
In commit a92f4e6299fe0e3cb6f77e79de00817aece501ce ("linux: Add time64
pselect support"), a Microblaze specific implementation of
__pselect32() was added to cover the case of kernels < 3.15 which lack
the pselect6 system call.
This new file sysdeps/unix/sysv/linux/microblaze/pselect32.c takes
precedence over the default implementation
sysdeps/unix/sysv/linux/pselect32.c.
However sysdeps/unix/sysv/linux/pselect32.c provides an implementation
of __pselect32() which is needed when __ASSUME_TIME64_SYSCALLS is not
defined. On Microblaze, which is a 32-bit architecture,
__ASSUME_TIME64_SYSCALLS is only true for kernels >= 5.1.
Due to sysdeps/unix/sysv/linux/microblaze/pselect32.c taking
precedence over sysdeps/unix/sysv/linux/pselect32.c, it means that
when we are with a kernel >= 3.15 but < 5.1, we need a __pselect32()
implementation, but sysdeps/unix/sysv/linux/microblaze/pselect32.c
doesn't provide it, and sysdeps/unix/sysv/linux/pselect32.c which
would provide it is not compiled in.
This causes the following build failure on Microblaze with for example
Linux kernel headers 4.9:
/home/thomas/buildroot/buildroot/output/host/lib/gcc/microblazeel-buildroot-linux-gnu/10.3.0/../../../../microblazeel-buildroot-linux-gnu/bin/ld: /home/thomas/buildroot/buildroot/output/build/glibc-2.34-9-g9acab0bba6a5a57323b1f94bf95b21618a9e5aa4/build/libc_pic.os: in function `__pselect64':
(.text+0x120b44): undefined reference to `__pselect32'
collect2: error: ld returned 1 exit status
To fix this, we take a crude approach: replicate in
sysdeps/unix/sysv/linux/microblaze/pselect32.c the
!__ASSUME_TIME64_SYSCALLS implementation that is already in
sysdeps/unix/sysv/linux/pselect32.c.
Upstream: https://sourceware.org/pipermail/libc-alpha/2021-December/134635.html
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
.../unix/sysv/linux/microblaze/pselect32.c | 22 +++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/microblaze/pselect32.c b/sysdeps/unix/sysv/linux/microblaze/pselect32.c
index 70b7b52a48..6b6b3e8a2e 100644
--- a/sysdeps/unix/sysv/linux/microblaze/pselect32.c
+++ b/sysdeps/unix/sysv/linux/microblaze/pselect32.c
@@ -22,7 +22,25 @@
#include <sys/poll.h>
#include <sysdep-cancel.h>
-#ifndef __ASSUME_PSELECT
+#if !defined(__ASSUME_TIME64_SYSCALLS)
+int
+__pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
+ fd_set *exceptfds, const struct __timespec64 *timeout,
+ const sigset_t *sigmask)
+{
+ struct timespec ts32, *pts32 = NULL;
+ if (timeout != NULL)
+ {
+ ts32 = valid_timespec64_to_timespec (*timeout);
+ pts32 = &ts32;
+ }
+
+ return SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds,
+ pts32,
+ ((__syscall_ulong_t[]){ (uintptr_t) sigmask,
+ __NSIG_BYTES }));
+}
+#elif !defined(__ASSUME_PSELECT)
int
__pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
fd_set *exceptfds, const struct __timespec64 *timeout,
@@ -57,4 +75,4 @@ __pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
return ret;
}
-#endif /* __ASSUME_PSELECT */
+#endif
--
2.31.1