toolchain/uClubc-0.9.31: fix syscalls on MIPS

SVN-Revision: 20882

toolchain/uClibc/patches-0.9.31/901-MIPS-restore-INLINE_SYSCALL-macro.patch

@@ -0,0 +1,110 @@
+From 911bf867eb82e28799e81578c50d82ee166cebb5 Mon Sep 17 00:00:00 2001
+From: Gabor Juhos <juhosg@openwrt.org>
+Date: Tue, 6 Apr 2010 17:25:56 +0200
+Subject: [PATCH] MIPS: restore INLINE_SYSCALL macro
+
+The MIPS specific INLINE_SYSCALL macro has been renamed to
+INLINE_SYSCALL_NCS with:
+
+  763bbf9e9a27426c9be8322dca5ddf2cb4dbc464
+
+  syscall: unify part 2: NCS variety
+
+  Declare common NCS (non-constant syscall) variants and convert the
+  existing ports over to this.
+
+This change breaks system calls. The code generated with using of the
+new macro does not obey the restartable syscall convention used by the
+linux kernel. When it tries to restart the syscall the errno value is
+not being replaced by the syscall number.
+
+This causes weird behaviour of the 'ping' command in busybox for
+example:
+
+root@OpenWrt:/# ping 192.168.1.254
+PING 192.168.1.254 (192.168.1.254): 56 data bytes
+64 bytes from 192.168.1.254: seq=0 ttl=128 time=6.292 ms
+ping: recvfrom: Function not implemented
+64 bytes from 192.168.1.254: seq=1 ttl=128 time=0.719 ms
+ping: recvfrom: Function not implemented
+64 bytes from 192.168.1.254: seq=2 ttl=128 time=0.489 ms
+ping: recvfrom: Function not implemented
+64 bytes from 192.168.1.254: seq=3 ttl=128 time=0.486 ms
+ping: recvfrom: Function not implemented
+64 bytes from 192.168.1.254: seq=4 ttl=128 time=0.487 ms
+ping: recvfrom: Function not implemented
+64 bytes from 192.168.1.254: seq=5 ttl=128 time=0.939 ms
+ping: recvfrom: Function not implemented
+64 bytes from 192.168.1.254: seq=6 ttl=128 time=0.971 ms
+ping: recvfrom: Function not implemented
+64 bytes from 192.168.1.254: seq=7 ttl=128 time=0.488 ms
+ping: recvfrom: Funct^C
+--- 192.168.1.254 ping statistics ---
+9 packets transmitted, 9 packets received, 0% packet loss
+round-trip min/avg/max = 0.486/1.307/6.292 ms
+root@OpenWrt:/#
+
+Here is the relevant assembler code parts of the 'recvfrom' function:
+
+with the current INLINE_SYSCALL_NCS:
+00000000 <__GI_recvfrom>:
+  ...
+  2c:   24021050        li      v0,4176
+  30:   8fd1003c        lw      s1,60(s8)
+  34:   8fd00038        lw      s0,56(s8)
+  38:   27bdffe0        addiu   sp,sp,-32
+  3c:   afb00010        sw      s0,16(sp)
+  40:   afb10014        sw      s1,20(sp)  <-- wrong
+  44:   0000000c        syscall
+  48:   27bd0020        addiu   sp,sp,32
+  ...
+
+with the old INLINE_SYSCALL:
+00000000 <__libc_recvfrom>:
+  ...
+  28:   8fd0003c        lw      s0,60(s8)
+  2c:   8fc20038        lw      v0,56(s8)
+  30:   27bdffe0        addiu   sp,sp,-32
+  34:   afa20010        sw      v0,16(sp)
+  38:   afb00014        sw      s0,20(sp)
+  3c:   24021050        li      v0,4176   <-- good
+  40:   0000000c        syscall
+  44:   27bd0020        addiu   sp,sp,32
+  ...
+
+Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
+Cc: Mike Frysinger <vapier@gentoo.org>
+---
+Notes:
+
+The ideal solution would to fix the 'internal_syscall' macros to generate
+correct code for the NCS case as well. However the INLINE_SYSCALL macro
+generates smaller code if the syscall number is constant, so it is
+useful in such cases.
+
+Additionally, the current INLINE_SYSCALL_NCS in the 'mips/bits/syscall.h'
+is a duplicate of the one in the 'common/bits/syscalls-common.h' so it
+should be removed anyway.
+---
+ libc/sysdeps/linux/mips/bits/syscalls.h |    4 ++--
+ 1 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/libc/sysdeps/linux/mips/bits/syscalls.h b/libc/sysdeps/linux/mips/bits/syscalls.h
+index 28b0f91..944d038 100644
+--- a/libc/sysdeps/linux/mips/bits/syscalls.h
++++ b/libc/sysdeps/linux/mips/bits/syscalls.h
+@@ -19,9 +19,9 @@
+ 
+ /* Define a macro which expands into the inline wrapper code for a system
+    call.  */
+-#define INLINE_SYSCALL_NCS(name, nr, args...)                               \
++#define INLINE_SYSCALL(name, nr, args...)                               \
+   ({ INTERNAL_SYSCALL_DECL(err);					\
+-     long result_var = INTERNAL_SYSCALL_NCS (name, err, nr, args);		\
++     long result_var = INTERNAL_SYSCALL(name, err, nr, args);		\
+      if ( INTERNAL_SYSCALL_ERROR_P (result_var, err) )			\
+        {								\
+ 	 __set_errno (INTERNAL_SYSCALL_ERRNO (result_var, err));	\
+-- 
+1.5.3.2
+