| 1 | From 911bf867eb82e28799e81578c50d82ee166cebb5 Mon Sep 17 00:00:00 2001 |
| 2 | From: Gabor Juhos <juhosg@openwrt.org> |
| 3 | Date: Tue, 6 Apr 2010 17:25:56 +0200 |
| 4 | Subject: [PATCH] MIPS: restore INLINE_SYSCALL macro |
| 5 | |
| 6 | The MIPS specific INLINE_SYSCALL macro has been renamed to |
| 7 | INLINE_SYSCALL_NCS with: |
| 8 | |
| 9 | 763bbf9e9a27426c9be8322dca5ddf2cb4dbc464 |
| 10 | |
| 11 | syscall: unify part 2: NCS variety |
| 12 | |
| 13 | Declare common NCS (non-constant syscall) variants and convert the |
| 14 | existing ports over to this. |
| 15 | |
| 16 | This change breaks system calls. The code generated with using of the |
| 17 | new macro does not obey the restartable syscall convention used by the |
| 18 | linux kernel. When it tries to restart the syscall the errno value is |
| 19 | not being replaced by the syscall number. |
| 20 | |
| 21 | This causes weird behaviour of the 'ping' command in busybox for |
| 22 | example: |
| 23 | |
| 24 | root@OpenWrt:/# ping 192.168.1.254 |
| 25 | PING 192.168.1.254 (192.168.1.254): 56 data bytes |
| 26 | 64 bytes from 192.168.1.254: seq=0 ttl=128 time=6.292 ms |
| 27 | ping: recvfrom: Function not implemented |
| 28 | 64 bytes from 192.168.1.254: seq=1 ttl=128 time=0.719 ms |
| 29 | ping: recvfrom: Function not implemented |
| 30 | 64 bytes from 192.168.1.254: seq=2 ttl=128 time=0.489 ms |
| 31 | ping: recvfrom: Function not implemented |
| 32 | 64 bytes from 192.168.1.254: seq=3 ttl=128 time=0.486 ms |
| 33 | ping: recvfrom: Function not implemented |
| 34 | 64 bytes from 192.168.1.254: seq=4 ttl=128 time=0.487 ms |
| 35 | ping: recvfrom: Function not implemented |
| 36 | 64 bytes from 192.168.1.254: seq=5 ttl=128 time=0.939 ms |
| 37 | ping: recvfrom: Function not implemented |
| 38 | 64 bytes from 192.168.1.254: seq=6 ttl=128 time=0.971 ms |
| 39 | ping: recvfrom: Function not implemented |
| 40 | 64 bytes from 192.168.1.254: seq=7 ttl=128 time=0.488 ms |
| 41 | ping: recvfrom: Funct^C |
| 42 | --- 192.168.1.254 ping statistics --- |
| 43 | 9 packets transmitted, 9 packets received, 0% packet loss |
| 44 | round-trip min/avg/max = 0.486/1.307/6.292 ms |
| 45 | root@OpenWrt:/# |
| 46 | |
| 47 | Here is the relevant assembler code parts of the 'recvfrom' function: |
| 48 | |
| 49 | with the current INLINE_SYSCALL_NCS: |
| 50 | 00000000 <__GI_recvfrom>: |
| 51 | ... |
| 52 | 2c: 24021050 li v0,4176 |
| 53 | 30: 8fd1003c lw s1,60(s8) |
| 54 | 34: 8fd00038 lw s0,56(s8) |
| 55 | 38: 27bdffe0 addiu sp,sp,-32 |
| 56 | 3c: afb00010 sw s0,16(sp) |
| 57 | 40: afb10014 sw s1,20(sp) <-- wrong |
| 58 | 44: 0000000c syscall |
| 59 | 48: 27bd0020 addiu sp,sp,32 |
| 60 | ... |
| 61 | |
| 62 | with the old INLINE_SYSCALL: |
| 63 | 00000000 <__libc_recvfrom>: |
| 64 | ... |
| 65 | 28: 8fd0003c lw s0,60(s8) |
| 66 | 2c: 8fc20038 lw v0,56(s8) |
| 67 | 30: 27bdffe0 addiu sp,sp,-32 |
| 68 | 34: afa20010 sw v0,16(sp) |
| 69 | 38: afb00014 sw s0,20(sp) |
| 70 | 3c: 24021050 li v0,4176 <-- good |
| 71 | 40: 0000000c syscall |
| 72 | 44: 27bd0020 addiu sp,sp,32 |
| 73 | ... |
| 74 | |
| 75 | Signed-off-by: Gabor Juhos <juhosg@openwrt.org> |
| 76 | Cc: Mike Frysinger <vapier@gentoo.org> |
| 77 | --- |
| 78 | Notes: |
| 79 | |
| 80 | The ideal solution would to fix the 'internal_syscall' macros to generate |
| 81 | correct code for the NCS case as well. However the INLINE_SYSCALL macro |
| 82 | generates smaller code if the syscall number is constant, so it is |
| 83 | useful in such cases. |
| 84 | |
| 85 | Additionally, the current INLINE_SYSCALL_NCS in the 'mips/bits/syscall.h' |
| 86 | is a duplicate of the one in the 'common/bits/syscalls-common.h' so it |
| 87 | should be removed anyway. |
| 88 | --- |
| 89 | libc/sysdeps/linux/mips/bits/syscalls.h | 4 ++-- |
| 90 | 1 files changed, 2 insertions(+), 2 deletions(-) |
| 91 | |
| 92 | diff --git a/libc/sysdeps/linux/mips/bits/syscalls.h b/libc/sysdeps/linux/mips/bits/syscalls.h |
| 93 | index 28b0f91..944d038 100644 |
| 94 | --- a/libc/sysdeps/linux/mips/bits/syscalls.h |
| 95 | +++ b/libc/sysdeps/linux/mips/bits/syscalls.h |
| 96 | @@ -19,9 +19,9 @@ |
| 97 | |
| 98 | /* Define a macro which expands into the inline wrapper code for a system |
| 99 | call. */ |
| 100 | -#define INLINE_SYSCALL_NCS(name, nr, args...) \ |
| 101 | +#define INLINE_SYSCALL(name, nr, args...) \ |
| 102 | ({ INTERNAL_SYSCALL_DECL(err); \ |
| 103 | - long result_var = INTERNAL_SYSCALL_NCS (name, err, nr, args); \ |
| 104 | + long result_var = INTERNAL_SYSCALL(name, err, nr, args); \ |
| 105 | if ( INTERNAL_SYSCALL_ERROR_P (result_var, err) ) \ |
| 106 | { \ |
| 107 | __set_errno (INTERNAL_SYSCALL_ERRNO (result_var, err)); \ |
| 108 | -- |
| 109 | 1.5.3.2 |
| 110 | |
| 111 | |
