From a7e8c6aa9b192075f17774c0bbdf6829f41ba62f Mon Sep 17 00:00:00 2001 From: Waldemar Brodkorb Date: Sat, 21 Dec 2013 13:18:29 +0100 Subject: libc: fix MIPS N64 fork fork() is broken for MIPS64 N64 ABI. You can check it with a simple C program statically linked with qemu-mips64 user emulation. Internally fork() is using the clone system call (at least with NPTL) with 5 arguments. See ./libpthread/nptl/sysdeps/unix/sysv/linux/i386/fork.c. The calling conventions for MIPS N32 and N64 allow to use up to 8 registers for that. See http://en.wikipedia.org/wiki/Calling_convention#MIPS This is correctly implemented in libc/sysdeps/linux/mips/bits/syscalls.h, but not in libc/sysdeps/linux/mips/sysdep.h. fork.c uses the later one. It seems that fork() works fine for MIPS64 N32 with just using the stack like with the O32 case. There is a user of INLINE_SYSCALL with 7 arguments in libc/sysdeps/linux/common/sync_file_range.c for MIPS64 N32, so I decided to only use the macros for the MIPS64 N64 case. With this patch my uClibc based Linux system boots up fine in qemu-system-mips64. Signed-off-by: Waldemar Brodkorb Signed-off-by: Bernhard Reutner-Fischer --- libc/sysdeps/linux/mips/sysdep.h | 63 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/libc/sysdeps/linux/mips/sysdep.h b/libc/sysdeps/linux/mips/sysdep.h index 6dba1fbf1..46b6c5376 100644 --- a/libc/sysdeps/linux/mips/sysdep.h +++ b/libc/sysdeps/linux/mips/sysdep.h @@ -279,6 +279,8 @@ L(syse1): _sys_result; \ }) +#if _MIPS_SIM == _ABIO32 || _MIPS_SIM == _ABIN32 + /* We need to use a frame pointer for the functions in which we adjust $sp around the syscall, or debug information and unwind information will be $sp relative and thus wrong during the syscall. As @@ -382,6 +384,67 @@ L(syse1): #define __SYSCALL_CLOBBERS "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", \ "$14", "$15", "$24", "$25", "memory" +#else /* N64 */ + +#undef internal_syscall5 +#define internal_syscall5(ncs_init, cs_init, input, err, arg1, arg2, arg3, arg4, arg5) \ +({ \ + long _sys_result; \ + \ + { \ + register long __v0 __asm__("$2") ncs_init; \ + register long __a0 __asm__("$4") = (long) arg1; \ + register long __a1 __asm__("$5") = (long) arg2; \ + register long __a2 __asm__("$6") = (long) arg3; \ + register long __a3 __asm__("$7") = (long) arg4; \ + register long __a4 __asm__("$8") = (long) arg5; \ + __asm__ __volatile__ ( \ + ".set\tnoreorder\n\t" \ + cs_init \ + "syscall\n\t" \ + ".set\treorder" \ + : "=r" (__v0), "+r" (__a3) \ + : input, "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a4) \ + : __SYSCALL_CLOBBERS); \ + err = __a3; \ + _sys_result = __v0; \ + } \ + _sys_result; \ +}) + +#undef internal_syscall6 +#define internal_syscall6(ncs_init, cs_init, input, err, arg1, arg2, arg3, arg4, arg5, arg6) \ +({ \ + long _sys_result; \ + \ + { \ + register long __v0 __asm__("$2") ncs_init; \ + register long __a0 __asm__("$4") = (long) arg1; \ + register long __a1 __asm__("$5") = (long) arg2; \ + register long __a2 __asm__("$6") = (long) arg3; \ + register long __a3 __asm__("$7") = (long) arg4; \ + register long __a4 __asm__("$8") = (long) arg5; \ + register long __a5 __asm__("$9") = (long) arg6; \ + __asm__ __volatile__ ( \ + ".set\tnoreorder\n\t" \ + cs_init \ + "syscall\n\t" \ + ".set\treorder" \ + : "=r" (__v0), "+r" (__a3) \ + : input, "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a4), \ + "r" (__a5) \ + : __SYSCALL_CLOBBERS); \ + err = __a3; \ + _sys_result = __v0; \ + } \ + _sys_result; \ +}) + +#define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \ + "$14", "$15", "$24", "$25", "hi", "lo", "memory" + +#endif + /* Pointer mangling is not yet supported for MIPS. */ #define PTR_MANGLE(var) (void) (var) #define PTR_DEMANGLE(var) (void) (var) -- cgit v1.2.3