Commit 6d1970e1 authored by @wuzhangjin's avatar @wuzhangjin Committed by Willy Tarreau
Browse files

tools/nolibc: add missing my_syscall6() for mips 

It is able to pass the 6th argument like the 5th argument via the stack
for mips, let's add a new my_syscall6() now, see [1] for details:

  The mips/o32 system call convention passes arguments 5 through 8 on
  the user stack.

Both mmap() and pselect6() require my_syscall6().

[1]: https://man7.org/linux/man-pages/man2/syscall.2.html



Signed-off-by: default avatarZhangjin Wu <falcon@tinylab.org>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
parent 8b9bdab6

tools/include/nolibc/arch-mips.h

+26 −1
Original line number Diff line number Diff line
@@ -176,6 +176,31 @@ struct sys_stat_struct { 
	_arg4 ? -_num : _num;                                                 \

})



#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6)                  \

({                                                                            \

	register long _num __asm__ ("v0")  = (num);                           \

	register long _arg1 __asm__ ("a0") = (long)(arg1);                    \

	register long _arg2 __asm__ ("a1") = (long)(arg2);                    \

	register long _arg3 __asm__ ("a2") = (long)(arg3);                    \

	register long _arg4 __asm__ ("a3") = (long)(arg4);                    \

	register long _arg5 = (long)(arg5);                                   \

	register long _arg6 = (long)(arg6);                                   \

									      \

	__asm__ volatile (                                                    \

		"addiu $sp, $sp, -32\n"                                       \

		"sw %7, 16($sp)\n"                                            \

		"sw %8, 20($sp)\n"                                            \

		"syscall\n"                                                   \

		"addiu $sp, $sp, 32\n"                                        \

		: "=r" (_num), "=r"(_arg4)                                    \

		: "0"(_num),                                                  \

		  "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \

		  "r"(_arg6)                                                  \

		: _NOLIBC_SYSCALL_CLOBBERLIST                                 \

	);                                                                    \

	_arg4 ? -_num : _num;                                                 \

})



char **environ __attribute__((weak));

const unsigned long *_auxv __attribute__((weak));

tools/include/nolibc/nolibc.h

+4 −5
Original line number Diff line number Diff line
@@ -13,11 +13,10 @@ 
 * Syscalls are split into 3 levels:

 *   - The lower level is the arch-specific syscall() definition, consisting in

 *     assembly code in compound expressions. These are called my_syscall0() to

 *     my_syscall6() depending on the number of arguments. The MIPS

 *     implementation is limited to 5 arguments. All input arguments are cast

 *     to a long stored in a register. These expressions always return the

 *     syscall's return value as a signed long value which is often either a

 *     pointer or the negated errno value.

 *     my_syscall6() depending on the number of arguments. All input arguments

 *     are castto a long stored in a register. These expressions always return

 *     the syscall's return value as a signed long value which is often either

 *     a pointer or the negated errno value.

 *

 *   - The second level is mostly architecture-independent. It is made of

 *     static functions called sys_<name>() which rely on my_syscallN()