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tools/nolibc: add missing my_syscall6() for mips

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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: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This commit is contained in:
Zhangjin Wu 2023-07-07 22:55:35 +08:00 committed by Willy Tarreau
parent 8b9bdab635
commit 6d1970e1ef
2 changed files with 30 additions and 6 deletions
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27
tools/include/nolibc/arch-mips.h
View File

@ -166,7 +166,7 @@ struct sys_stat_struct {
__asm__ volatile ( \
"addiu $sp, $sp, -32\n" \
"sw %7, 16($sp)\n" \
"syscall\n " \
"syscall\n" \
"addiu $sp, $sp, 32\n" \
: "=r" (_num), "=r"(_arg4) \
: "0"(_num), \
@ -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));

9
tools/include/nolibc/nolibc.h
View File

@ -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()