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author | Palmer Dabbelt <palmer@dabbelt.com> | 2018-01-29 10:27:52 -0800 |
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committer | Palmer Dabbelt <palmer@dabbelt.com> | 2018-01-29 10:27:52 -0800 |
commit | 36960f0c763a904d6d1f028e2c33b7bbe43c2a3a (patch) | |
tree | 39c7b6cf706b27b9cf1939a01b4ac73b6202952a /sysdeps/unix/sysv/linux/riscv/clone.S | |
parent | d1c09b247130c1aedd11b913f579c7764b1b5ae1 (diff) | |
download | glibc-36960f0c763a904d6d1f028e2c33b7bbe43c2a3a.tar.gz glibc-36960f0c763a904d6d1f028e2c33b7bbe43c2a3a.tar.xz glibc-36960f0c763a904d6d1f028e2c33b7bbe43c2a3a.zip |
RISC-V: Linux Syscall Interface
Contains the Linux system call interface, as well as the definitions of a handful of system calls. 2018-01-29 Palmer Dabbelt <palmer@sifive.com> * sysdeps/riscv/nptl/nptl-sysdep.S: New file. * sysdeps/unix/sysv/linux/riscv/arch-fork.h: Likewise. * sysdeps/unix/sysv/linux/riscv/clone.S: Likewise. * sysdeps/unix/sysv/linux/riscv/profil-counter.h: Likewise. * sysdeps/unix/sysv/linux/riscv/pt-vfork.S: Likewise. * sysdeps/unix/sysv/linux/riscv/syscall.c: Likewise. * sysdeps/unix/sysv/linux/riscv/sysdep.S: Likewise. * sysdeps/unix/sysv/linux/riscv/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/riscv/vfork.S: Likewise.
Diffstat (limited to 'sysdeps/unix/sysv/linux/riscv/clone.S')
-rw-r--r-- | sysdeps/unix/sysv/linux/riscv/clone.S | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/riscv/clone.S b/sysdeps/unix/sysv/linux/riscv/clone.S new file mode 100644 index 0000000000..392af72b55 --- /dev/null +++ b/sysdeps/unix/sysv/linux/riscv/clone.S @@ -0,0 +1,86 @@ +/* Wrapper around clone system call. RISC-V version. + Copyright (C) 1996-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +/* clone() is even more special than fork() as it mucks with stacks + and invokes a function in the right context after its all over. */ + +#include <sys/asm.h> +#include <sysdep.h> +#define _ERRNO_H 1 +#include <bits/errno.h> +#include <tls.h> +#include "tcb-offsets.h" + +/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, + void *parent_tidptr, void *tls, void *child_tidptr) */ + + .text +LEAF (__clone) + + /* Sanity check arguments. */ + beqz a0,L (invalid) /* No NULL function pointers. */ + beqz a1,L (invalid) /* No NULL stack pointers. */ + + addi a1,a1,-16 /* Reserve argument save space. */ + REG_S a0,0(a1) /* Save function pointer. */ + REG_S a3,SZREG(a1) /* Save argument pointer. */ + + /* The syscall expects the args to be in different slots. */ + mv a0,a2 + mv a2,a4 + mv a3,a5 + mv a4,a6 + + /* Do the system call. */ + li a7,__NR_clone + scall + + bltz a0,L (error) + beqz a0,L (thread_start) + + /* Successful return from the parent. */ + ret + +L (invalid): + li a0, -EINVAL + /* Something bad happened -- no child created. */ +L (error): + j __syscall_error + END (__clone) + +/* Load up the arguments to the function. Put this block of code in + its own function so that we can terminate the stack trace with our + debug info. */ + +ENTRY (__thread_start) +L (thread_start): + /* Restore the arg for user's function. */ + REG_L a1,0(sp) /* Function pointer. */ + REG_L a0,SZREG(sp) /* Argument pointer. */ + + /* Call the user's function. */ + jalr a1 + + /* Call exit with the function's return value. */ + li a7, __NR_exit + scall + + END (__thread_start) + +libc_hidden_def (__clone) +weak_alias (__clone, clone) |