diff options
Diffstat (limited to 'libc/sysdeps/linux/riscv32/setcontext.S')
| -rw-r--r-- | libc/sysdeps/linux/riscv32/setcontext.S | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/riscv32/setcontext.S b/libc/sysdeps/linux/riscv32/setcontext.S new file mode 100644 index 000000000..15cc17bd8 --- /dev/null +++ b/libc/sysdeps/linux/riscv32/setcontext.S @@ -0,0 +1,112 @@ +/* Set current context. + Copyright (C) 2009-2018 Free Software Foundation, Inc. + + 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/>. */ + +#include "ucontext-macros.h" + +/* int __setcontext (const ucontext_t *ucp) + + Restores the machine context in UCP and thereby resumes execution + in that context. + + This implementation is intended to be used for *synchronous* context + switches only. Therefore, it does not have to restore anything + other than the PRESERVED state. */ + + .text +LEAF (setcontext) + + mv t0, a0 /* Save ucp into t0. */ + +/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */ + li a3, _NSIG8 + mv a2, zero + add a1, a0, UCONTEXT_SIGMASK + li a0, SIG_SETMASK + + li a7, SYS_ify (rt_sigprocmask) + scall + + bltz a0, 99f + + cfi_def_cfa (t0, 0) + +#ifndef __riscv_float_abi_soft + lw t1, MCONTEXT_FSR(t0) + + RESTORE_FP_REG_CFI (fs0, 8, t0) + RESTORE_FP_REG_CFI (fs1, 9, t0) + RESTORE_FP_REG_CFI (fs2, 18, t0) + RESTORE_FP_REG_CFI (fs3, 19, t0) + RESTORE_FP_REG_CFI (fs4, 20, t0) + RESTORE_FP_REG_CFI (fs5, 21, t0) + RESTORE_FP_REG_CFI (fs6, 22, t0) + RESTORE_FP_REG_CFI (fs7, 23, t0) + RESTORE_FP_REG_CFI (fs8, 24, t0) + RESTORE_FP_REG_CFI (fs9, 25, t0) + RESTORE_FP_REG_CFI (fs10, 26, t0) + RESTORE_FP_REG_CFI (fs11, 27, t0) + + fssr t1 +#endif /* __riscv_float_abi_soft */ + + /* Note the contents of argument registers will be random + unless makecontext() has been called. */ + RESTORE_INT_REG (t1, 0, t0) + RESTORE_INT_REG_CFI (ra, 1, t0) + RESTORE_INT_REG (sp, 2, t0) + RESTORE_INT_REG_CFI (s0, 8, t0) + RESTORE_INT_REG_CFI (s1, 9, t0) + RESTORE_INT_REG (a0, 10, t0) + RESTORE_INT_REG (a1, 11, t0) + RESTORE_INT_REG (a2, 12, t0) + RESTORE_INT_REG (a3, 13, t0) + RESTORE_INT_REG (a4, 14, t0) + RESTORE_INT_REG (a5, 15, t0) + RESTORE_INT_REG (a6, 16, t0) + RESTORE_INT_REG (a7, 17, t0) + RESTORE_INT_REG_CFI (s2, 18, t0) + RESTORE_INT_REG_CFI (s3, 19, t0) + RESTORE_INT_REG_CFI (s4, 20, t0) + RESTORE_INT_REG_CFI (s5, 21, t0) + RESTORE_INT_REG_CFI (s6, 22, t0) + RESTORE_INT_REG_CFI (s7, 23, t0) + RESTORE_INT_REG_CFI (s8, 24, t0) + RESTORE_INT_REG_CFI (s9, 25, t0) + RESTORE_INT_REG_CFI (s10, 26, t0) + RESTORE_INT_REG_CFI (s11, 27, t0) + + jr t1 + +99: j __syscall_error + +PSEUDO_END (setcontext) + +LEAF (start_context) + + /* Terminate call stack by noting ra == 0. Happily, s0 == 0 here. */ + cfi_register (ra, s0) + + /* Call the function passed to makecontext. */ + jalr s1 + + /* Invoke subsequent context if present, else exit(0). */ + mv a0, s2 + beqz s2, 1f + jal setcontext +1: j exit + +PSEUDO_END (start_context) |