diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/riscv/makecontext.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/riscv/makecontext.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/riscv/makecontext.c b/sysdeps/unix/sysv/linux/riscv/makecontext.c new file mode 100644 index 0000000000..b8054a29b0 --- /dev/null +++ b/sysdeps/unix/sysv/linux/riscv/makecontext.c @@ -0,0 +1,78 @@ +/* Create new context. RISC-V version. + Copyright (C) 2001-2018 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/>. */ + +#include <sysdep.h> +#include <sys/asm.h> +#include <sys/ucontext.h> +#include <stdarg.h> +#include <assert.h> + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, + long int a0, long int a1, long int a2, long int a3, long int a4, + ...) +{ + extern void __start_context (void) attribute_hidden; + long int i, sp; + + _Static_assert (REG_NARGS == 8, "__makecontext assumes 8 argument registers"); + + /* Set up the stack. */ + sp = ((long int) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & ALMASK; + + /* Set up the register context. + ra = s0 = 0, terminating the stack for backtracing purposes. + s1 = the function we must call. + s2 = the subsequent context to run. */ + ucp->uc_mcontext.__gregs[REG_RA] = 0; + ucp->uc_mcontext.__gregs[REG_S0] = 0; + ucp->uc_mcontext.__gregs[REG_S1] = (long int) func; + ucp->uc_mcontext.__gregs[REG_S2] = (long int) ucp->uc_link; + ucp->uc_mcontext.__gregs[REG_SP] = sp; + ucp->uc_mcontext.__gregs[REG_PC] = (long int) &__start_context; + + /* Put args in a0-a7, then put any remaining args on the stack. */ + ucp->uc_mcontext.__gregs[REG_A0 + 0] = a0; + ucp->uc_mcontext.__gregs[REG_A0 + 1] = a1; + ucp->uc_mcontext.__gregs[REG_A0 + 2] = a2; + ucp->uc_mcontext.__gregs[REG_A0 + 3] = a3; + ucp->uc_mcontext.__gregs[REG_A0 + 4] = a4; + + if (__glibc_unlikely (argc > 5)) + { + va_list vl; + va_start (vl, a4); + + long reg_args = argc < REG_NARGS ? argc : REG_NARGS; + for (i = 5; i < reg_args; i++) + ucp->uc_mcontext.__gregs[REG_A0 + i] = va_arg (vl, long); + + long int stack_args = argc - reg_args; + if (stack_args > 0) + { + sp = (sp - stack_args * sizeof (long int)) & ALMASK; + ucp->uc_mcontext.__gregs[REG_SP] = sp; + for (i = 0; i < stack_args; i++) + ((long int *) sp)[i] = va_arg (vl, long int); + } + + va_end (vl); + } +} + +weak_alias (__makecontext, makecontext) |