ref: e16b4d85dd6b1cf14834387b765113114dabeae2
dir: /emu/OpenBSD/asm-amd64.S/
.file "asm-OpenBSD-amd64.S" #include <sys/syscall.h> #include <machine/asm.h> /* * executeonnewstack(void *tos, void (*tramp)(void *arg), void *arg) */ .type ournewstack,@function .global executeonnewstack executeonnewstack: pushq %rbp movq %rsp, %rbp pushq %rsi movq 16(%rbp), %rsi /* get tos */ subq $8, %rsi movq 32(%rbp), %rax movq %rax, (%rsi) /* stash arg on new stack */ subq $8, %rsi movq 24(%rbp), %rax movq %rax, (%rsi) /* stash tramp on new stack */ mov %rsi, %rsp /* swap stacks pronto */ popq %rax /* recover the tramp address */ call *%rax /* and jump to it (ho ho) */ /* if we return here, tramp didn't do it's job */ addq $16, %rsp /* clean up for pose value */ leaq SYS_exit, %rax int $0x80 /* * unlockandexit(int *key) * * NB: the return status may be rubbish if the stack is reused * between the unlock and the system call, but this should * not matter since no task is waiting for the result */ .type unlockandexit,@function .global unlockandexit unlockandexit: pushq %rbp movq %rsp, %rbp movq 16(%rbp), %rsi /* get the key address */ pushq $0 /* exit status 0 */ movq $0, %rax /* unlock the stack allocator */ movq %rax, (%rsi) leaq SYS_exit, %rax /* call exit */ int $0x80 /* * umult(ulong m1, ulong m2, ulong *hi) * umult(rdi, rsi, rdx) - as per system v abi * store rdx in rbp as mul returns the high value in rdx */ .type umult,@function .global umult umult: pushq %rbp movq %rdx, %rbp /* save the 3rd argument (for the high of the result) */ movq %rdi, %rax /* loading the 1st argument */ movq %rsi, %rdx /* loading the 2nd argument */ mul %rdx movq %rdx, (%rbp) popq %rbp ret .type FPsave,@function .global FPsave FPsave: fstenv (%rdi) ret .type FPrestore,@function .global FPrestore FPrestore: fldenv (%rdi) ret .type getcallerpc,@function .global getcallerpc getcallerpc: movq 8(%rbp), %rax ret .type _tas,@function .globl _tas _tas: movl $1, %eax xchgl %eax, 0(%rdi) /* rdi has the first argument to a function */ ret