cosmopolitan/libc/log/shadowargs.greg.c

59 lines
3.1 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program 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 │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/log/log.h"
#include "libc/log/shadowargs.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/symbols.h"
alignas(1) const
char __shadowargs_slotnames[SHADOWARGS_SLOTS][SHADOWARGS_MAXNAME] = {
"func", "%rsp", "%rdi", "%rsi", "%rdx", "%rcx", "%r8", "%r9",
};
alignas(64) struct ShadowArgs __shadowargs[SHADOWARGS_COUNT];
unsigned __shadowargs_index;
nocallersavedregisters void __fentry__(uint64_t rdi, uint64_t rsi, uint64_t rdx,
uint64_t rcx, uint64_t r8, uint64_t r9) {
void *addr = __builtin_return_address(0);
intptr_t frame = (intptr_t)__builtin_frame_address(0);
unsigned i = __shadowargs_index;
intptr_t lastframe = (intptr_t)__shadowargs[i].frame;
if (frame < lastframe) {
i--;
i &= SHADOWARGS_COUNT - 1;
} else if (frame > lastframe) {
unsigned j = i;
do {
j++;
j &= SHADOWARGS_COUNT - 1;
} while (frame > (intptr_t)__shadowargs[j].frame && j != i);
i = j;
}
__shadowargs[i].addr = addr;
__shadowargs[i].frame = (void *)frame;
__shadowargs[i].arg1 = rdi;
__shadowargs[i].arg2 = rsi;
__shadowargs[i].arg3 = rdx;
__shadowargs[i].arg4 = rcx;
__shadowargs[i].arg5 = r8;
__shadowargs[i].arg6 = r9;
__shadowargs_index = i;
}