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Work towards zipos / open(argv[0]) on metal (#667)

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tkchia 2022-11-06 15:29:47 +08:00 • committed by GitHub
parent 543c93f623
commit cb9a0466f1
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GPG key ID: 4AEE18F83AFDEB23
17 changed files with 257 additions and 46 deletions
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67
libc/intrin/directmap-metal.c
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@ -18,28 +18,56 @@
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/intrin/directmap.internal.h"
#include "libc/calls/internal.h"
#include "libc/calls/metalfile.internal.h"
#include "libc/macros.internal.h"
#include "libc/runtime/pc.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/errfuns.h"
#define MAP_ANONYMOUS_linux 0x00000020
#define MAP_FIXED_linux 0x00000010
static uint64_t sys_mmap_metal_break;
noasan struct DirectMap sys_mmap_metal(void *paddr, size_t size, int prot,
noasan static struct DirectMap bad_mmap(void) {
struct DirectMap res;
res.addr = (void *)-1;
res.maphandle = -1;
return res;
}
noasan struct DirectMap sys_mmap_metal(void *vaddr, size_t size, int prot,
int flags, int fd, int64_t off) {
/* asan runtime depends on this function */
size_t i;
struct mman *mm;
struct DirectMap res;
uint64_t addr, page, *pte, *pml4t;
uint64_t addr, faddr = 0, page, *pte, *fdpte, *pml4t;
mm = (struct mman *)(BANE + 0x0500);
pml4t = __get_pml4t();
size = ROUNDUP(size, 4096);
addr = (uint64_t)paddr;
if (!(flags & MAP_FIXED)) {
if (!addr) addr = 4096;
addr = (uint64_t)vaddr;
if (!(flags & MAP_ANONYMOUS_linux)) {
struct Fd *sfd;
struct MetalFile *file;
if (off < 0 || fd < 0 || fd >= g_fds.n) return bad_mmap();
sfd = &g_fds.p[fd];
if (sfd->kind != kFdFile) return bad_mmap();
file = (struct MetalFile *)sfd->handle;
/* TODO: allow mapping partial page at end of file, if file size not
* multiple of page size */
if (off > file->size || size > file->size - off) return bad_mmap();
faddr = (uint64_t)file->base + off;
if (faddr % 4096 != 0) return bad_mmap();
}
if (!(flags & MAP_FIXED_linux)) {
if (!addr) {
addr = 4096;
} else {
addr = ROUNDUP(addr, 4096);
}
for (i = 0; i < size; i += 4096) {
pte = __get_virtual(mm, pml4t, addr + i, false);
if (pte && (*pte & (PAGE_V | PAGE_RSRV))) {
@ -52,15 +80,26 @@ noasan struct DirectMap sys_mmap_metal(void *paddr, size_t size, int prot,
for (i = 0; i < size; i += 4096) {
page = __new_page(mm);
pte = __get_virtual(mm, pml4t, addr + i, true);
if (pte && page) {
__clear_page(BANE + page);
page |= PAGE_RSRV | PAGE_U;
if ((prot & PROT_WRITE))
page |= PAGE_V | PAGE_RW;
else if ((prot & (PROT_READ | PROT_EXEC)))
page |= PAGE_V;
if (!(prot & PROT_EXEC)) page |= PAGE_XD;
if (pte) {
if ((flags & MAP_ANONYMOUS_linux)) {
page = __new_page(mm);
if (!page) return bad_mmap();
__clear_page(BANE + page);
page |= PAGE_RSRV | PAGE_U;
if ((prot & PROT_WRITE))
page |= PAGE_V | PAGE_RW;
else if ((prot & (PROT_READ | PROT_EXEC)))
page |= PAGE_V;
if (!(prot & PROT_EXEC)) page |= PAGE_XD;
} else {
fdpte = __get_virtual(mm, pml4t, faddr + i, false);
page = *fdpte;
page |= PAGE_RSRV | PAGE_U;
if (!(prot & PROT_WRITE)) page &= ~PAGE_RW;
if (!(prot & PROT_EXEC)) page |= PAGE_XD;
}
*pte = page;
invlpg(addr + i);
} else {
addr = -1;
break;