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Rewrite brk() and sbrk()

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This change reduces the .bss memory requirement for all executables by
O(64kb). The brk system calls are now fully tested and figured out and
might be useful for tiny programs that only target System Five.
This commit is contained in:
Justine Tunney 2022-10-01 23:11:56 -07:00
parent bc8532688b
commit 5005f2e446
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GPG key ID: BE714B4575D6E328
23 changed files with 643 additions and 294 deletions
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49
tool/decode/pe2.c
View file

@ -21,11 +21,13 @@
#include "libc/fmt/conv.h"
#include "libc/intrin/bits.h"
#include "libc/intrin/safemacros.internal.h"
#include "libc/mem/gc.h"
#include "libc/nt/struct/imagedosheader.internal.h"
#include "libc/nt/struct/imagentheaders.internal.h"
#include "libc/nt/struct/imageoptionalheader.internal.h"
#include "libc/mem/gc.h"
#include "libc/nt/struct/imagesectionheader.internal.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
@ -249,6 +251,47 @@ static void ShowIat(char *iat, size_t size) {
}
}
static void ShowSection(struct NtImageSectionHeader *s) {
char name[9] = {0};
memcpy(name, s->Name, 8);
printf("\n");
printf("\t.ascin\t\"%'s\",8\n", name);
printf("\t.long\t%#x\t\t# VirtualSize\n", s->Misc.VirtualSize);
printf("\t.long\t%#x\t\t# VirtualAddress\n", s->VirtualAddress);
printf("\t.long\t%#x\t\t# SizeOfRawData\n", s->SizeOfRawData);
printf("\t.long\t%#x\t\t# PointerToRawData\n", s->PointerToRawData);
printf("\t.long\t%#x\t\t# PointerToRelocations\n", s->PointerToRelocations);
printf("\t.long\t%#x\t\t# PointerToLinenumbers\n", s->PointerToLinenumbers);
printf("\t.short\t%#x\t\t# NumberOfRelocations\n", s->NumberOfRelocations);
printf("\t.short\t%#x\t\t# NumberOfLinenumbers\n", s->NumberOfLinenumbers);
printf("\
// ┌31:Writeable ┌─────────────────────────┐\n\
// │┌30:Readable │ PE Section Flags │\n\
// ││┌29:Executable ├─────────────────────────┤\n\
// │││┌28:Shareable │ o │ for object files │\n\
// ││││┌27:Unpageable │ r │ reserved │\n\
// │││││┌26:Uncacheable └───┴─────────────────────┘\n\
// ││││││┌25:Discardable\n\
// │││││││┌24:Contains Extended Relocations\n\
// ││││││││ ┌15:Contains Global Pointer (GP) Relative Data\n\
// ││││││││ │ ┌7:Contains Uninitialized Data\n\
// ││││││││ │ │┌6:Contains Initialized Data\n\
// ││││││││ o │ ││┌5:Contains Code\n\
// ││││││││┌┴─┐rrrr│ ooror│││rorrr\n\
\t.long\t0b%.32b\t\t# Characteristics\n",
s->Characteristics);
}
static void ShowSections(struct NtImageSectionHeader *s, size_t n) {
size_t i;
printf("\n");
showtitle(basename(path), "windows", "sections", 0, 0);
for (i = 0; i < n; ++i) {
ShowSection(s + i);
}
}
static void showpeheader(struct NtImageNtHeaders *pe) {
showtitle(basename(path), "windows", "pe header", NULL, NULL);
printf("\n");
@ -273,6 +316,10 @@ static void showpeheader(struct NtImageNtHeaders *pe) {
printf("\n");
showpeoptionalheader(pecheckaddress(mz, mzsize, &pe->OptionalHeader,
pe->FileHeader.SizeOfOptionalHeader));
ShowSections(pecheckaddress(mz, mzsize, pe + 1,
pe->FileHeader.NumberOfSections *
sizeof(struct NtImageSectionHeader)),
pe->FileHeader.NumberOfSections);
ShowIat(
(void *)((intptr_t)mz +
pe->OptionalHeader.DataDirectory[kNtImageDirectoryEntryImport]