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-rw-r--r--toys/pending/readelf.c203
1 files changed, 119 insertions, 84 deletions
diff --git a/toys/pending/readelf.c b/toys/pending/readelf.c
index 5cd148c1..a8564a4d 100644
--- a/toys/pending/readelf.c
+++ b/toys/pending/readelf.c
@@ -35,7 +35,7 @@ GLOBALS(
char *x, *p;
char *elf, *shstrtab, *f;
- unsigned long long shoff, phoff, size;
+ unsigned long long shoff, phoff, size, shstrtabsz;
int bits, endian, shnum, shentsize, phentsize;
)
@@ -75,13 +75,14 @@ static unsigned short elf_short(char **p)
return elf_get(p, 2);
}
-static void get_sh(int i, struct sh *s)
+static int get_sh(unsigned i, struct sh *s)
{
char *shdr = TT.elf+TT.shoff+i*TT.shentsize;
- int name_offset;
+ unsigned name_offset;
if (i >= TT.shnum || shdr > TT.elf+TT.size-TT.shentsize) {
- error_exit("%s: no shdr %d",TT.f,i);
+ printf("No shdr %d\n", i);
+ return 0;
}
name_offset = elf_int(&shdr);
@@ -95,14 +96,21 @@ static void get_sh(int i, struct sh *s)
s->addralign = elf_long(&shdr);
s->entsize = elf_long(&shdr);
+ if (s->offset>TT.size || s->size>TT.size || s->offset>TT.size-s->size) {
+ printf("Bad offset/size %llu/%llu for sh %d\n", s->offset, s->size, i);
+ return 0;
+ }
+
if (!TT.shstrtab) s->name = "?";
else {
s->name = TT.shstrtab + name_offset;
- if (s->name >= TT.elf+TT.size) error_exit("%s: shdr %d bad name", TT.f, i);
- if (s->offset >= TT.size-s->size && s->type != 8 /*SHT_NOBITS*/)
- error_exit("%s: shdr %d has bad offset/size %llu/%llu", TT.f, i,
- s->offset, s->size);
+ if (name_offset > TT.shstrtabsz || s->name >= TT.elf+TT.size) {
+ printf("Bad name for sh %d\n", i);
+ return 0;
+ }
}
+
+ return 1;
}
static int find_section(char *spec, struct sh *s)
@@ -113,26 +121,25 @@ static int find_section(char *spec, struct sh *s)
// Valid section number?
errno = 0;
i = strtoul(spec, &end, 0);
- if (!errno && !*end && i < TT.shnum) {
- get_sh(i, s);
- return 1;
- }
+ if (!errno && !*end && i < TT.shnum) return get_sh(i, s);
// Search the section names.
for (i=0; i<TT.shnum; i++) {
- get_sh(i, s);
- if (!strcmp(s->name, spec)) return 1;
+ if (get_sh(i, s) && !strcmp(s->name, spec)) return 1;
}
error_msg("%s: no section '%s", TT.f, spec);
return 0;
}
-static void get_ph(int i, struct ph *ph)
+static int get_ph(int i, struct ph *ph)
{
char *phdr = TT.elf+TT.phoff+i*TT.phentsize;
- if (phdr > TT.elf+TT.size-TT.phentsize) error_exit("%s: no phdr %d",TT.f,i);
+ if (phdr > TT.elf+TT.size-TT.phentsize) {
+ printf("Bad phdr %d\n", i);
+ return 0;
+ }
// Elf64_Phdr reordered fields.
ph->type = elf_int(&phdr);
@@ -154,9 +161,12 @@ static void get_ph(int i, struct ph *ph)
ph->align = elf_int(&phdr);
}
- if (ph->offset >= TT.size-ph->filesz)
- error_exit("%s: phdr %d has bad offset/size %llu/%llu", TT.f, i,
- ph->offset, ph->filesz);
+ if (ph->offset >= TT.size-ph->filesz) {
+ printf("phdr %d has bad offset/size %llu/%llu", i, ph->offset, ph->filesz);
+ return 0;
+ }
+
+ return 1;
}
#define MAP(...) __VA_ARGS__
@@ -238,9 +248,9 @@ static void show_symbols(struct sh *table, struct sh *strtab)
" Num: %*s Size Type Bind Vis Ndx Name\n",
table->name, numsym, 5+8*TT.bits, "Value");
for (i=0; i<numsym; i++) {
- int st_name = elf_int(&symtab), st_value, st_shndx;
+ unsigned st_name = elf_int(&symtab), st_value, st_shndx;
unsigned char st_info, st_other;
- long st_size;
+ unsigned long st_size;
char *name;
// The various fields were moved around for 64-bit.
@@ -259,7 +269,7 @@ static void show_symbols(struct sh *table, struct sh *strtab)
}
name = TT.elf + strtab->offset + st_name;
- if (name >= TT.elf+TT.size) error_exit("%s: bad symbol name", TT.f);
+ if (name >= TT.elf+TT.size) name = "???";
if (!st_shndx) ndx = "UND";
else if (st_shndx==0xfff1) ndx = "ABS";
@@ -267,7 +277,7 @@ static void show_symbols(struct sh *table, struct sh *strtab)
// TODO: look up and show any symbol versions with @ or @@.
- printf("%6d: %0*x %5ld %-7s %-6s %-9s%3s %s\n", i, 8*(TT.bits+1),
+ printf("%6d: %0*x %5lu %-7s %-6s %-9s%3s %s\n", i, 8*(TT.bits+1),
st_value, st_size, stt_type(st_info & 0xf), stb_type(st_info >> 4),
stv_type(st_other & 3), ndx, name);
}
@@ -280,15 +290,24 @@ static int notematch(int namesz, char **p, char *expected, int len)
return 1;
}
-static void show_notes(long offset, long size)
+static void show_notes(unsigned long offset, unsigned long size)
{
char *note = TT.elf + offset;
+ if (size > TT.size || offset > TT.size-size) {
+ printf("Bad note bounds %lu/%lu\n", offset, size);
+ return;
+ }
+
printf(" %-20s %10s\tDescription\n", "Owner", "Data size");
while (note < TT.elf+offset+size) {
char *p = note, *desc;
- int namesz = elf_int(&p), descsz = elf_int(&p), type = elf_int(&p), j = 0;
+ unsigned namesz=elf_int(&p), descsz=elf_int(&p), type=elf_int(&p), j=0;
+ if (namesz > size || descsz > size) {
+ error_msg("%s: bad note @%lu", TT.f, offset);
+ return;
+ }
printf(" %-20.*s 0x%08x\t", namesz, p, descsz);
if (notematch(namesz, &p, "GNU", 4)) {
if (type == 1) {
@@ -356,18 +375,6 @@ static void scan_elf()
TT.shnum = elf_short(&hdr);
shstrndx = elf_short(&hdr);
- // Set up the section header string table so we can use section header names.
- // Core files have shstrndx == 0.
- TT.shstrtab = 0;
- if (shstrndx != 0) {
- get_sh(shstrndx, &shstr);
- if (shstr.type != 3 /*SHT_STRTAB*/) {
- error_msg("%s: bad shstrndx", TT.f);
- return;
- }
- TT.shstrtab = TT.elf+shstr.offset;
- }
-
if (toys.optc > 1) printf("\nFile: %s\n", TT.f);
if (FLAG(h)) {
@@ -384,9 +391,9 @@ static void scan_elf()
printf(" Machine: %s\n", elf_arch_name(machine));
printf(" Version: 0x%x\n", version);
printf(" Entry point address: 0x%x\n", entry);
- printf(" Start of program headers: %lld (bytes into file)\n",
+ printf(" Start of program headers: %llu (bytes into file)\n",
TT.phoff);
- printf(" Start of section headers: %lld (bytes into file)\n",
+ printf(" Start of section headers: %llu (bytes into file)\n",
TT.shoff);
printf(" Flags: 0x%x\n", flags);
printf(" Size of this header: %d (bytes)\n", ehsize);
@@ -396,6 +403,27 @@ static void scan_elf()
printf(" Number of section headers: %d\n", TT.shnum);
printf(" Section header string table index: %d\n", shstrndx);
}
+ if (TT.phoff > TT.size) {
+ error_msg("%s: bad phoff", TT.f);
+ return;
+ }
+ if (TT.shoff > TT.size) {
+ error_msg("%s: bad shoff", TT.f);
+ return;
+ }
+
+ // Set up the section header string table so we can use section header names.
+ // Core files have shstrndx == 0.
+ TT.shstrtab = 0;
+ TT.shstrtabsz = 0;
+ if (shstrndx != 0) {
+ if (!get_sh(shstrndx, &shstr) || shstr.type != 3 /*SHT_STRTAB*/) {
+ error_msg("%s: bad shstrndx", TT.f);
+ return;
+ }
+ TT.shstrtab = TT.elf+shstr.offset;
+ TT.shstrtabsz = shstr.size;
+ }
w = 8*(TT.bits+1);
if (FLAG(S)) {
@@ -414,7 +442,7 @@ static void scan_elf()
// We need to iterate through the section headers even if we're not
// dumping them, to find specific sections.
for (i=0; i<TT.shnum; i++) {
- get_sh(i, &s);
+ if (!get_sh(i, &s)) continue;
if (s.type == 2 /*SHT_SYMTAB*/) symtab = s;
else if (s.type == 6 /*SHT_DYNAMIC*/) dynamic = s;
else if (s.type == 11 /*SHT_DYNSYM*/) dynsym = s;
@@ -453,12 +481,13 @@ static void scan_elf()
" %-14s %-8s %-*s %-*s %-7s %-7s Flg Align\n", "Type",
"Offset", w, "VirtAddr", w, "PhysAddr", "FileSiz", "MemSiz");
for (i=0; i<phnum; i++) {
- get_ph(i, &ph);
+ if (!get_ph(i, &ph)) continue;
printf(" %-14s 0x%06llx 0x%0*llx 0x%0*llx 0x%05llx 0x%05llx %c%c%c %#llx\n",
ph_type(ph.type), ph.offset, w, ph.vaddr, w, ph.paddr,
ph.filesz, ph.memsz, ph.flags&4?'R':' ', ph.flags&2?'W':' ',
ph.flags&1?'E':' ', ph.align);
- if (ph.type == 3 /*PH_INTERP*/ && ph.filesz - 1 < TT.size - ph.offset) {
+ if (ph.type == 3 /*PH_INTERP*/ && ph.filesz<TT.size &&
+ ph.offset<TT.size && ph.filesz - 1 < TT.size - ph.offset) {
printf(" [Requesting program interpreter: %*s]\n",
(int) ph.filesz-1, TT.elf+ph.offset);
}
@@ -468,10 +497,10 @@ static void scan_elf()
" Section to Segment mapping:\n"
" Segment Sections...\n");
for (i=0; i<phnum; i++) {
- get_ph(i, &ph);
+ if (!get_ph(i, &ph)) continue;
printf(" %02d ", i);
for (j=0; j<TT.shnum; j++) {
- get_sh(j, &s);
+ if (!get_sh(j, &s)) continue;
if (!*s.name) continue;
if (s.offset >= ph.offset && s.offset+s.size <= ph.offset+ph.filesz)
printf("%s ", s.name);
@@ -488,45 +517,51 @@ static void scan_elf()
xputc('\n');
if (!dynamic.size) printf("There is no dynamic section in this file.\n");
- else printf("Dynamic section at offset 0x%llx contains %lld entries:\n"
- " %-*s %-20s %s\n",
- dynamic.offset, dynamic.size/dynamic.entsize,
- w+2, "Tag", "Type", "Name/Value");
- while (dyn < end) {
- unsigned long long tag = elf_long(&dyn), val = elf_long(&dyn);
- char *type = dt_type(tag);
-
- printf(" 0x%0*llx %-20s ", w, tag, *type=='0' ? type : type+1);
- if (*type == 'd') printf("%lld\n", val);
- else if (*type == 'b') printf("%lld (bytes)\n", val);
- else if (*type == 's') printf("%s\n", TT.elf+dynstr.offset+val);
- else if (*type == 'f' || *type == 'F') {
- struct bitname { int bit; char *s; }
- df_names[] = {{0, "ORIGIN"},{1,"SYMBOLIC"},{2,"TEXTREL"},
- {3,"BIND_NOW"},{4,"STATIC_TLS"},{}},
- df_1_names[]={{0,"NOW"},{1,"GLOBAL"},{2,"GROUP"},{3,"NODELETE"},
- {5,"INITFIRST"},{27,"PIE"},{}},
- *names = *type == 'f' ? df_names : df_1_names;
- int mask;
-
- if (*type == 'F') printf("Flags: ");
- for (j=0; names[j].s; j++) {
- if (val & (mask=(1<<names[j].bit))) {
- printf("%s%s", names[j].s, (val &= ~mask) ? " " : "");
+ else if (!dynamic.entsize) printf("Bad dynamic entry size 0!\n");
+ else {
+ printf("Dynamic section at offset 0x%llx contains %lld entries:\n"
+ " %-*s %-20s %s\n",
+ dynamic.offset, dynamic.size/dynamic.entsize,
+ w+2, "Tag", "Type", "Name/Value");
+ while (dyn < end) {
+ unsigned long long tag = elf_long(&dyn), val = elf_long(&dyn);
+ char *type = dt_type(tag);
+
+ printf(" 0x%0*llx %-20s ", w, tag, *type=='0' ? type : type+1);
+ if (*type == 'd') printf("%lld\n", val);
+ else if (*type == 'b') printf("%lld (bytes)\n", val);
+ else if (*type == 's') printf("%s\n", TT.elf+dynstr.offset+val);
+ else if (*type == 'f' || *type == 'F') {
+ struct bitname { int bit; char *s; }
+ df_names[] = {{0, "ORIGIN"},{1,"SYMBOLIC"},{2,"TEXTREL"},
+ {3,"BIND_NOW"},{4,"STATIC_TLS"},{}},
+ df_1_names[]={{0,"NOW"},{1,"GLOBAL"},{2,"GROUP"},{3,"NODELETE"},
+ {5,"INITFIRST"},{27,"PIE"},{}},
+ *names = *type == 'f' ? df_names : df_1_names;
+ int mask;
+
+ if (*type == 'F') printf("Flags: ");
+ for (j=0; names[j].s; j++) {
+ if (val & (mask=(1<<names[j].bit))) {
+ printf("%s%s", names[j].s, (val &= ~mask) ? " " : "");
+ }
}
- }
- if (val) printf("0x%llx", val);
- xputc('\n');
- } else if (*type == 'N' || *type == 'R' || *type == 'S') {
- printf("%s: [%s]\n", *type=='N' ? "Shared library" :
- (*type=='R' ? "Library runpath" : "Library soname"),
- TT.elf+dynstr.offset+val);
- } else if (*type == 'P') {
- type = dt_type(val);
- j = strlen(type);
- if (*type != '0') type += 2, j -= 3;
- printf("%*.*s\n", j, j, type);
- } else printf("0x%llx\n", val);
+ if (val) printf("0x%llx", val);
+ xputc('\n');
+ } else if (*type == 'N' || *type == 'R' || *type == 'S') {
+ char *s = TT.elf+dynstr.offset+val;
+
+ if (dynstr.offset>TT.size || val>TT.size || dynstr.offset>TT.size-val)
+ s = "???";
+ printf("%s: [%s]\n", *type=='N' ? "Shared library" :
+ (*type=='R' ? "Library runpath" : "Library soname"), s);
+ } else if (*type == 'P') {
+ type = dt_type(val);
+ j = strlen(type);
+ if (*type != '0') type += 2, j -= 3;
+ printf("%*.*s\n", j, j, type);
+ } else printf("0x%llx\n", val);
+ }
}
}
@@ -537,7 +572,7 @@ static void scan_elf()
int found = 0;
for (i=0; i<TT.shnum; i++) {
- get_sh(i, &s);
+ if (!get_sh(i, &s)) continue;
if (s.type == 7 /*SHT_NOTE*/) {
printf("\nDisplaying notes found in: %s\n", s.name);
show_notes(s.offset, s.size);
@@ -545,7 +580,7 @@ static void scan_elf()
}
}
for (i=0; !found && i<phnum; i++) {
- get_ph(i, &ph);
+ if (!get_ph(i, &ph)) continue;
if (ph.type == 4 /*PT_NOTE*/) {
printf("\n"
"Displaying notes found at file offset 0x%llx with length 0x%llx:\n",
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 20:14:32 +0000