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authorRob Landley <rob@landley.net>2021-05-15 13:56:19 -0500
committerRob Landley <rob@landley.net>2021-05-15 13:56:19 -0500
commit36dd3b2d27ac7a89754dbdbed6b81f3662e4dafb (patch)
tree918465da7bae008cef4d8f6fc2214c5969cdbfc3 /toys/pending
parent267a1a572d8780c11b63fb8640e4c3752ce7f1a1 (diff)
downloadtoybox-36dd3b2d27ac7a89754dbdbed6b81f3662e4dafb.tar.gz
Cleanup readelf.
Diffstat (limited to 'toys/pending')
-rw-r--r--toys/pending/readelf.c193
1 files changed, 85 insertions, 108 deletions
diff --git a/toys/pending/readelf.c b/toys/pending/readelf.c
index e6e1623f..75726ecb 100644
--- a/toys/pending/readelf.c
+++ b/toys/pending/readelf.c
@@ -54,8 +54,12 @@ struct ph {
static long long elf_get(char **p, int len)
{
- long long result = ((TT.endian == 2) ? peek_be : peek_le)(*p, len);
+ long long result;
+ if (*p+len-TT.elf>TT.size)
+ perror_exit("Access off end: %ld[%d] of %lld\n", *p-TT.elf, len, TT.size);
+
+ result = ((TT.endian == 2) ? peek_be : peek_le)(*p, len);
*p += len;
return result;
}
@@ -118,17 +122,15 @@ static int get_sh(unsigned i, struct sh *s)
static int find_section(char *spec, struct sh *s)
{
char *end;
- int i;
+ unsigned i;
// Valid section number?
- errno = 0;
- i = strtoul(spec, &end, 0);
- if (!errno && !*end && i < TT.shnum) return get_sh(i, s);
+ i = estrtol(spec, &end, 0);
+ if (!errno && !*end && i<TT.shnum) return get_sh(i, s);
// Search the section names.
- for (i=0; i<TT.shnum; i++) {
+ for (i=0; i<TT.shnum; i++)
if (get_sh(i, s) && !strcmp(s->name, spec)) return 1;
- }
error_msg("%s: no section '%s", TT.f, spec);
return 0;
@@ -243,17 +245,16 @@ static void show_symbols(struct sh *table, struct sh *strtab)
char *symtab = TT.elf+table->offset, *ndx;
int numsym = table->size/(TT.bits ? 24 : 16), i;
- if (numsym == 0) return;
+ if (!numsym) return;
xputc('\n');
printf("Symbol table '%s' contains %d entries:\n"
" Num: %*s Size Type Bind Vis Ndx Name\n",
table->name, numsym, 5+8*TT.bits, "Value");
for (i=0; i<numsym; i++) {
- unsigned st_name = elf_int(&symtab), st_value, st_shndx;
- unsigned char st_info, st_other;
+ unsigned st_name = elf_int(&symtab), st_value, st_shndx, st_info, st_other;
unsigned long st_size;
- char *name;
+ char *name, buf[16];
// The various fields were moved around for 64-bit.
if (TT.bits) {
@@ -270,12 +271,13 @@ static void show_symbols(struct sh *table, struct sh *strtab)
st_shndx = elf_short(&symtab);
}
+ // TODO: why do we trust name to be null terminated?
name = TT.elf + strtab->offset + st_name;
if (name >= TT.elf+TT.size) name = "???";
if (!st_shndx) ndx = "UND";
else if (st_shndx==0xfff1) ndx = "ABS";
- else sprintf(ndx = toybuf, "%d", st_shndx);
+ else sprintf(ndx = buf, "%d", st_shndx);
// TODO: look up and show any symbol versions with @ or @@.
@@ -285,10 +287,11 @@ static void show_symbols(struct sh *table, struct sh *strtab)
}
}
-static int notematch(int namesz, char **p, char *expected, int len)
+static int notematch(int namesz, char **p, char *expected)
{
- if (namesz != len || memcmp(*p, expected, namesz)) return 0;
+ if (namesz!=strlen(expected)+1 || strcmp(*p, expected)) return 0;
*p += namesz;
+
return 1;
}
@@ -298,44 +301,46 @@ static void show_notes(unsigned long offset, unsigned long size)
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");
+ printf(" %-20s%11s\tDescription\n", "Owner", "Data size");
while (note < TT.elf+offset+size) {
char *p = note, *desc;
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;
- }
+ if (namesz > size || descsz > size)
+ return error_msg("%s: bad note @%lu", TT.f, offset);
printf(" %-20.*s 0x%08x\t", namesz, p, descsz);
- if (notematch(namesz, &p, "GNU", 4)) {
+ if (notematch(namesz, &p, "GNU")) {
if (type == 1) {
printf("NT_GNU_ABI_TAG\tOS: %s, ABI: %u.%u.%u",
!elf_int(&p)?"Linux":"?", elf_int(&p), elf_int(&p), elf_int(&p)), j=1;
} else if (type == 3) {
+// TODO should this set j=1?
printf("NT_GNU_BUILD_ID\t");
for (;j<descsz;j++) printf("%02x", *p++);
} else if (type == 4) {
printf("NT_GNU_GOLD_VERSION\t%.*s", descsz, p), j=1;
} else p -= 4;
- } else if (notematch(namesz, &p, "Android", 8)) {
+ } else if (notematch(namesz, &p, "Android")) {
if (type == 1) {
printf("NT_VERSION\tAPI level %u", elf_int(&p)), j=1;
if (descsz>=132) printf(", NDK %.64s (%.64s)", p, p+64);
} else p -= 8;
- } else if (notematch(namesz, &p, "CORE", 5)) {
+ } else if (notematch(namesz, &p, "CORE")) {
if (*(desc = nt_type_core(type)) != '0') printf("%s", desc), j=1;
- } else if (notematch(namesz, &p, "LINUX", 6)) {
+// TODO else p -= 5?
+ } else if (notematch(namesz, &p, "LINUX")) {
if (*(desc = nt_type_linux(type)) != '0') printf("%s", desc), j=1;
+// TODO else p -= 6?
}
// If we didn't do custom output above, show a hex dump.
if (!j) {
printf("0x%x\t", type);
- for (;j<descsz;j++) printf("%c%02x",!j?'\t':' ', *p++/*note[16+j]*/);
+ for (;j<descsz;j++) printf("%c%02x", j ? ' ' : '\t', *p++/*note[16+j]*/);
}
xputc('\n');
note += 3*4 + ((namesz+3)&~3) + ((descsz+3)&~3);
@@ -350,17 +355,13 @@ static void scan_elf()
char *hdr = TT.elf;
int type, machine, version, flags, entry, ehsize, phnum, shstrndx, i, j, w;
- if (TT.size < 45 || memcmp(hdr, "\177ELF", 4)) {
- error_msg("%s: not ELF", TT.f);
- return;
- }
+ if (TT.size < 45 || memcmp(hdr, "\177ELF", 4))
+ return error_msg("%s: not ELF", TT.f);
TT.bits = hdr[4] - 1;
TT.endian = hdr[5];
- if (TT.bits<0 || TT.bits>1 || TT.endian<1 || TT.endian>2 || hdr[6]!=1) {
- error_msg("%s: bad ELF", TT.f);
- return;
- }
+ if (TT.bits<0 || TT.bits>1 || TT.endian<1 || TT.endian>2 || hdr[6]!=1)
+ return error_msg("%s: bad ELF", TT.f);
hdr += 16; // EI_NIDENT
type = elf_short(&hdr);
@@ -382,7 +383,7 @@ static void scan_elf()
if (FLAG(h)) {
printf("ELF Header:\n");
printf(" Magic: ");
- for (i=0; i<16; i++) printf("%02x%c", TT.elf[i], i==15?'\n':' ');
+ for (i=0; i<16; i++) printf("%02x%c", TT.elf[i], (i==15) ? '\n' : ' ');
printf(" Class: ELF%d\n", TT.bits?64:32);
printf(" Data: 2's complement, %s endian\n",
(TT.endian==2)?"big":"little");
@@ -405,24 +406,16 @@ 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;
- }
+ if (TT.phoff > TT.size) return error_msg("%s: bad phoff", TT.f);
+ if (TT.shoff > TT.size) return error_msg("%s: bad shoff", TT.f);
// 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;
- }
+ if (shstrndx) {
+ if (!get_sh(shstrndx, &shstr) || shstr.type != 3 /*SHT_STRTAB*/)
+ return error_msg("%s: bad shstrndx", TT.f);
TT.shstrtab = TT.elf+shstr.offset;
TT.shstrtabsz = shstr.size;
}
@@ -431,12 +424,10 @@ static void scan_elf()
if (FLAG(S)) {
if (!TT.shnum) printf("\nThere are no sections in this file.\n");
else {
- if (!FLAG(h)) {
+ if (!FLAG(h))
printf("There are %d section headers, starting at offset %#llx:\n",
TT.shnum, TT.shoff);
- }
- printf("\n"
- "Section Headers:\n"
+ printf("\nSection Headers:\n"
" [Nr] %-17s %-15s %-*s %-6s %-6s ES Flg Lk Inf Al\n",
"Name", "Type", w, "Address", "Off", "Size");
}
@@ -456,48 +447,42 @@ static void scan_elf()
if (FLAG(S)) {
char sh_flags[12] = {}, *p = sh_flags;
- for (j=0; j<12; j++) if (s.flags&(1<<j)) *p++="WAXxMSILOTC"[j];
+ for (j=0; j<12; j++) if (s.flags&(1<<j)) *p++ = "WAXxMSILOTC"[j];
printf(" [%2d] %-17s %-15s %0*llx %06llx %06llx %02llx %3s %2d %2d %2lld\n",
i, s.name, sh_type(s.type), w, s.addr, s.offset, s.size,
s.entsize, sh_flags, s.link, s.info, s.addralign);
}
}
- if (FLAG(S) && TT.shnum) {
- printf("Key:\n"
- " (W)rite, (A)lloc, e(X)ecute, (M)erge, (S)trings, (I)nfo\n"
+ if (FLAG(S) && TT.shnum)
+ printf("Key:\n (W)rite, (A)lloc, e(X)ecute, (M)erge, (S)trings, (I)nfo\n"
" (L)ink order, (O)S, (G)roup, (T)LS, (C)ompressed, x=unknown\n");
- }
if (FLAG(l)) {
xputc('\n');
if (!phnum) printf("There are no program headers in this file.\n");
else {
- if (!FLAG(h)) {
- printf("Elf file type is %s\n"
- "Entry point %#x\n"
- "There are %d program headers, starting at offset %lld\n"
- "\n",
- et_type(type), entry, phnum, TT.phoff);
- }
+ if (!FLAG(h))
+ printf("Elf file type is %s\nEntry point %#x\n"
+ "There are %d program headers, starting at offset %lld\n\n",
+ et_type(type), entry, phnum, TT.phoff);
printf("Program Headers:\n"
" %-14s %-8s %-*s %-*s %-7s %-7s Flg Align\n", "Type",
"Offset", w, "VirtAddr", w, "PhysAddr", "FileSiz", "MemSiz");
- for (i=0; i<phnum; i++) {
+ for (i = 0; i<phnum; i++) {
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);
+ 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<TT.size &&
ph.offset<TT.size && ph.filesz - 1 < TT.size - ph.offset) {
+// TODO: ph.filesz of 0 prints unlimited length string
printf(" [Requesting program interpreter: %*s]\n",
(int) ph.filesz-1, TT.elf+ph.offset);
}
}
- printf("\n"
- " Section to Segment mapping:\n"
- " Segment Sections...\n");
+ printf("\n Section to Segment mapping:\n Segment Sections...\n");
for (i=0; i<phnum; i++) {
if (!get_ph(i, &ph)) continue;
printf(" %02d ", i);
@@ -522,16 +507,16 @@ static void scan_elf()
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,
+ " %-*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);
+ printf(" 0x%0*llx %-20s ", w, tag, type+(*type!='0'));
if (*type == 'd') printf("%lld\n", val);
else if (*type == 'b') printf("%lld (bytes)\n", val);
+// TODO: trusting this %s to be null terminated
else if (*type == 's') printf("%s\n", TT.elf+dynstr.offset+val);
else if (*type == 'f' || *type == 'F') {
struct bitname { int bit; char *s; }
@@ -543,11 +528,9 @@ static void scan_elf()
int mask;
if (*type == 'F') printf("Flags: ");
- for (j=0; names[j].s; j++) {
- if (val & (mask=(1<<names[j].bit))) {
+ 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') {
@@ -558,8 +541,7 @@ static void scan_elf()
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);
+ j = strlen(type = dt_type(val));
if (*type != '0') type += 2, j -= 3;
printf("%*.*s\n", j, j, type);
} else printf("0x%llx\n", val);
@@ -592,44 +574,39 @@ static void scan_elf()
}
}
- if (FLAG(x)) {
- if (find_section(TT.x, &s)) {
- char *p = TT.elf+s.offset;
- long offset = 0;
+ if (FLAG(x) && find_section(TT.x, &s)) {
+ char *p = TT.elf+s.offset;
+ long offset = 0;
- printf("\nHex dump of section '%s':\n", s.name);
- while (offset < s.size) {
- int space = 2*16 + 16/4;
+ printf("\nHex dump of section '%s':\n", s.name);
+ while (offset < s.size) {
+ int space = 2*16 + 16/4;
- printf(" 0x%08lx ", offset);
- for (i=0; i<16 && offset < s.size; offset++) {
- space -= printf("%02x%s", *p++, ++i%4 ? "" : " ");
- }
- printf("%*s", space, "");
- for (p-=i; i; i--, p++) putchar(*p>=' ' && *p<='~' ? *p : '.');
- xputc('\n');
- }
- printf("\n");
+ printf(" 0x%08lx ", offset);
+ for (i=0; i<16 && offset < s.size; offset++)
+ space -= printf("%02x%s", *p++, " "+!!(++i%4));
+ printf("%*s", space, "");
+ for (p -= i; i; i--, p++) putchar((*p>=' ' && *p<='~') ? *p : '.');
+ xputc('\n');
}
+ xputc('\n');
}
- if (FLAG(p)) {
- if (find_section(TT.p, &s)) {
- char *begin = TT.elf+s.offset, *end = begin + s.size, *p = begin;
- int any = 0;
+ if (FLAG(p) && find_section(TT.p, &s)) {
+ char *begin = TT.elf+s.offset, *end = begin + s.size, *p = begin;
+ int any = 0;
- printf("\nString dump of section '%s':\n", s.name);
- for (; p < end; p++) {
- if (isprint(*p)) {
- printf(" [%6tx] ", p-begin);
- while (p < end && isprint(*p)) putchar(*p++);
- xputc('\n');
- any=1;
- }
+ printf("\nString dump of section '%s':\n", s.name);
+ for (; p < end; p++) {
+ if (isprint(*p)) {
+ printf(" [%6tx] ", p-begin);
+ while (p < end && isprint(*p)) putchar(*p++);
+ xputc('\n');
+ any=1;
}
- if (!any) printf(" No strings found in this section.\n");
- printf("\n");
}
+ if (!any) printf(" No strings found in this section.\n");
+ xputc('\n');
}
}
@@ -653,7 +630,7 @@ void readelf_main(void)
else if (!sb.st_size) error_msg("%s: empty", TT.f);
else if (!S_ISREG(sb.st_mode)) error_msg("%s: not a regular file",TT.f);
else {
- TT.elf = xmmap(NULL, TT.size=sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
+ TT.elf = xmmap(0, TT.size=sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
scan_elf();
munmap(TT.elf, TT.size);
}