Merge 13-data-syms from Jeremy Fitzhardinge:
Fix to the ELF file reader to make sure that each SegInfo includes not
only the text mapped from an ELF file, but also the data and bss. This
allows the data symbols to be extracted. Also adds a new needs boolean
to allow a skin to specify if it needs data symbols. As a nice
side-effect, it removes the "offset" hack: the offset is the mapped
address in the ELF Phdr: it is (mapped_address - phdr_vaddr).
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@1246 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/vg_symtab2.c b/coregrind/vg_symtab2.c
index 08928cd..c536fa3 100644
--- a/coregrind/vg_symtab2.c
+++ b/coregrind/vg_symtab2.c
@@ -117,12 +117,16 @@
*/
UInt offset;
- /* Bounds of PLT and GOT, so that skins can see what section an
- address is in */
+ /* Bounds of data, BSS, PLT and GOT, so that skins can see what
+ section an address is in */
Addr plt_start;
UInt plt_size;
Addr got_start;
UInt got_size;
+ Addr data_start;
+ UInt data_size;
+ Addr bss_start;
+ UInt bss_size;
};
@@ -153,7 +157,7 @@
# define NN 5
/* prevN[0] has the most recent, prevN[NN-1] the least recent */
- static UInt prevN[] = { EMPTY, EMPTY, EMPTY, EMPTY, EMPTY };
+ static UInt prevN[NN] = { EMPTY, EMPTY, EMPTY, EMPTY, EMPTY };
static SegInfo* curr_si = NULL;
Char* new_tab;
@@ -1345,7 +1349,7 @@
/* Read the symbols from the object/exe specified by the SegInfo into
the tables within the supplied SegInfo. */
static
-void vg_read_lib_symbols ( SegInfo* si )
+Bool vg_read_lib_symbols ( SegInfo* si )
{
Elf32_Ehdr* ehdr; /* The ELF header */
Elf32_Shdr* shdr; /* The section table */
@@ -1374,14 +1378,14 @@
i = VG_(stat)(si->filename, &stat_buf);
if (i != 0) {
vg_symerr("Can't stat .so/.exe (to determine its size)?!");
- return;
+ return False;
}
n_oimage = stat_buf.st_size;
fd = VG_(open)(si->filename, VKI_O_RDONLY, 0);
if (fd == -1) {
vg_symerr("Can't open .so/.exe to read symbols?!");
- return;
+ return False;
}
oimage = (Addr)VG_(mmap)( NULL, n_oimage,
@@ -1390,7 +1394,7 @@
VG_(message)(Vg_UserMsg,
"mmap failed on %s", si->filename );
VG_(close)(fd);
- return;
+ return False;
}
VG_(close)(fd);
@@ -1414,12 +1418,81 @@
ok &= (ehdr->e_version == EV_CURRENT);
ok &= (ehdr->e_shstrndx != SHN_UNDEF);
ok &= (ehdr->e_shoff != 0 && ehdr->e_shnum != 0);
+ ok &= (ehdr->e_phoff != 0 && ehdr->e_phnum != 0);
}
if (!ok) {
vg_symerr("Invalid ELF header, or missing stringtab/sectiontab.");
VG_(munmap) ( (void*)oimage, n_oimage );
- return;
+ return False;
+ }
+
+ /* Walk the LOAD headers in the phdr and update the SegInfo to
+ include them all, so that this segment also contains data and
+ bss memory. Also computes correct symbol offset value for this
+ ELF file. */
+ if (ehdr->e_phoff + ehdr->e_phnum*sizeof(Elf32_Phdr) > n_oimage) {
+ vg_symerr("ELF program header is beyond image end?!");
+ VG_(munmap) ( (void*)oimage, n_oimage );
+ return False;
+ }
+ {
+ Bool offset_set = False;
+ Elf32_Addr prev_addr = 0;
+
+ si->offset = 0;
+
+ for(i = 0; i < ehdr->e_phnum; i++) {
+ Elf32_Phdr *o_phdr;
+ Elf32_Addr mapped, mapped_end;
+
+ o_phdr = &((Elf32_Phdr *)(oimage + ehdr->e_phoff))[i];
+
+ if (o_phdr->p_type != PT_LOAD)
+ continue;
+
+ if (!offset_set) {
+ offset_set = True;
+ si->offset = si->start - o_phdr->p_vaddr;
+ }
+
+ if (o_phdr->p_vaddr < prev_addr) {
+ vg_symerr("ELF Phdrs are out of order!?");
+ VG_(munmap) ( (void*)oimage, n_oimage );
+ return False;
+ }
+ prev_addr = o_phdr->p_vaddr;
+
+ mapped = o_phdr->p_vaddr + si->offset;
+ mapped_end = mapped + o_phdr->p_memsz;
+
+ if (si->data_start == 0 &&
+ (o_phdr->p_flags & (PF_R|PF_W|PF_X)) == (PF_R|PF_W)) {
+ si->data_start = mapped;
+ si->data_size = o_phdr->p_filesz;
+ si->bss_start = mapped + o_phdr->p_filesz;
+ if (o_phdr->p_memsz > o_phdr->p_filesz)
+ si->bss_size = o_phdr->p_memsz - o_phdr->p_filesz;
+ else
+ si->bss_size = 0;
+ }
+
+ mapped = mapped & ~(VKI_BYTES_PER_PAGE-1);
+ mapped_end = (mapped_end + VKI_BYTES_PER_PAGE - 1) & ~(VKI_BYTES_PER_PAGE-1);
+
+ if (VG_(needs).data_syms &&
+ (mapped >= si->start && mapped <= (si->start+si->size)) &&
+ (mapped_end > (si->start+si->size))) {
+ UInt newsz = mapped_end - si->start;
+ if (newsz > si->size) {
+ if (0)
+ VG_(printf)("extending mapping %p..%p %d -> ..%p %d\n",
+ si->start, si->start+si->size, si->size,
+ si->start+newsz, newsz);
+ si->size = newsz;
+ }
+ }
+ }
}
if (VG_(clo_trace_symtab))
@@ -1430,7 +1503,7 @@
if (ehdr->e_shoff + ehdr->e_shnum*sizeof(Elf32_Shdr) > n_oimage) {
vg_symerr("ELF section header is beyond image end?!");
VG_(munmap) ( (void*)oimage, n_oimage );
- return;
+ return False;
}
shdr = (Elf32_Shdr*)(oimage + ehdr->e_shoff);
@@ -1519,17 +1592,18 @@
/* Perhaps should start at i = 1; ELF docs suggest that entry
0 always denotes `unknown symbol'. */
for (i = 1; i < o_symtab_sz/sizeof(Elf32_Sym); i++){
-# if 0
- VG_(printf)("raw symbol: ");
- switch (ELF32_ST_BIND(o_symtab[i].st_info)) {
+# if 1
+ if (VG_(clo_trace_symtab)) {
+ VG_(printf)("raw symbol: ");
+ switch (ELF32_ST_BIND(o_symtab[i].st_info)) {
case STB_LOCAL: VG_(printf)("LOC "); break;
case STB_GLOBAL: VG_(printf)("GLO "); break;
case STB_WEAK: VG_(printf)("WEA "); break;
case STB_LOPROC: VG_(printf)("lop "); break;
case STB_HIPROC: VG_(printf)("hip "); break;
default: VG_(printf)("??? "); break;
- }
- switch (ELF32_ST_TYPE(o_symtab[i].st_info)) {
+ }
+ switch (ELF32_ST_TYPE(o_symtab[i].st_info)) {
case STT_NOTYPE: VG_(printf)("NOT "); break;
case STT_OBJECT: VG_(printf)("OBJ "); break;
case STT_FUNC: VG_(printf)("FUN "); break;
@@ -1538,14 +1612,15 @@
case STT_LOPROC: VG_(printf)("lop "); break;
case STT_HIPROC: VG_(printf)("hip "); break;
default: VG_(printf)("??? "); break;
- }
- VG_(printf)(
- ": value %p, size %d, name %s\n",
- si->offset+(UChar*)o_symtab[i].st_value,
- o_symtab[i].st_size,
- o_symtab[i].st_name
- ? ((Char*)o_strtab+o_symtab[i].st_name)
- : (Char*)"NONAME");
+ }
+ VG_(printf)(
+ ": value %p, size %d, name %s\n",
+ si->offset+(UChar*)o_symtab[i].st_value,
+ o_symtab[i].st_size,
+ o_symtab[i].st_name
+ ? ((Char*)o_strtab+o_symtab[i].st_name)
+ : (Char*)"NONAME");
+ }
# endif
/* Figure out if we're interested in the symbol.
@@ -1556,8 +1631,8 @@
ELF32_ST_BIND(o_symtab[i].st_info) == STB_LOCAL /* ||
ELF32_ST_BIND(o_symtab[i].st_info) == STB_WEAK */)
&&
- (ELF32_ST_TYPE(o_symtab[i].st_info) == STT_FUNC /*||
- ELF32_ST_TYPE(o_symtab[i].st_info) == STT_OBJECT*/)
+ (ELF32_ST_TYPE(o_symtab[i].st_info) == STT_FUNC ||
+ (VG_(needs).data_syms && ELF32_ST_TYPE(o_symtab[i].st_info) == STT_OBJECT))
);
/* Secondly, if it's apparently in a GOT or PLT, it's really
@@ -1641,8 +1716,8 @@
vg_assert(nmoff >= 0
/* && 0==VG_(strcmp)(t0,&vg_strtab[nmoff]) */ );
vg_assert( (Int)o_symtab[i].st_value >= 0);
- /* VG_(printf)("%p + %d: %s\n", si->addr,
- (Int)o_symtab[i].st_value, t0 ); */
+ /* VG_(printf)("%p + %d: %p %s\n", si->start,
+ (Int)o_symtab[i].st_value, sym_addr, t0 ); */
sym.addr = sym_addr;
sym.size = o_symtab[i].st_size;
sym.nmoff = nmoff;
@@ -1680,7 +1755,7 @@
if ((stab == NULL || stabstr == NULL) && dwarf2 == NULL) {
vg_symerr(" object doesn't have any debug info");
VG_(munmap) ( (void*)oimage, n_oimage );
- return;
+ return False;
}
if ( stab_sz + (UChar*)stab > n_oimage + (UChar*)oimage
@@ -1688,13 +1763,13 @@
> n_oimage + (UChar*)oimage ) {
vg_symerr(" ELF (stabs) debug data is beyond image end?!");
VG_(munmap) ( (void*)oimage, n_oimage );
- return;
+ return False;
}
if ( dwarf2_sz + (UChar*)dwarf2 > n_oimage + (UChar*)oimage ) {
vg_symerr(" ELF (dwarf2) debug data is beyond image end?!");
VG_(munmap) ( (void*)oimage, n_oimage );
- return;
+ return False;
}
/* Looks plausible. Go on and read debug data. */
@@ -1708,6 +1783,8 @@
/* Last, but not least, heave the oimage back overboard. */
VG_(munmap) ( (void*)oimage, n_oimage );
+
+ return True;
}
@@ -1741,6 +1818,8 @@
return;
if (0 == VG_(strcmp)(filename, "/dev/zero"))
return;
+ if (foffset != 0)
+ return;
/* Perhaps we already have this one? If so, skip. */
for (si = segInfo; si != NULL; si = si->next) {
@@ -1760,9 +1839,8 @@
/* Get the record initialised right. */
si = VG_(arena_malloc)(VG_AR_SYMTAB, sizeof(SegInfo));
- si->next = segInfo;
- segInfo = si;
+ VG_(memset)(si, 0, sizeof(*si));
si->start = start;
si->size = size;
si->foffset = foffset;
@@ -1776,13 +1854,23 @@
si->strtab = NULL;
si->strtab_size = si->strtab_used = 0;
- /* Kludge ... */
- si->offset = si->start==VG_ASSUMED_EXE_BASE ? 0 : si->start;
-
/* And actually fill it up. */
- vg_read_lib_symbols ( si );
- canonicaliseSymtab ( si );
- canonicaliseLoctab ( si );
+ if (!vg_read_lib_symbols ( si ) && 0) {
+ /* XXX this interacts badly with the prevN optimization in
+ addStr(). Since this frees the si, the si pointer value can
+ be recycled, which confuses the curr_si == si test. For now,
+ this code is disabled, and everything is included in the
+ segment list, even if it is a bad ELF file. Ironically,
+ running this under valgrind itself hides the problem, because
+ it doesn't recycle pointers... */
+ freeSegInfo( si );
+ } else {
+ si->next = segInfo;
+ segInfo = si;
+
+ canonicaliseSymtab ( si );
+ canonicaliseLoctab ( si );
+ }
}
@@ -2190,13 +2278,19 @@
for(seg = segInfo; seg != NULL; seg = seg->next) {
if (a >= seg->start && a < (seg->start + seg->size)) {
if (0)
- VG_(printf)("addr=%p seg=%p %s got=%p %d plt=%p %d\n",
+ VG_(printf)("addr=%p seg=%p %s got=%p %d plt=%p %d data=%p %d bss=%p %d\n",
a, seg, seg->filename,
seg->got_start, seg->got_size,
- seg->plt_start, seg->plt_size);
+ seg->plt_start, seg->plt_size,
+ seg->data_start, seg->data_size,
+ seg->bss_start, seg->bss_size);
ret = Vg_SectText;
- if (a >= seg->plt_start && a < (seg->plt_start + seg->plt_size))
+ if (a >= seg->data_start && a < (seg->data_start + seg->data_size))
+ ret = Vg_SectData;
+ else if (a >= seg->bss_start && a < (seg->bss_start + seg->bss_size))
+ ret = Vg_SectBSS;
+ else if (a >= seg->plt_start && a < (seg->plt_start + seg->plt_size))
ret = Vg_SectPLT;
else if (a >= seg->got_start && a < (seg->got_start + seg->got_size))
ret = Vg_SectGOT;