ELF debug info reader was confused with multiple .rodata sections on Solaris

The ELF debug info reader on Solaris now performs a quick pre-scan of section
headers for .rodata sections. If there are multiple .rodata sections
present then symbols from .symtab are scanned which section they point to.
The "true" .rodata section is thus determined.
Fixes BZ#353802.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15719
This commit is contained in:
Ivo Raisr 2015-10-29 07:28:58 +00:00
parent e7be5069c3
commit 1cc06c7e14

View File

@ -1506,6 +1506,11 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
XArray* /* of RangeAndBias */ svma_ranges = NULL;
# if defined(VGO_solaris)
Word *rodata_sects = NULL;
Word rodata_shndx = -1;
# endif /* VGO_solaris */
vg_assert(di);
vg_assert(di->fsm.have_rx_map == True);
vg_assert(di->fsm.have_rw_map == True);
@ -1835,6 +1840,81 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
reg->svma_base, reg->svma_limit - 1, (UWord)reg->bias );
}
/* TOPLEVEL */
# if defined(VGO_solaris)
/* Quick pre-scan of sections headers. Check if multiple .rodata sections
are present. See https://bugs.kde.org/show_bug.cgi?id=353802 */
rodata_sects = ML_(dinfo_zalloc)("di.redi_name.1",
shdr_mnent * sizeof(Word));
Word rodata_nsects = 0;
Word symtab_shndx = -1;
DiOffT symtab_sz = DiOffT_INVALID;
DiOffT symtab_ioff = DiOffT_INVALID;
for (i = 0; i < shdr_mnent; i++) {
ElfXX_Shdr a_shdr;
ML_(img_get)(&a_shdr, mimg,
INDEX_BIS(shdr_mioff, i, shdr_ment_szB), sizeof(a_shdr));
DiOffT name_mioff = shdr_strtab_mioff + a_shdr.sh_name;
if (ML_(img_strcmp_c)(mimg, name_mioff, ".rodata") == 0) {
rodata_sects[i] = True;
rodata_nsects += 1;
} else if (ML_(img_strcmp_c)(mimg, name_mioff, ".symtab") == 0) {
symtab_shndx = i;
symtab_sz = a_shdr.sh_size;
symtab_ioff = a_shdr.sh_offset;
}
}
if ((rodata_nsects > 1) && (symtab_shndx != -1)) {
TRACE_SYMTAB("Multiple (%ld) .rodata sections present.\n", rodata_nsects);
/* Multiple .rodata sections present. Which one the symbols point to? */
for (i = 1; i < (Word) (symtab_sz/sizeof(ElfXX_Sym)); i++) {
ElfXX_Sym sym;
ML_(img_get)(&sym, mimg,
symtab_ioff + i * sizeof(ElfXX_Sym), sizeof(sym));
/* Consider only object symbols with size > 0. */
if ((sym.st_size > 0) && (ELFXX_ST_TYPE(sym.st_info) == STT_OBJECT)) {
HChar buf[100]; // large enough
if (sym.st_shndx >= shdr_mnent) {
VG_(snprintf)(buf, sizeof(buf), "Symbol %ld points to a "
"non-existent section %d.\n", i, sym.st_shndx);
ML_(symerr)(di, True, buf);
goto out;
}
if (rodata_sects[sym.st_shndx] == True) {
if (rodata_shndx == -1)
rodata_shndx = sym.st_shndx;
if (rodata_shndx != sym.st_shndx) {
VG_(snprintf)(buf, sizeof(buf), "Object symbols point to "
"multiple .rodata sections (%lu and %d). "
"Giving up.\n", rodata_shndx, sym.st_shndx);
ML_(symerr)(di, True, buf);
goto out;
}
}
}
}
}
if (rodata_shndx == -1) {
if (rodata_nsects >= 1) {
for (i = 0; i < shdr_mnent; i++) {
if (rodata_sects[i] == True)
rodata_shndx = i;
}
}
if (rodata_nsects > 1)
TRACE_SYMTAB("Symbols do not point to any .rodata section. Section "
"#%ld was chosen.\n", rodata_shndx);
} else {
TRACE_SYMTAB("Symbols point only to .rodata section #%ld. Good.\n",
rodata_shndx);
}
# endif /* VGO_solaris */
/* TOPLEVEL */
/* Iterate over section headers */
for (i = 0; i < shdr_mnent; i++) {
@ -1842,7 +1922,7 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
ML_(img_get)(&a_shdr, mimg,
INDEX_BIS(shdr_mioff, i, shdr_ment_szB), sizeof(a_shdr));
DiOffT name_mioff = shdr_strtab_mioff + a_shdr.sh_name;
HChar* name = ML_(img_strdup)(mimg, "di.redi_name.1", name_mioff);
HChar* name = ML_(img_strdup)(mimg, "di.redi_name.2", name_mioff);
Addr svma = a_shdr.sh_addr;
OffT foff = a_shdr.sh_offset;
UWord size = a_shdr.sh_size; /* Do not change this to be signed. */
@ -1867,10 +1947,10 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
}
}
TRACE_SYMTAB(" [sec %2ld] %s %s al%2u foff %6ld .. %6lu "
TRACE_SYMTAB(" [sec %2ld] %s %s al%4u foff %6ld .. %6lu "
" svma %p name \"%s\"\n",
i, inrx ? "rx" : " ", inrw ? "rw" : " ", alyn,
foff, foff+size-1, (void*)svma, name);
foff, (size == 0) ? foff : foff+size-1, (void *) svma, name);
/* Check for sane-sized segments. SHT_NOBITS sections have zero
size in the file and their offsets are just conceptual. */
@ -1977,7 +2057,11 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
/* Accept .rodata where mapped as rx (data), even if zero-sized */
if (0 == VG_(strcmp)(name, ".rodata")) {
if (inrx && !di->rodata_present) {
if (inrx && !di->rodata_present
# if defined(VGO_solaris)
&& i == rodata_shndx
# endif
) {
di->rodata_present = True;
di->rodata_svma = svma;
di->rodata_avma = svma + inrx->bias;
@ -1994,6 +2078,11 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
di->rodata_avma + di->rodata_size - 1);
TRACE_SYMTAB("acquiring .rodata bias = %#lx\n",
(UWord)di->rodata_bias);
# if defined(VGO_solaris)
} else if (i != rodata_shndx) {
/* Skip this section. It is of no use to us.
See https://bugs.kde.org/show_bug.cgi?id=353802 */
# endif
} else {
BAD(".rodata");
}
@ -3030,6 +3119,10 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
if (svma_ranges) VG_(deleteXA)(svma_ranges);
# if defined(VGO_solaris)
if (rodata_sects != NULL) ML_(dinfo_free)(rodata_sects);
# endif
return res;
} /* out: */