|
From: <sv...@va...> - 2015-10-29 07:29:11
|
Author: iraisr
Date: Thu Oct 29 07:28:58 2015
New Revision: 15719
Log:
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.
Modified:
trunk/coregrind/m_debuginfo/readelf.c
Modified: trunk/coregrind/m_debuginfo/readelf.c
==============================================================================
--- trunk/coregrind/m_debuginfo/readelf.c (original)
+++ trunk/coregrind/m_debuginfo/readelf.c Thu Oct 29 07:28:58 2015
@@ -1506,6 +1506,11 @@
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);
@@ -1836,13 +1841,88 @@
}
/* 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++) {
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;
- 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 @@
}
}
- 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 @@
/* 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 @@
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 @@
if (svma_ranges) VG_(deleteXA)(svma_ranges);
+# if defined(VGO_solaris)
+ if (rodata_sects != NULL) ML_(dinfo_free)(rodata_sects);
+# endif
+
return res;
} /* out: */
|