Cope with prelink splitting the bss section of an ELF file into separate

dynbss and bss sections by merging them back together again.

This means that (a) we will find variables in the bss and (b) we won't
assert when there is a debuginfo file present where the bss is still
in one piece.

Patch from Jakub Jelinek, closes #217084.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10963

diff --git a/coregrind/m_debuginfo/readelf.c b/coregrind/m_debuginfo/readelf.c
index df7bcb576a3d7a4ee8b09525f3abefbca45779bd..52d1b698218902546e036cf965fc4ab81c9235c9 100644 (file)
--- a/coregrind/m_debuginfo/readelf.c
+++ b/coregrind/m_debuginfo/readelf.c
@@ -1062,6 +1062,8 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
    Bool          res, ok;
    SysRes        fd, sres;
    Word          i;
+   Bool          dynbss_present = False;
+   Bool          sdynbss_present = False;
 
    /* Image addresses for the ELF file we're working with. */
    Addr          oimage   = 0;
@@ -1476,8 +1478,40 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
          }
       }
 
+      if (0 == VG_(strcmp)(name, ".dynbss")) {
+         if (inrw && size > 0 && !di->bss_present) {
+            dynbss_present = True;
+            di->bss_present = True;
+            di->bss_svma = svma;
+            di->bss_avma = svma + rw_bias;
+            di->bss_size = size;
+            di->bss_bias = rw_bias;
+            di->bss_debug_svma = svma;
+            di->bss_debug_bias = rw_bias;
+            TRACE_SYMTAB("acquiring .dynbss svma = %#lx .. %#lx\n",
+                         di->bss_svma,
+                         di->bss_svma + di->bss_size - 1);
+            TRACE_SYMTAB("acquiring .dynbss avma = %#lx .. %#lx\n",
+                         di->bss_avma,
+                         di->bss_avma + di->bss_size - 1);
+            TRACE_SYMTAB("acquiring .dynbss bias = %#lx\n", di->bss_bias);
+         }
+      }
+
       /* Accept .bss where mapped as rw (data), even if zero-sized */
       if (0 == VG_(strcmp)(name, ".bss")) {
+         if (inrw && size > 0 && dynbss_present) {
+            vg_assert(di->bss_present);
+            dynbss_present = False;
+            vg_assert(di->bss_svma + di->bss_size == svma);
+            di->bss_size += size;
+            TRACE_SYMTAB("acquiring .bss svma = %#lx .. %#lx\n",
+                         svma, svma + size - 1);
+            TRACE_SYMTAB("acquiring .bss avma = %#lx .. %#lx\n",
+                         svma + rw_bias, svma + rw_bias + size - 1);
+            TRACE_SYMTAB("acquiring .bss bias = %#lx\n", di->bss_bias);
+         } else
+
          if (inrw && size >= 0 && !di->bss_present) {
             di->bss_present = True;
             di->bss_svma = svma;
@@ -1529,8 +1563,40 @@ Bool ML_(read_elf_debug_info) ( struct _DebugInfo* di )
          }
       }
 
+      if (0 == VG_(strcmp)(name, ".sdynbss")) {
+         if (inrw && size >= 0 && !di->sbss_present) {
+            sdynbss_present = True;
+            di->sbss_present = True;
+            di->sbss_svma = svma;
+            di->sbss_avma = svma + rw_bias;
+            di->sbss_size = size;
+            di->sbss_bias = rw_bias;
+            di->sbss_debug_svma = svma;
+            di->sbss_debug_bias = rw_bias;
+            TRACE_SYMTAB("acquiring .sdynbss svma = %#lx .. %#lx\n",
+                         di->sbss_svma,
+                         di->sbss_svma + di->sbss_size - 1);
+            TRACE_SYMTAB("acquiring .sdynbss avma = %#lx .. %#lx\n",
+                         di->sbss_avma,
+                         di->sbss_avma + di->sbss_size - 1);
+            TRACE_SYMTAB("acquiring .sdynbss bias = %#lx\n", di->sbss_bias);
+         }
+      }
+
       /* Accept .sbss where mapped as rw (data) */
       if (0 == VG_(strcmp)(name, ".sbss")) {
+         if (inrw && size > 0 && sdynbss_present) {
+            vg_assert(di->sbss_present);
+            sdynbss_present = False;
+            vg_assert(di->sbss_svma + di->sbss_size == svma);
+            di->sbss_size += size;
+            TRACE_SYMTAB("acquiring .sbss svma = %#lx .. %#lx\n",
+                         svma, svma + size - 1);
+            TRACE_SYMTAB("acquiring .sbss avma = %#lx .. %#lx\n",
+                         svma + rw_bias, svma + rw_bias + size - 1);
+            TRACE_SYMTAB("acquiring .sbss bias = %#lx\n", di->sbss_bias);
+         } else
+
          if (inrw && size > 0 && !di->sbss_present) {
             di->sbss_present = True;
             di->sbss_svma = svma;