gdb/
[external/binutils.git] / gdb / solib-svr4.c
index d031303..4a837ca 100644 (file)
@@ -1775,13 +1775,187 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
         really do not match.  */
       int phdrs_size, phdrs2_size, ok = 1;
       gdb_byte *buf, *buf2;
+      int arch_size;
 
-      buf = read_program_header (-1, &phdrs_size, NULL);
+      buf = read_program_header (-1, &phdrs_size, &arch_size);
       buf2 = read_program_headers_from_bfd (exec_bfd, &phdrs2_size);
-      if (buf != NULL && buf2 != NULL
-         && (phdrs_size != phdrs2_size
-             || memcmp (buf, buf2, phdrs_size) != 0))
-       ok = 0;
+      if (buf != NULL && buf2 != NULL)
+       {
+         enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
+
+         /* We are dealing with three different addresses.  EXEC_BFD
+            represents current address in on-disk file.  target memory content
+            may be different from EXEC_BFD as the file may have been prelinked
+            to a different address after the executable has been loaded.
+            Moreover the address of placement in target memory can be
+            different from what the program headers in target memory say - this
+            is the goal of PIE.
+
+            Detected DISPLACEMENT covers both the offsets of PIE placement and
+            possible new prelink performed after start of the program.  Here
+            relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
+            content offset for the verification purpose.  */
+
+         if (phdrs_size != phdrs2_size
+             || bfd_get_arch_size (exec_bfd) != arch_size)
+           ok = 0;
+         else if (arch_size == 32 && phdrs_size >= sizeof (Elf32_External_Phdr)
+                  && phdrs_size % sizeof (Elf32_External_Phdr) == 0)
+           {
+             Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
+             Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
+             CORE_ADDR displacement = 0;
+             int i;
+
+             /* DISPLACEMENT could be found more easily by the difference of
+                ehdr2->e_entry.  But we haven't read the ehdr yet, and we
+                already have enough information to compute that displacement
+                with what we've read.  */
+
+             for (i = 0; i < ehdr2->e_phnum; i++)
+               if (phdr2[i].p_type == PT_LOAD)
+                 {
+                   Elf32_External_Phdr *phdrp;
+                   gdb_byte *buf_vaddr_p, *buf_paddr_p;
+                   CORE_ADDR vaddr, paddr;
+                   CORE_ADDR displacement_vaddr = 0;
+                   CORE_ADDR displacement_paddr = 0;
+
+                   phdrp = &((Elf32_External_Phdr *) buf)[i];
+                   buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+                   buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+
+                   vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
+                                                     byte_order);
+                   displacement_vaddr = vaddr - phdr2[i].p_vaddr;
+
+                   paddr = extract_unsigned_integer (buf_paddr_p, 4,
+                                                     byte_order);
+                   displacement_paddr = paddr - phdr2[i].p_paddr;
+
+                   if (displacement_vaddr == displacement_paddr)
+                     displacement = displacement_vaddr;
+
+                   break;
+                 }
+
+             /* Now compare BUF and BUF2 with optional DISPLACEMENT.  */
+
+             for (i = 0; i < phdrs_size / sizeof (Elf32_External_Phdr); i++)
+               {
+                 Elf32_External_Phdr *phdrp;
+                 Elf32_External_Phdr *phdr2p;
+                 gdb_byte *buf_vaddr_p, *buf_paddr_p;
+                 CORE_ADDR vaddr, paddr;
+
+                 phdrp = &((Elf32_External_Phdr *) buf)[i];
+                 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+                 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+                 phdr2p = &((Elf32_External_Phdr *) buf2)[i];
+
+                 /* PT_GNU_STACK is an exception by being never relocated by
+                    prelink as its addresses are always zero.  */
+
+                 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+                   continue;
+
+                 /* Check also other adjustment combinations - PR 11786.  */
+
+                 vaddr = extract_unsigned_integer (buf_vaddr_p, 4, byte_order);
+                 vaddr -= displacement;
+                 store_unsigned_integer (buf_vaddr_p, 4, byte_order, vaddr);
+
+                 paddr = extract_unsigned_integer (buf_paddr_p, 4, byte_order);
+                 paddr -= displacement;
+                 store_unsigned_integer (buf_paddr_p, 4, byte_order, paddr);
+
+                 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+                   continue;
+
+                 ok = 0;
+                 break;
+               }
+           }
+         else if (arch_size == 64 && phdrs_size >= sizeof (Elf64_External_Phdr)
+                  && phdrs_size % sizeof (Elf64_External_Phdr) == 0)
+           {
+             Elf_Internal_Ehdr *ehdr2 = elf_tdata (exec_bfd)->elf_header;
+             Elf_Internal_Phdr *phdr2 = elf_tdata (exec_bfd)->phdr;
+             CORE_ADDR displacement = 0;
+             int i;
+
+             /* DISPLACEMENT could be found more easily by the difference of
+                ehdr2->e_entry.  But we haven't read the ehdr yet, and we
+                already have enough information to compute that displacement
+                with what we've read.  */
+
+             for (i = 0; i < ehdr2->e_phnum; i++)
+               if (phdr2[i].p_type == PT_LOAD)
+                 {
+                   Elf64_External_Phdr *phdrp;
+                   gdb_byte *buf_vaddr_p, *buf_paddr_p;
+                   CORE_ADDR vaddr, paddr;
+                   CORE_ADDR displacement_vaddr = 0;
+                   CORE_ADDR displacement_paddr = 0;
+
+                   phdrp = &((Elf64_External_Phdr *) buf)[i];
+                   buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+                   buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+
+                   vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
+                                                     byte_order);
+                   displacement_vaddr = vaddr - phdr2[i].p_vaddr;
+
+                   paddr = extract_unsigned_integer (buf_paddr_p, 8,
+                                                     byte_order);
+                   displacement_paddr = paddr - phdr2[i].p_paddr;
+
+                   if (displacement_vaddr == displacement_paddr)
+                     displacement = displacement_vaddr;
+
+                   break;
+                 }
+
+             /* Now compare BUF and BUF2 with optional DISPLACEMENT.  */
+
+             for (i = 0; i < phdrs_size / sizeof (Elf64_External_Phdr); i++)
+               {
+                 Elf64_External_Phdr *phdrp;
+                 Elf64_External_Phdr *phdr2p;
+                 gdb_byte *buf_vaddr_p, *buf_paddr_p;
+                 CORE_ADDR vaddr, paddr;
+
+                 phdrp = &((Elf64_External_Phdr *) buf)[i];
+                 buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
+                 buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
+                 phdr2p = &((Elf64_External_Phdr *) buf2)[i];
+
+                 /* PT_GNU_STACK is an exception by being never relocated by
+                    prelink as its addresses are always zero.  */
+
+                 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+                   continue;
+
+                 /* Check also other adjustment combinations - PR 11786.  */
+
+                 vaddr = extract_unsigned_integer (buf_vaddr_p, 8, byte_order);
+                 vaddr -= displacement;
+                 store_unsigned_integer (buf_vaddr_p, 8, byte_order, vaddr);
+
+                 paddr = extract_unsigned_integer (buf_paddr_p, 8, byte_order);
+                 paddr -= displacement;
+                 store_unsigned_integer (buf_paddr_p, 8, byte_order, paddr);
+
+                 if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
+                   continue;
+
+                 ok = 0;
+                 break;
+               }
+           }
+         else
+           ok = 0;
+       }
 
       xfree (buf);
       xfree (buf2);