[2/2] Make read_program_headers_from_bfd return a gdb::byte_vector
Commit Message
This patch makes read_program_headers_from_bfd return a gdb::byte_vector
instead of a plain pointer.
gdb/ChangeLog:
* solib-svr4.c (read_program_headers_from_bfd): Return
gdb::optional<gdb::byte_vector>.
(svr4_exec_displacement): Adjust.
---
gdb/solib-svr4.c | 58 ++++++++++++++++++------------------------------
1 file changed, 21 insertions(+), 37 deletions(-)
Comments
On Sun, 19 Aug 2018 21:29:47 -0400
Simon Marchi <simon.marchi@polymtl.ca> wrote:
> This patch makes read_program_headers_from_bfd return a gdb::byte_vector
> instead of a plain pointer.
>
> gdb/ChangeLog:
>
> * solib-svr4.c (read_program_headers_from_bfd): Return
> gdb::optional<gdb::byte_vector>.
> (svr4_exec_displacement): Adjust.
LGTM.
Kevin
@@ -2471,28 +2471,20 @@ enable_break (struct svr4_info *info, int from_tty)
return 0;
}
-/* Read the ELF program headers from ABFD. Return the contents and
- set *PHDRS_SIZE to the size of the program headers. */
+/* Read the ELF program headers from ABFD. */
-static gdb_byte *
-read_program_headers_from_bfd (bfd *abfd, int *phdrs_size)
+static gdb::optional<gdb::byte_vector>
+read_program_headers_from_bfd (bfd *abfd)
{
- Elf_Internal_Ehdr *ehdr;
- gdb_byte *buf;
-
- ehdr = elf_elfheader (abfd);
-
- *phdrs_size = ehdr->e_phnum * ehdr->e_phentsize;
- if (*phdrs_size == 0)
- return NULL;
+ Elf_Internal_Ehdr *ehdr = elf_elfheader (abfd);
+ int phdrs_size = ehdr->e_phnum * ehdr->e_phentsize;
+ if (phdrs_size == 0)
+ return {};
- buf = (gdb_byte *) xmalloc (*phdrs_size);
+ gdb::byte_vector buf (phdrs_size);
if (bfd_seek (abfd, ehdr->e_phoff, SEEK_SET) != 0
- || bfd_bread (buf, *phdrs_size, abfd) != *phdrs_size)
- {
- xfree (buf);
- return NULL;
- }
+ || bfd_bread (buf.data (), phdrs_size, abfd) != phdrs_size)
+ return {};
return buf;
}
@@ -2586,16 +2578,15 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
if (bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
{
- /* Be optimistic and clear OK only if GDB was able to verify the headers
+ /* Be optimistic and return 0 only if GDB was able to verify the headers
really do not match. */
- int phdrs2_size, ok = 1;
- gdb_byte *buf2;
int arch_size;
gdb::optional<gdb::byte_vector> phdrs_target
= read_program_header (-1, &arch_size, NULL);
- buf2 = read_program_headers_from_bfd (exec_bfd, &phdrs2_size);
- if (phdrs_target && buf2 != NULL)
+ gdb::optional<gdb::byte_vector> phdrs_binary
+ = read_program_headers_from_bfd (exec_bfd);
+ if (phdrs_target && phdrs_binary)
{
enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
@@ -2612,9 +2603,9 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
content offset for the verification purpose. */
- if (phdrs_target->size () != phdrs2_size
+ if (phdrs_target->size () != phdrs_binary->size ()
|| bfd_get_arch_size (exec_bfd) != arch_size)
- ok = 0;
+ return 0;
else if (arch_size == 32
&& phdrs_target->size () >= sizeof (Elf32_External_Phdr)
&& phdrs_target->size () % sizeof (Elf32_External_Phdr) == 0)
@@ -2672,7 +2663,7 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
phdrp = &((Elf32_External_Phdr *) phdrs_target->data ())[i];
buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
- phdr2p = &((Elf32_External_Phdr *) buf2)[i];
+ phdr2p = &((Elf32_External_Phdr *) phdrs_binary->data ())[i];
/* PT_GNU_STACK is an exception by being never relocated by
prelink as its addresses are always zero. */
@@ -2747,8 +2738,7 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
continue;
}
- ok = 0;
- break;
+ return 0;
}
}
else if (arch_size == 64
@@ -2807,7 +2797,7 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
phdrp = &((Elf64_External_Phdr *) phdrs_target->data ())[i];
buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
- phdr2p = &((Elf64_External_Phdr *) buf2)[i];
+ phdr2p = &((Elf64_External_Phdr *) phdrs_binary->data ())[i];
/* PT_GNU_STACK is an exception by being never relocated by
prelink as its addresses are always zero. */
@@ -2882,18 +2872,12 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
continue;
}
- ok = 0;
- break;
+ return 0;
}
}
else
- ok = 0;
+ return 0;
}
-
- xfree (buf2);
-
- if (!ok)
- return 0;
}
if (info_verbose)