From 5979d6b69b20a8355ea94b75fad97415fce4788c Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Wed, 2 Apr 2014 12:07:33 +1030 Subject: Handle VDSO section headers past end of page When a VDSO gets large enough that it doesn't entirely fit in one page, but not so large that the part described by the program header exceeds one page, then gdb/BFD doesn't read the section headers and symbol table information. This patch cures that by passing the size of the vdso to BFD, and fixes a number of other issues in the BFD code. bfd/ * elfcode.h (bfd_from_remote_memory): Add "size" parameter. Consolidate code handling possible section headers past end of segment. Don't use p_align for page size guess, instead use minpagesize. Take note of ld.so clearing section headers when p_memsz > p_filesz. Handle file header specifying no section headers. Handle zero p_align throughout. Default loadbase to zero. Add comments. Rename contents_size to high_offset, and make it a bfd_vma. Delete unnecessary bfd_set_error calls. * bfd-in.h (bfd_elf_bfd_from_remote_memory): Update prototpe. * elf-bfd.h (struct elf_backend_data ): Likewise. (_bfd_elf32_bfd_from_remote_memory): Likewise. (_bfd_elf64_bfd_from_remote_memory): Likewise. * elf.c (bfd_elf_bfd_from_remote_memory): Adjust. * bfd-in2.h: Regnerate. gdb/ * symfile-mem.c (symbol_file_add_from_memory): Add size parameter. Pass to bfd_elf_bfd_from_remote_memory. Adjust all callers. (struct symbol_file_add_from_memory_args): Add size field. (find_vdso_size): New function. (add_vsyscall_page): Attempt to find vdso size. --- bfd/bfd-in2.h | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) (limited to 'bfd/bfd-in2.h') diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index f08b578..8cfae51 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -687,19 +687,21 @@ extern int bfd_get_elf_phdrs (bfd *abfd, void *phdrs); /* Create a new BFD as if by bfd_openr. Rather than opening a file, - reconstruct an ELF file by reading the segments out of remote memory - based on the ELF file header at EHDR_VMA and the ELF program headers it - points to. If not null, *LOADBASEP is filled in with the difference - between the VMAs from which the segments were read, and the VMAs the - file headers (and hence BFD's idea of each section's VMA) put them at. - - The function TARGET_READ_MEMORY is called to copy LEN bytes from the - remote memory at target address VMA into the local buffer at MYADDR; it - should return zero on success or an `errno' code on failure. TEMPL must - be a BFD for an ELF target with the word size and byte order found in - the remote memory. */ + reconstruct an ELF file by reading the segments out of remote + memory based on the ELF file header at EHDR_VMA and the ELF program + headers it points to. If non-zero, SIZE is the known extent of the + object. If not null, *LOADBASEP is filled in with the difference + between the VMAs from which the segments were read, and the VMAs + the file headers (and hence BFD's idea of each section's VMA) put + them at. + + The function TARGET_READ_MEMORY is called to copy LEN bytes from + the remote memory at target address VMA into the local buffer at + MYADDR; it should return zero on success or an `errno' code on + failure. TEMPL must be a BFD for a target with the word size and + byte order found in the remote memory. */ extern bfd *bfd_elf_bfd_from_remote_memory - (bfd *templ, bfd_vma ehdr_vma, bfd_vma *loadbasep, + (bfd *templ, bfd_vma ehdr_vma, size_t size, bfd_vma *loadbasep, int (*target_read_memory) (bfd_vma vma, bfd_byte *myaddr, bfd_size_type len)); -- cgit v1.1