Messages in this thread Patch in this message | | | Date | Wed, 18 Jun 2003 15:59:20 +0200 | From | Jakub Jelinek <> | Subject | [PATCH] Fix binfmt_elf.c bug on ppc64 |
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Hi!
Any prelinked shared library is impossible to run on ppc64 without this patch, as they immediately segfault. Say: /bin/echo works even if /lib64/ld64.so.1 is prelinked while /lib64/ld64.so.1 /bin/echo segfaults. The problem is that ELF_PLAT_INIT is passed the virtual address of the shared library, not the difference between the virtual address of the shared library and p_vaddr of the first PT_LOAD segment in that library (while for the interpreter interp_load_address is the bias). ELF_PLAT_INIT sets gpr[2] to this absolute address, but arch/ppc64/kernel/process.c (start_thread) assumes it is a bias and adds it to entry and toc values loaded from the entry point descriptor. For non-prelinked shared libraries, first PT_LOAD segment's p_vaddr is typically 0 and thus load_addr == load_bias (which is why this bug has not been discovered that long).
--- linux-2.5.72/fs/binfmt_elf.c.jj 2003-06-17 06:20:00.000000000 +0200 +++ linux-2.5.72/fs/binfmt_elf.c 2003-06-18 15:47:52.000000000 +0200 @@ -697,7 +697,7 @@ static int load_elf_binary(struct linux_ load_bias += error - ELF_PAGESTART(load_bias + vaddr); load_addr += load_bias; - reloc_func_desc = load_addr; + reloc_func_desc = load_bias; } } k = elf_ppnt->p_vaddr; Jakub - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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