There's a rather nasty bug in elf_aux.c which was uncovered by the
#if/#ifdef patch in -mm2. We have the following:
#if ELF_CLASS == ELFCLASS32
typedef Elf32_auxv_t elf_auxv_t;
#else
typedef Elf64_auxv_t elf_auxv_t;
#endif
Unfortunately, ELFCLASS32 is never defined, so we end up with
Elf64_aux_v_t. The patch correctly added an include of <asm/elf.h> to
define it. However, with Elf32_auxv_t, never file systems don't boot.
This is because UML then recognizes the presence of the vsyscall page
and sets __kernel_vsyscall, vsyscall_ehdr, and vsyscall_end
accordingly.
These seem to end up in UML process' ELF tables, which segfault
endlessly on the non-existant vsyscall page.
So, what is the intent here? Do we want to map the host's vsyscall
page, and just forgot to? Or do we want to tell our processes that
there is no vsyscall page?
In my tree, I have this disabled with this:
Index: linux-2.6.12-rc3-mm2/arch/um/os-Linux/elf_aux.c
===================================================================
--- linux-2.6.12-rc3-mm2.orig/arch/um/os-Linux/elf_aux.c 2005-07-27
14:56:46.000000000 -0400
+++ linux-2.6.12-rc3-mm2/arch/um/os-Linux/elf_aux.c 2005-07-28
10:12:49.000000000 -0400
@@ -57,9 +57,9 @@
break;
}
}
- if ( ! __kernel_vsyscall || ! vsyscall_ehdr ||
+ if (1 /* ! __kernel_vsyscall || ! vsyscall_ehdr ||
! elf_aux_hwcap || ! elf_aux_platform ||
- ! page_size || (vsyscall_ehdr % page_size) ) {
+ ! page_size || (vsyscall_ehdr % page_size) */ ) {
__kernel_vsyscall = 0;
vsyscall_ehdr = 0;
elf_aux_hwcap = 0;
which works, but isn't right.
Jeff
-------------------------------------------------------
SF.Net email is Sponsored by the Better Software Conference & EXPO September
19-22, 2005 * San Francisco, CA * Development Lifecycle Practices
Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA
Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf
_______________________________________________
User-mode-linux-user mailing list
User-mode-linux-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
