kernel.git/arch/x86/include/asm/elf.h, branch linux-3.17.y

x86: Reject x32 executables if x32 ABI not supported

2014-11-14T18:10:23Z

commit 0e6d3112a4e95d55cf6dca88f298d5f4b8f29bd1 upstream. It is currently possible to execve() an x32 executable on an x86_64 kernel that has only ia32 compat enabled. However all its syscalls will fail, even _exit(). This usually causes it to segfault. Change the ELF compat architecture check so that x32 executables are rejected if we don't support the x32 ABI. Signed-off-by: Ben Hutchings Link: http://lkml.kernel.org/r/1410120305.6822.9.camel@decadent.org.uk Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

x86, vdso: Move the 32-bit vdso special pages after the text

2014-05-05T20:18:56Z

This unifies the vdso mapping code and teaches it how to map special pages at addresses corresponding to symbols in the vdso image. The new code is used for all vdso variants, but so far only the 32-bit variants use the new vvar page position. Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/b6d7858ad7b5ac3fd3c29cab6d6d769bc45d195e.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin

x86, vdso: Reimplement vdso.so preparation in build-time C

2014-05-05T20:18:51Z

Currently, vdso.so files are prepared and analyzed by a combination of objcopy, nm, some linker script tricks, and some simple ELF parsers in the kernel. Replace all of that with plain C code that runs at build time. All five vdso images now generate .c files that are compiled and linked in to the kernel image. This should cause only one userspace-visible change: the loaded vDSO images are stripped more heavily than they used to be. Everything outside the loadable segment is dropped. In particular, this causes the section table and section name strings to be missing. This should be fine: real dynamic loaders don't load or inspect these tables anyway. The result is roughly equivalent to eu-strip's --strip-sections option. The purpose of this change is to enable the vvar and hpet mappings to be moved to the page following the vDSO load segment. Currently, it is possible for the section table to extend into the page after the load segment, so, if we map it, it risks overlapping the vvar or hpet page. This happens whenever the load segment is just under a multiple of PAGE_SIZE. The only real subtlety here is that the old code had a C file with inline assembler that did 'call VDSO32_vsyscall' and a linker script that defined 'VDSO32_vsyscall = __kernel_vsyscall'. This most likely worked by accident: the linker script entry defines a symbol associated with an address as opposed to an alias for the real dynamic symbol __kernel_vsyscall. That caused ld to relocate the reference at link time instead of leaving an interposable dynamic relocation. Since the VDSO32_vsyscall hack is no longer needed, I now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it work. vdso2c will generate an error and abort the build if the resulting image contains any dynamic relocations, so we won't silently generate bad vdso images. (Dynamic relocations are a problem because nothing will even attempt to relocate the vdso.) Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin

x86, vdso: Clean up 32-bit vs 64-bit vdso params

2014-05-05T20:18:40Z

Rather than using 'vdso_enabled' and an awful #define, just call the parameters vdso32_enabled and vdso64_enabled. Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/87913de56bdcbae3d93917938302fc369b05caee.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin

x86, vdso: Remove compat vdso support

2014-03-13T23:20:09Z

The compat vDSO is a complicated hack that's needed to maintain compatibility with a small range of glibc versions. This removes it and replaces it with a much simpler hack: a config option to disable the 32-bit vDSO by default. This also changes the default value of CONFIG_COMPAT_VDSO to n -- users configuring kernels from scratch almost certainly want that choice. Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/4bb4690899106eb11430b1186d5cc66ca9d1660c.1394751608.git.luto@amacapital.net Signed-off-by: H. Peter Anvin

mm: use vm_unmapped_area() on x86_64 architecture

2012-12-12T01:22:25Z

Update the x86_64 arch_get_unmapped_area[_topdown] functions to make use of vm_unmapped_area() instead of implementing a brute force search. Signed-off-by: Michel Lespinasse Reviewed-by: Rik van Riel Cc: Hugh Dickins Cc: Russell King Cc: Ralf Baechle Cc: Paul Mundt Cc: "David S. Miller" Cc: Chris Metcalf Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-03-30T01:12:23Z

Pull x32 support for x86-64 from Ingo Molnar: "This tree introduces the X32 binary format and execution mode for x86: 32-bit data space binaries using 64-bit instructions and 64-bit kernel syscalls. This allows applications whose working set fits into a 32 bits address space to make use of 64-bit instructions while using a 32-bit address space with shorter pointers, more compressed data structures, etc." Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c} * 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) x32: Fix alignment fail in struct compat_siginfo x32: Fix stupid ia32/x32 inversion in the siginfo format x32: Add ptrace for x32 x32: Switch to a 64-bit clock_t x32: Provide separate is_ia32_task() and is_x32_task() predicates x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls x86/x32: Fix the binutils auto-detect x32: Warn and disable rather than error if binutils too old x32: Only clear TIF_X32 flag once x32: Make sure TS_COMPAT is cleared for x32 tasks fs: Remove missed ->fds_bits from cessation use of fd_set structs internally fs: Fix close_on_exec pointer in alloc_fdtable x32: Drop non-__vdso weak symbols from the x32 VDSO x32: Fix coding style violations in the x32 VDSO code x32: Add x32 VDSO support x32: Allow x32 to be configured x32: If configured, add x32 system calls to system call tables x32: Handle process creation x32: Signal-related system calls x86: Add #ifdef CONFIG_COMPAT to ...

Disintegrate asm/system.h for X86

2012-03-28T17:11:12Z

Disintegrate asm/system.h for X86. Signed-off-by: David Howells Acked-by: H. Peter Anvin cc: x86@kernel.org

x32: Fix coding style violations in the x32 VDSO code

2012-02-21T22:32:19Z

Move the prototype for x32_setup_additional_pages() to a header file, and adjust the coding style to match standard. Signed-off-by: H. Peter Anvin Cc: H. J. Lu

x32: Handle process creation

2012-02-20T20:52:05Z

Allow an x32 process to be started. Originally-by: H. J. Lu Signed-off-by: H. Peter Anvin Cc: Peter Zijlstra