kernel/git/stable/linux.git/arch/x86/vdso/vdso32-setup.c, branch master

x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/

2015-06-03T16:51:37+00:00

Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Denys Vlasenko Cc: Brian Gerst Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area

2014-08-08T22:57:27+00:00

The core mm code will provide a default gate area based on FIXADDR_USER_START and FIXADDR_USER_END if !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR). This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit UML, and x86_32 have their own code just to disable it. arm, 32-bit UML, and x86_64 have gate areas, but they have their own implementations. This gets rid of the default and moves the code into ia64. This should save some code on architectures without a gate area: it's now possible to inline the gate_area functions in the default case. Signed-off-by: Andy Lutomirski Acked-by: Nathan Lynch Acked-by: H. Peter Anvin Acked-by: Benjamin Herrenschmidt [in principle] Acked-by: Richard Weinberger [for um] Acked-by: Will Deacon [for arm64] Cc: Catalin Marinas Cc: Will Deacon Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chris Metcalf Cc: Jeff Dike Cc: Richard Weinberger Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Nathan Lynch Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86, mm: Improve _install_special_mapping and fix x86 vdso naming

2014-05-20T18:38:42+00:00

Using arch_vma_name to give special mappings a name is awkward. x86 currently implements it by comparing the start address of the vma to the expected address of the vdso. This requires tracking the start address of special mappings and is probably buggy if a special vma is split or moved. Improve _install_special_mapping to just name the vma directly. Use it to give the x86 vvar area a name, which should make CRIU's life easier. As a side effect, the vvar area will show up in core dumps. This could be considered weird and is fixable. [hpa: I say we accept this as-is but be prepared to deal with knocking out the vvars from core dumps if this becomes a problem.] Cc: Cyrill Gorcunov Cc: Pavel Emelyanov Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/276b39b6b645fb11e345457b503f17b83c2c6fd0.1400538962.git.luto@amacapital.net Signed-off-by: H. Peter Anvin

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

2014-05-05T20:18:56+00:00

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

2014-05-05T20:18:51+00:00

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: Move syscall and sysenter setup into kernel/cpu/common.c

2014-05-05T20:18:47+00:00

This code is used during CPU setup, and it isn't strictly speaking related to the 32-bit vdso. It's easier to understand how this works when the code is closer to its callers. This also lets syscall32_cpu_init be static, which might save some trivial amount of kernel text. Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/4e466987204e232d7b55a53ff6b9739f12237461.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin

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

2014-05-05T20:18:40+00:00

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: Fix size of get_unmapped_area()

2014-03-24T16:31:23+00:00

The size of the reserved memory for a 32 bit vdso must be the size of the 32 bit vDSO in pages + HPET page + VVAR page. One page is not enough for this. Grrrr.... silly copy and paste bug, was right in previous patch. Signed-off-by: Stefani Seibold Cc: Andy Lutomirski Link: http://lkml.kernel.org/r/1395592694-20571-1-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin

x86, vdso: Move more vdso definitions into vdso.h

2014-03-21T03:20:08+00:00

This fixes the Xen build and gets rid of a silly header file. Signed-off-by: Andy Lutomirski Cc: Stefani Seibold Link: http://lkml.kernel.org/r/1df77311795aff75f5742c787d277518314a38d3.1395366931.git.luto@amacapital.net Signed-off-by: H. Peter Anvin

x86: Load the 32-bit vdso in place, just like the 64-bit vdsos

2014-03-20T22:19:14+00:00

This replaces a decent amount of incomprehensible and buggy code with much more straightforward code. It also brings the 32-bit vdso more in line with the 64-bit vdsos, so maybe someday they can share even more code. This wastes a small amount of kernel .data and .text space, but it avoids a couple of allocations on startup, so it should be more or less a wash memory-wise. Signed-off-by: Andy Lutomirski Cc: Stefani Seibold Link: http://lkml.kernel.org/r/b8093933fad09ce181edb08a61dcd5d2592e9814.1395352498.git.luto@amacapital.net Signed-off-by: H. Peter Anvin