linux-dev/arch/x86/boot/boot.h, branch linus/master

Merge tag 'x86_build_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-05-24T01:15:44Z

Pull x86 build updates from Borislav Petkov: - Add a "make x86_debug.config" target which enables a bunch of useful config debug options when trying to debug an issue - A gcc-12 build warnings fix * tag 'x86_build_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Wrap literal addresses in absolute_pointer() x86/configs: Add x86 debugging Kconfig fragment plus docs

x86/boot: Wrap literal addresses in absolute_pointer()

2022-05-19T10:47:30Z

GCC 11 (incorrectly[1]) assumes that literal values cast to (void *) should be treated like a NULL pointer with an offset, and raises diagnostics when doing bounds checking under -Warray-bounds. GCC 12 got "smarter" about finding these: In function 'rdfs8', inlined from 'vga_recalc_vertical' at /srv/code/arch/x86/boot/video-mode.c:124:29, inlined from 'set_mode' at /srv/code/arch/x86/boot/video-mode.c:163:3: /srv/code/arch/x86/boot/boot.h:114:9: warning: array subscript 0 is outside array bounds of 'u8[0]' {aka 'unsigned char[]'} [-Warray-bounds] 114 | asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*(u8 *)addr)); | ^~~ This has been solved in other places[2] already by using the recently added absolute_pointer() macro. Do the same here. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578 [2] https://lore.kernel.org/all/20210912160149.2227137-1-linux@roeck-us.net/ Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20220227195918.705219-1-keescook@chromium.org

x86/boot: Port I/O: Allow to hook up alternative helpers

2022-04-07T15:27:52Z

Port I/O instructions trigger #VE in the TDX environment. In response to the exception, kernel emulates these instructions using hypercalls. But during early boot, on the decompression stage, it is cumbersome to deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE handling. Add a way to hook up alternative port I/O helpers in the boot stub with a new pio_ops structure. For now, set the ops structure to just call the normal I/O operation functions. out*()/in*() macros redefined to use pio_ops callbacks. It eliminates need in changing call sites. io_delay() changed to use port I/O helper instead of inline assembly. Signed-off-by: Kirill A. Shutemov Signed-off-by: Dave Hansen Reviewed-by: Dave Hansen Link: https://lkml.kernel.org/r/20220405232939.73860-16-kirill.shutemov@linux.intel.com

x86: Consolidate port I/O helpers

2022-04-07T15:27:52Z

There are two implementations of port I/O helpers: one in the kernel and one in the boot stub. Move the helpers required for both to and use the one implementation everywhere. Signed-off-by: Kirill A. Shutemov Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20220405232939.73860-15-kirill.shutemov@linux.intel.com

isystem: ship and use stdarg.h

2021-08-19T00:02:55Z

Ship minimal stdarg.h (1 type, 4 macros) as . stdarg.h is the only userspace header commonly used in the kernel. GPL 2 version of can be extracted from http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz Signed-off-by: Alexey Dobriyan Acked-by: Rafael J. Wysocki Acked-by: Ard Biesheuvel Signed-off-by: Masahiro Yamada

x86/boot: Use common BUILD_BUG_ON

2019-08-16T12:15:50Z

Defining BUILD_BUG_ON causes redefinition warnings when adding includes of include/linux/build_bug.h in files unrelated to x86/boot. For example, adding an include of build_bug.h to include/linux/bits.h shows the following warnings: CC arch/x86/boot/cpucheck.o In file included from ./include/linux/bits.h:22, from ./arch/x86/include/asm/msr-index.h:5, from arch/x86/boot/cpucheck.c:28: ./include/linux/build_bug.h:49: warning: "BUILD_BUG_ON" redefined 49 | #define BUILD_BUG_ON(condition) \ | In file included from arch/x86/boot/cpucheck.c:22: arch/x86/boot/boot.h:31: note: this is the location of the previous definition 31 | #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) | The macro was added to boot.h in commit 62bd0337d0c4 ("Top header file for new x86 setup code"). At that time, BUILD_BUG_ON was defined in kernel.h. Presumably BUILD_BUG_ON was redefined to avoid pulling in kernel.h. Since then, BUILD_BUG_ON and similar macros have been split to a separate header file. Signed-off-by: Rikard Falkeborn Signed-off-by: Thomas Gleixner Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20190811184938.1796-2-rikard.falkeborn@gmail.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497

2019-06-19T15:09:53Z

Based on 1 normalized pattern(s): this file is part of the linux kernel and is made available under the terms of the gnu general public license version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 28 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.534229504@linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/boot: Simplify the detect_memory*() control flow

2018-11-06T20:05:01Z

The return values of these functions are not used - so simplify the functions. No change in functionality. [ mingo: Simplified the changelog. ] Suggested: Ingo Molnar Signed-off-by: Jordan Borgner Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20181102145622.zjx2t3mdu3rv6sgy@JordanDesktop Signed-off-by: Ingo Molnar

x86/boot: Fix BSS corruption/overwrite bug in early x86 kernel startup

2017-04-20T08:05:23Z

The minimum size for a new stack (512 bytes) setup for arch/x86/boot components when the bootloader does not setup/provide a stack for the early boot components is not "enough". The setup code executing as part of early kernel startup code, uses the stack beyond 512 bytes and accidentally overwrites and corrupts part of the BSS section. This is exposed mostly in the early video setup code, where it was corrupting BSS variables like force_x, force_y, which in-turn affected kernel parameters such as screen_info (screen_info.orig_video_cols) and later caused an exception/panic in console_init(). Most recent boot loaders setup the stack for early boot components, so this stack overwriting into BSS section issue has not been exposed. Signed-off-by: Ashish Kalra Cc: Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170419152015.10011-1-ashishkalra@Ashishs-MacBook-Pro.local Signed-off-by: Ingo Molnar

x86/boot: Fix KASLR and memmap= collision

2017-01-25T11:35:50Z

CONFIG_RANDOMIZE_BASE=y relocates the kernel to a random base address. However it does not take into account the memmap= parameter passed in from the kernel command line. This results in the kernel sometimes being put in the middle of memmap. Teach KASLR to not insert the kernel in memmap defined regions. We support up to 4 memmap regions: any additional regions will cause KASLR to disable. The mem_avoid set has been augmented to add up to 4 unusable regions of memmaps provided by the user to exclude those regions from the set of valid address range to insert the uncompressed kernel image. The nn@ss ranges will be skipped by the mem_avoid set since it indicates that memory is useable. Signed-off-by: Dave Jiang Reviewed-by: Thomas Gleixner Acked-by: Kees Cook Acked-by: Baoquan He Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: dan.j.williams@intel.com Cc: david@fromorbit.com Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/148417664156.131935.2248592164852799738.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Ingo Molnar