Pull x86 boot changes from Peter Anvin:
"This patchset is a set of cleanups aiming at librarize some of the
common code from the boot environments. We currently have three
different "little environments" (boot, boot/compressed, and
realmode/rm) in x86, and we are likely to soon get a fourth one
(kexec/purgatory, which will have to be integrated in the kernel to
support secure kexec). This is primarily a cleanup in the
anticipation of the latter.
While Vivek implemented this, he ran into some bugs, in particular the
memcmp implementation for when gcc punts from using the builtin would
have a misnamed symbol, causing compilation errors if we were ever
unlucky enough that gcc didn't want to inline the test"
* 'x86/boot' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, boot: Move memset() definition in compressed/string.c
x86, boot: Move memcmp() into string.h and string.c
x86, boot: Move optimized memcpy() 32/64 bit versions to compressed/string.c
x86, boot: Create a separate string.h file to provide standard string functions
x86, boot: Undef memcmp before providing a new definition
Many Pentium M systems disable PAE but may have a functionally usable PAE
implementation. This adds the "forcepae" parameter which bypasses the boot
check for PAE, and sets the CPU as being PAE capable. Using this parameter
will taint the kernel with TAINT_CPU_OUT_OF_SPEC.
Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Link: http://lkml.kernel.org/r/20140307114040.GA4997@localhost
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Create a separate arch/x86/boot/string.h file to provide declaration of
some of the common string functions.
By default memcpy, memset and memcmp functions will default to gcc
builtin functions. If code wants to use an optimized version of any
of these functions, they need to #undef the respective macro and link
against a local file providing definition of undefed function.
For example, arch/x86/boot/* code links against copy.S to get memcpy()
and memcmp() definitions. arch/86/boot/compressed/* links against
compressed/string.c.
There are quite a few places in arch/x86/ where these functions are
used. Idea is to try to consilidate their declaration and possibly
definitions so that it can be reused.
I am planning to reuse boot/string.h in arch/x86/purgatory/ and use
gcc builtin functions for memcpy, memset and memcmp.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-3-git-send-email-vgoyal@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
When a function is used in more than one file it may not be possible
to immediately tell from context what the intended meaning is. As
such, it is more important that the naming be self-evident. Thus,
change get_flags() to get_cpuflags().
For consistency, change check_flags() to check_cpuflags() even though
it is only used in cpucheck.c.
Link: http://lkml.kernel.org/r/1381450698-28710-2-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Refactor the CPU flags handling out of the cpucheck routines so that
they can be reused by the future ASLR routines (in order to detect CPU
features like RDRAND and RDTSC).
This reworks has_eflag() and has_fpu() to be used on both 32-bit and
64-bit, and refactors the calls to cpuid to make them PIC-safe on 32-bit.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-2-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The CPU feature detection code in the boot code is somewhat minimal,
and doesn't include all possible CPUID words. In particular, it
doesn't contain the code for CPU feature words 2 (Transmeta),
3 (Linux-specific), 5 (VIA), or 7 (scattered). Zero them out, so we
can still set those bits as known at compile time; in particular, this
allows creating a Linux-specific NOPL flag and have it required (and
therefore resolvable at compile time) in 64-bit mode.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Clean up the code for crashes during SpeedStep probing on older
machines.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
yesterday I tried to reactivate my old 486 box and wanted to install a
current Linux with latest kernel on it. But it turned out that the
latest kernel does not boot because the machine crashes early in the
setup code.
After some debugging it turned out that the problem is the query_ist()
function. If this interrupt with that function is called the machine
simply locks up. It looks like a BIOS bug. Looking for a workaround for
this problem I wrote the attached patch. It checks for the CPUID
instruction and if it is not implemented it does not call the speedstep
BIOS function. As far as I know speedstep should be available since some
Pentium earliest.
Alan Cox observed that it's available since the Pentium II, so cpuid
levels 4 and 5 can be excluded altogether.
H. Peter Anvin cleaned up the code some more:
> Right in concept, but I dislike the implementation (duplication of the
> CPU detect code we already have). Could you try this patch and see if
> it works for you?
which, with a small modification to fix a build error with it the
resulting kernel boots on my machine.
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove old comments that include the old arch/i386 directory.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move all CPU definitions to Kconfig.cpu
Always define X86_MINIMUM_CPU_FAMILY and do the
obvious code cleanup in boot/cpucheck.c
Comments from: Adrian Bunk <bunk@kernel.org> incorporated.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Brian Gerst <bgerst@didntduck.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
