As far as I can tell, these fields have been set to zero on save
and ignored on restore since Linux was imported into git.
Rename them '__pad1' and '__pad2' to avoid confusion. This may
also allow us to recycle them some day.
This also adds a comment clarifying the history of those fields.
I'm intentionally avoiding calling either of them '__pad0': the
field formerly known as '__pad0' is now 'ss'.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/844f8490e938780c03355be4c9b69eb4c494bf4e.1426193719.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The comment in the signal code says that apps can save/restore
other segments on their own. It's true that apps can *save* SS
on their own, but there's no way for apps to restore it: SYSCALL
effectively resets SS to __USER_DS, so any value that user code
tries to load into SS gets lost on entry to sigreturn.
This recycles two padding bytes in the segment selector area for SS.
While we're at it, we need a second change to make this useful.
If the signal we're delivering is caused by a bad SS value,
saving that value isn't enough. We need to remove that bad
value from the regs before we try to deliver the signal. Oddly,
the i386 code already got this right.
I suspect that 64-bit programs that try to run 16-bit code and
use signals will have a lot of trouble without this.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/405594361340a2ec32f8e2b115c142df0e180d8e.1426193719.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Check __LP64__ isn't a reliable way to tell if we are compiling for x32
since __LP64__ isnn't specified by x86-64 psABI. Not all x86-64
compilers define __LP64__, which was added to GCC 3.3. The updated x32
psABI:
https://sites.google.com/site/x32abi/documents
definse _ILP32 and __ILP32__ for x32. GCC trunk and 4.7 branch have
been updated to define _ILP32 and __ILP32__ for x32. This patch
replaces __LP64__ check with __ILP32__.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Use explicit sizes (__u64) instead of implicit sizes (unsigned long)
in the definition for sigcontext.h; this will allow this structure to
be shared between the x86-64 native ABI and the x32 ABI.
Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org
"Definition" is misspelled "defintion" in several comments; this
patch fixes them. No code changes.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Impact: save/restore Intel-AVX state properly between tasks
Intel Advanced Vector Extensions (AVX) introduce 256-bit vector processing
capability. More about AVX at http://software.intel.com/sites/avx
Add OS support for YMM state management using xsave/xrstor infrastructure
to support AVX.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1239402084.27006.8057.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix the following 'make headers_check' warnings:
usr/include/asm/sigcontext.h:5: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/asm/sigcontext.h:24: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:
a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
