Commit Graph

307 Commits

Author SHA1 Message Date
Andy Lutomirski 61f01dd941 x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue
AMD CPUs don't reinitialize the SS descriptor on SYSRET, so SYSRET with
SS == 0 results in an invalid usermode state in which SS is apparently
equal to __USER_DS but causes #SS if used.

Work around the issue by setting SS to __KERNEL_DS __switch_to, thus
ensuring that SYSRET never happens with SS set to NULL.

This was exposed by a recent vDSO cleanup.

Fixes: e7d6eefaaa x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-26 17:57:38 -07:00
Denys Vlasenko 0f90fb979d x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too
The change which affected how execve clears EXTRA_REGS missed
32-bit execve syscalls.

Fix this by using 64-bit execve stub epilogue for them too.

Run-tested.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-3-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-09 10:31:24 +02:00
Brian Gerst 6a3713f001 x86/signal: Remove pax argument from restore_sigcontext
The 'pax' argument is unnecesary.  Instead, store the RAX value
directly in regs.

This pattern goes all the way back to 2.1.106pre1, when restore_sigcontext()
was changed to return an error code instead of EAX directly:

  https://git.kernel.org/cgit/linux/kernel/git/history/history.git/diff/arch/i386/kernel/signal.c?id=9a8f8b7ca3f319bd668298d447bdf32730e51174

In 2007 sigaltstack syscall support was added, where the return
value of restore_sigcontext() was changed to carry the memory-copying
failure code.

But instead of putting 'ax' into regs->ax directly, it was carried
in via a pointer and then returned, where the generic syscall return
code copied it to regs->ax.

So there was never any deeper reason for this suboptimal pattern, it
was simply never noticed after being introduced.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
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/1428152303-17154-1-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-06 09:06:39 +02:00
Andy Lutomirski 4214a16b02 x86/asm/entry/64/compat: Use SYSRETL to return from compat mode SYSENTER
SYSEXIT is scary on 64-bit kernels -- SYSEXIT must be invoked
with usergs and IRQs on.  That means that we rely on STI to
correctly mask interrupts for one instruction.  This is okay by
itself, but the semantics with respect to NMIs are unclear.

Avoid the whole issue by using SYSRETL instead.  For background,
Intel CPUs don't allow SYSCALL from compat mode, but they do
allow SYSRETL back to compat mode.  Go figure.

To avoid doing too much at once, this doesn't revamp the calling
convention.  We still return with EBP, EDX, and ECX on the user
stack.

Oddly this seems to be 30 cycles or so faster.  Avoiding POPFQ
and STI will account for under half of that, I think, so my best
guess is that Intel just optimizes SYSRET much better than
SYSEXIT.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
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/57a0bf1b5230b2716a64ebe48e9bc1110f7ab433.1428019097.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 09:14:00 +02:00
Denys Vlasenko 4c9c0e919f x86/asm/entry/32: Use smaller PUSH instructions instead of MOV, to build 'pt_regs' on stack
This mimics the recent similar 64-bit change.
Saves ~110 bytes of code.

Patch was run-tested on 32 and 64 bits, Intel and AMD CPU.
I also looked at the diff of entry_64.o disassembly, to have
a different view of the changes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01 13:17:38 +02:00
Denys Vlasenko 4ee8ec17ba x86/asm/entry/32: Make register zero-extension more prominent
There are a couple of syscall argument zero-extension instructions in
the 32-bit compat entry code, and it was mentioned that people keep
trying to optimize them out, introducing bugs.

Make them more visible, and add a "do not remove" comment.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427452582-21624-3-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27 12:27:57 +01:00
Denys Vlasenko a232e3d558 x86/asm/entry/32: Update "interrupt off" comments
The existing comment has proven to be not very clear.

Replace it with a comment similar to the one we now have in the 64-bit
syscall entry point. (Three instances, one per 32-bit syscall entry).

In the INT80 entry point's CFI annotations, replace mysterious
expressions with numric constants. In this case, raw numbers
look more understandable.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427452582-21624-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27 12:27:57 +01:00
Ingo Molnar dca5b52ad7 x86/asm/entry/64: Rename THREAD_INFO() to ASM_THREAD_INFO()
The THREAD_INFO() macro has a somewhat confusingly generic name,
defined in a generic .h C header file. It also does not make it
clear that it constructs a memory operand for use in assembly
code.

Rename it to ASM_THREAD_INFO() to make it all glaringly
obvious on first glance.

Acked-by: Borislav Petkov <bp@suse.de>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/20150324184442.GC14760@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24 20:57:31 +01:00
Ingo Molnar f9d71854b4 x86/asm/entry/64: Merge the field offset into the THREAD_INFO() macro
Before:

   TI_sysenter_return+THREAD_INFO(%rsp,3*8),%r10d

After:

   movl    THREAD_INFO(TI_sysenter_return, %rsp, 3*8), %r10d

to turn it into a clear thread_info accessor.

No code changed:

 md5:
   fb4cb2b3ce05d89940ca304efc8ff183  ia32entry.o.before.asm
   fb4cb2b3ce05d89940ca304efc8ff183  ia32entry.o.after.asm

   e39f2958a5d1300158e276e4f7663263  entry_64.o.before.asm
   e39f2958a5d1300158e276e4f7663263  entry_64.o.after.asm

Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/20150324184411.GB14760@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24 20:57:31 +01:00
Denys Vlasenko ef593260f0 x86/asm/entry: Get rid of KERNEL_STACK_OFFSET
PER_CPU_VAR(kernel_stack) was set up in a way where it points
five stack slots below the top of stack.

Presumably, it was done to avoid one "sub $5*8,%rsp"
in syscall/sysenter code paths, where iret frame needs to be
created by hand.

Ironically, none of them benefits from this optimization,
since all of them need to allocate additional data on stack
(struct pt_regs), so they still have to perform subtraction.

This patch eliminates KERNEL_STACK_OFFSET.

PER_CPU_VAR(kernel_stack) now points directly to top of stack.
pt_regs allocations are adjusted to allocate iret frame as well.
Hopefully we can merge it later with 32-bit specific
PER_CPU_VAR(cpu_current_top_of_stack) variable...

Net result in generated code is that constants in several insns
are changed.

This change is necessary for changing struct pt_regs creation
in SYSCALL64 code path from MOV to PUSH instructions.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1426785469-15125-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24 19:42:38 +01:00
Denys Vlasenko b3fe8ba320 x86/asm/entry/64: Change the THREAD_INFO() definition to not depend on KERNEL_STACK_OFFSET
This changes the THREAD_INFO() definition and all its callsites
so that they do not count stack position from
(top of stack - KERNEL_STACK_OFFSET), but from top of stack.

Semi-mysterious expressions THREAD_INFO(%rsp,RIP) - "why RIP??"
are now replaced by more logical THREAD_INFO(%rsp,SIZEOF_PTREGS)
- "calculate thread_info's address using information that
rsp is SIZEOF_PTREGS bytes below top of stack".

While at it, replace "(off)-THREAD_SIZE(reg)" with equivalent
"((off)-THREAD_SIZE)(reg)". The form without parentheses
falsely looks like we invoke THREAD_SIZE() macro.

Improve comment atop THREAD_INFO macro definition.

This patch does not change generated code (verified by objdump).

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1426785469-15125-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24 19:42:37 +01:00
Brian Gerst 1daeaa3151 x86/asm/entry: Fix execve() and sigreturn() syscalls to always return via IRET
Both the execve() and sigreturn() family of syscalls have the
ability to change registers in ways that may not be compatabile
with the syscall path they were called from.

In particular, SYSRET and SYSEXIT can't handle non-default %cs and %ss,
and some bits in eflags.

These syscalls have stubs that are hardcoded to jump to the IRET path,
and not return to the original syscall path.

The following commit:

   76f5df43ca ("Always allocate a complete "struct pt_regs" on the kernel stack")

recently changed this for some 32-bit compat syscalls, but introduced a bug where
execve from a 32-bit program to a 64-bit program would fail because it still returned
via SYSRETL. This caused Wine to fail when built for both 32-bit and 64-bit.

This patch sets TIF_NOTIFY_RESUME for execve() and sigreturn() so
that the IRET path is always taken on exit to userspace.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1426978461-32089-1-git-send-email-brgerst@gmail.com
[ Improved the changelog and comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 08:52:46 +01:00
Andy Lutomirski 24933b82c0 x86/asm/entry: Rename 'init_tss' to 'cpu_tss'
It has nothing to do with init -- there's only one TSS per cpu.

Other names considered include:

 - current_tss: Confusing because we never switch the tss.
 - singleton_tss: Too long.

This patch was generated with 's/init_tss/cpu_tss/g'.  Followup
patches will fix INIT_TSS and INIT_TSS_IST by hand.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/da29fb2a793e4f649d93ce2d1ed320ebe8516262.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:58 +01:00
Andy Lutomirski 9d0c914c60 x86/asm/entry/64/compat: Change the 32-bit sysenter code to use sp0
The ia32 sysenter code loaded the top of the kernel stack into
rsp by loading kernel_stack and then adjusting it.  It can be
simplified to just read sp0 directly.

This requires the addition of a new asm-offsets entry for sp0.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/88ff9006163d296a0665338585c36d9bfb85235d.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:58 +01:00
Denys Vlasenko b3ab90b333 x86/asm/entry/64/compat: Use more readable constant
The last instance of "mysterious" SS+8 constant is replaced by
SIZEOF_PTREGS.

Message-Id: <1424822419-10267-1-git-send-email-dvlasenk@redhat.com>
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/d35aeba3059407ac54f472ddcfbea767ff8916ac.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:52 +01:00
Denys Vlasenko 14f6e9532d x86/asm/entry/64/compat: Fold the IA32_ARG_FIXUP macro into its callers
Use of a small macro - one with conditional expansion - does
more harm than good. It obfuscates code, with minimal code
reuse.

For example, because of obfuscation it's not obvious that
in 'ia32_sysenter_target', we can optimize loading of r9 -
currently it is loaded with a detour through ebp.

This patch folds the IA32_ARG_FIXUP macro into its callers.

No code changes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/4da092094cd78734384ac31e0d4ec1d8f69145a2.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:52 +01:00
Denys Vlasenko b87cf63e2a x86/asm/entry: Add comments about various syscall instructions
SYSCALL/SYSRET and SYSENTER/SYSEXIT have weird semantics.
Moreover, they differ in 32- and 64-bit mode.

What is saved? What is not? Is rsp set? Are interrupts disabled?
People tend to not remember these details well enough.

This patch adds comments which explain in detail
what registers are modified by each of these instructions.

The comments are placed immediately before corresponding
entry and exit points.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/a94b98b63527797c871a81402ff5060b18fa880a.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:51 +01:00
Denys Vlasenko f2db9382c1 x86/asm/entry: Do mass removal of 'ARGOFFSET'
ARGOFFSET is zero now, removing it changes no code.

A few macros lost "offset" parameter, since it is always zero
now too.

No code changes - verified with objdump.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/8689f937622d9d2db0ab8be82331fa15e4ed4713.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:50 +01:00
Denys Vlasenko 76f5df43ca x86/asm/entry/64: Always allocate a complete "struct pt_regs" on the kernel stack
The 64-bit entry code was using six stack slots less by not
saving/restoring registers which are callee-preserved according
to the C ABI, and was not allocating space for them.

Only when syscalls needed a complete "struct pt_regs" was
the complete area allocated and filled in.

As an additional twist, on interrupt entry a "slightly less
truncated pt_regs" trick is used, to make nested interrupt
stacks easier to unwind.

This proved to be a source of significant obfuscation and subtle
bugs. For example, 'stub_fork' had to pop the return address,
extend the struct, save registers, and push return address back.
Ugly. 'ia32_ptregs_common' pops return address and "returns" via
jmp insn, throwing a wrench into CPU return stack cache.

This patch changes the code to always allocate a complete
"struct pt_regs" on the kernel stack. The saving of registers
is still done lazily.

"Partial pt_regs" trick on interrupt stack is retained.

Macros which manipulate "struct pt_regs" on stack are reworked:

 - ALLOC_PT_GPREGS_ON_STACK allocates the structure.

 - SAVE_C_REGS saves to it those registers which are clobbered
   by C code.

 - SAVE_EXTRA_REGS saves to it all other registers.

 - Corresponding RESTORE_* and REMOVE_PT_GPREGS_FROM_STACK macros
   reverse it.

'ia32_ptregs_common', 'stub_fork' and friends lost their ugly dance
with the return pointer.

LOAD_ARGS32 in ia32entry.S now uses symbolic stack offsets
instead of magic numbers.

'error_entry' and 'save_paranoid' now use SAVE_C_REGS +
SAVE_EXTRA_REGS instead of having it open-coded yet again.

Patch was run-tested: 64-bit executables, 32-bit executables,
strace works.

Timing tests did not show measurable difference in 32-bit
and 64-bit syscalls.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1423778052-21038-2-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/b89763d354aa23e670b9bdf3a40ae320320a7c2e.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:49 +01:00
Ingo Molnar d2c032e3dc Linux 4.0-rc2
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Merge tag 'v4.0-rc2' into x86/asm, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:35:43 +01:00
Brian Gerst 7e8e385aaf x86/compat: Remove sys32_vm86_warning
The check against lastcomm is racy, and the message it produces
isn't necessary.  vm86 support can be disabled on a 32-bit
kernel also, and doesn't have this message.  Switch to
sys_ni_syscall instead.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
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/1425439896-8322-4-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:16:21 +01:00
Brian Gerst 2aa4a71092 x86/compat: Merge native and compat 32-bit syscall tables
Combine the 32-bit syscall tables into one file.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
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/1425439896-8322-3-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:16:21 +01:00
Brian Gerst 29a5ff97fa x86/compat: Remove compat_ni_syscall()
compat_ni_syscall() does the same thing as sys_ni_syscall().

Signed-off-by: Brian Gerst <brgerst@gmail.com>
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/1425439896-8322-2-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:16:21 +01:00
Andy Lutomirski f56141e3e2 all arches, signal: move restart_block to struct task_struct
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Denys Vlasenko 6c3176a216 x86: ia32entry.S: fix wrong symbolic constant usage: R11->ARGOFFSET
The values of these two constants are the same, the meaning is different.

Acked-by: Borislav Petkov <bp@suse.de>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Oleg Nesterov <oleg@redhat.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: X86 ML <x86@kernel.org>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: linux-kernel@vger.kernel.org
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2015-01-13 14:10:31 -08:00
David Drysdale 27d6ec7ad6 x86: hook up execveat system call
Hook up x86-64, i386 and x32 ABIs.

Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Al Viro ba00410b81 Merge branch 'iov_iter' into for-next 2014-12-08 20:39:29 -05:00
Al Viro a455589f18 assorted conversions to %p[dD]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19 13:01:20 -05:00
Andy Lutomirski 653bc77af6 x86_64, entry: Fix out of bounds read on sysenter
Rusty noticed a Really Bad Bug (tm) in my NT fix.  The entry code
reads out of bounds, causing the NT fix to be unreliable.  But, and
this is much, much worse, if your stack is somehow just below the
top of the direct map (or a hole), you read out of bounds and crash.

Excerpt from the crash:

[    1.129513] RSP: 0018:ffff88001da4bf88  EFLAGS: 00010296

  2b:*    f7 84 24 90 00 00 00     testl  $0x4000,0x90(%rsp)

That read is deterministically above the top of the stack.  I
thought I even single-stepped through this code when I wrote it to
check the offset, but I clearly screwed it up.

Fixes: 8c7aa698ba ("x86_64, entry: Filter RFLAGS.NT on entry from userspace")
Reported-by: Rusty Russell <rusty@ozlabs.org>
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-31 18:47:09 -07:00
Linus Torvalds ab074ade9c Merge git://git.infradead.org/users/eparis/audit
Pull audit updates from Eric Paris:
 "So this change across a whole bunch of arches really solves one basic
  problem.  We want to audit when seccomp is killing a process.  seccomp
  hooks in before the audit syscall entry code.  audit_syscall_entry
  took as an argument the arch of the given syscall.  Since the arch is
  part of what makes a syscall number meaningful it's an important part
  of the record, but it isn't available when seccomp shoots the
  syscall...

  For most arch's we have a better way to get the arch (syscall_get_arch)
  So the solution was two fold: Implement syscall_get_arch() everywhere
  there is audit which didn't have it.  Use syscall_get_arch() in the
  seccomp audit code.  Having syscall_get_arch() everywhere meant it was
  a useless flag on the stack and we could get rid of it for the typical
  syscall entry.

  The other changes inside the audit system aren't grand, fixed some
  records that had invalid spaces.  Better locking around the task comm
  field.  Removing some dead functions and structs.  Make some things
  static.  Really minor stuff"

* git://git.infradead.org/users/eparis/audit: (31 commits)
  audit: rename audit_log_remove_rule to disambiguate for trees
  audit: cull redundancy in audit_rule_change
  audit: WARN if audit_rule_change called illegally
  audit: put rule existence check in canonical order
  next: openrisc: Fix build
  audit: get comm using lock to avoid race in string printing
  audit: remove open_arg() function that is never used
  audit: correct AUDIT_GET_FEATURE return message type
  audit: set nlmsg_len for multicast messages.
  audit: use union for audit_field values since they are mutually exclusive
  audit: invalid op= values for rules
  audit: use atomic_t to simplify audit_serial()
  kernel/audit.c: use ARRAY_SIZE instead of sizeof/sizeof[0]
  audit: reduce scope of audit_log_fcaps
  audit: reduce scope of audit_net_id
  audit: arm64: Remove the audit arch argument to audit_syscall_entry
  arm64: audit: Add audit hook in syscall_trace_enter/exit()
  audit: x86: drop arch from __audit_syscall_entry() interface
  sparc: implement is_32bit_task
  sparc: properly conditionalize use of TIF_32BIT
  ...
2014-10-19 16:25:56 -07:00
Linus Torvalds 2fd7476de9 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Misc smaller fixes that missed the v3.17 cycle"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Add arch/x86/purgatory/ make generated files to gitignore
  x86: Fix section conflict for numachip
  x86: Reject x32 executables if x32 ABI not supported
  x86_64, entry: Filter RFLAGS.NT on entry from userspace
  x86, boot, kaslr: Fix nuisance warning on 32-bit builds
2014-10-14 02:28:16 +02:00
Al Viro 19d860a140 handle suicide on late failure exits in execve() in search_binary_handler()
... rather than doing that in the guts of ->load_binary().
[updated to fix the bug spotted by Shentino - for SIGSEGV we really need
something stronger than send_sig_info(); again, better do that in one place]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:00 -04:00
Andy Lutomirski 8c7aa698ba x86_64, entry: Filter RFLAGS.NT on entry from userspace
The NT flag doesn't do anything in long mode other than causing IRET
to #GP.  Oddly, CPL3 code can still set NT using popf.

Entry via hardware or software interrupt clears NT automatically, so
the only relevant entries are fast syscalls.

If user code causes kernel code to run with NT set, then there's at
least some (small) chance that it could cause trouble.  For example,
user code could cause a call to EFI code with NT set, and who knows
what would happen?  Apparently some games on Wine sometimes do
this (!), and, if an IRET return happens, they will segfault.  That
segfault cannot be handled, because signal delivery fails, too.

This patch programs the CPU to clear NT on entry via SYSCALL (both
32-bit and 64-bit, by my reading of the AMD APM), and it clears NT
in software on entry via SYSENTER.

To save a few cycles, this borrows a trick from Jan Beulich in Xen:
it checks whether NT is set before trying to clear it.  As a result,
it seems to have very little effect on SYSENTER performance on my
machine.

There's another minor bug fix in here: it looks like the CFI
annotations were wrong if CONFIG_AUDITSYSCALL=n.

Testers beware: on Xen, SYSENTER with NT set turns into a GPF.

I haven't touched anything on 32-bit kernels.

The syscall mask change comes from a variant of this patch by Anish
Bhatt.

Note to stable maintainers: there is no known security issue here.
A misguided program can set NT and cause the kernel to try and fail
to deliver SIGSEGV, crashing the program.  This patch fixes Far Cry
on Wine: https://bugs.winehq.org/show_bug.cgi?id=33275

Cc: <stable@vger.kernel.org>
Reported-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/395749a5d39a29bd3e4b35899cf3a3c1340e5595.1412189265.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-10-06 10:53:26 -07:00
Richard Guy Briggs b4f0d3755c audit: x86: drop arch from __audit_syscall_entry() interface
Since the arch is found locally in __audit_syscall_entry(), there is no need to
pass it in as a parameter.  Delete it from the parameter list.

x86* was the only arch to call __audit_syscall_entry() directly and did so from
assembly code.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-audit@redhat.com
Signed-off-by: Eric Paris <eparis@redhat.com>

---

As this patch relies on changes in the audit tree, I think it
appropriate to send it through my tree rather than the x86 tree.
2014-09-23 16:21:28 -04:00
Andy Lutomirski 6f121e548f x86, vdso: Reimplement vdso.so preparation in build-time C
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 <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05 13:18:51 -07:00
Al Viro ce39596048 constify copy_siginfo_to_user{,32}()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:29 -05:00
Al Viro 9b56d54380 dump_skip(): dump_seek() replacement taking coredump_params
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:26 -05:00
Al Viro 43a5d548eb aout: switch to dump_emit
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:25 -05:00
Al Viro 7d2f551f6d restore 32bit aout coredump
just getting rid of bitrot

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:22 -05:00
Linus Torvalds f357a82048 Merge branch 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SMAP fixes from Ingo Molnar:
 "Fixes for Intel SMAP support, to fix SIGSEGVs during bootup"

* 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Introduce [compat_]save_altstack_ex() to unbreak x86 SMAP
  x86, smap: Handle csum_partial_copy_*_user()
2013-09-04 11:08:32 -07:00
Linus Torvalds 3d7e5fc37f Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/asm changes from Ingo Molnar:
 "Main changes:

   - Apply low level mutex optimization on x86-64, by Wedson Almeida
     Filho.

   - Change bitops to be naturally 'long', by H Peter Anvin.

   - Add TSX-NI opcodes support to the x86 (instrumentation) decoder, by
     Masami Hiramatsu.

   - Add clang compatibility adjustments/workarounds, by Jan-Simon
     Möller"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, doc: Update uaccess.h comment to reflect clang changes
  x86, asm: Fix a compilation issue with clang
  x86, asm: Extend definitions of _ASM_* with a raw format
  x86, insn: Add new opcodes as of June, 2013
  x86/ia32/asm: Remove unused argument in macro
  x86, bitops: Change bitops to be native operand size
  x86: Use asm-goto to implement mutex fast path on x86-64
2013-09-04 08:39:38 -07:00
Al Viro bd1c149aa9 Introduce [compat_]save_altstack_ex() to unbreak x86 SMAP
For performance reasons, when SMAP is in use, SMAP is left open for an
entire put_user_try { ... } put_user_catch(); block, however, calling
__put_user() in the middle of that block will close SMAP as the
STAC..CLAC constructs intentionally do not nest.

Furthermore, using __put_user() rather than put_user_ex() here is bad
for performance.

Thus, introduce new [compat_]save_altstack_ex() helpers that replace
__[compat_]save_altstack() for x86, being currently the only
architecture which supports put_user_try { ... } put_user_catch().

Reported-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.8+
Link: http://lkml.kernel.org/n/tip-es5p6y64if71k8p5u08agv9n@git.kernel.org
2013-09-01 14:16:33 -07:00
Ramkumar Ramachandra d2475b8ff8 x86/ia32/asm: Remove unused argument in macro
Commit 3fe26fa ("x86: get rid of pt_regs argument in sigreturn variants",
from 2012-11-12) changed the body of PTREGSCALL to drop arg, and
updated the callsites; unfortunately, it forgot to update the
macro argument list, leaving an unused argument.  Fix this.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: http://lkml.kernel.org/r/1373479468-7175-1-git-send-email-artagnon@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23 11:23:21 +02:00
Michel Lespinasse 98d1e64f95 mm: remove free_area_cache
Since all architectures have been converted to use vm_unmapped_area(),
there is no remaining use for the free_area_cache.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10 18:11:34 -07:00
Linus Torvalds f0bb4c0ab0 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "Kernel improvements:

   - watchdog driver improvements by Li Zefan
   - Power7 CPI stack events related improvements by Sukadev Bhattiprolu
   - event multiplexing via hrtimers and other improvements by Stephane
     Eranian
   - kernel stack use optimization by Andrew Hunter
   - AMD IOMMU uncore PMU support by Suravee Suthikulpanit
   - NMI handling rate-limits by Dave Hansen
   - various hw_breakpoint fixes by Oleg Nesterov
   - hw_breakpoint overflow period sampling and related signal handling
     fixes by Jiri Olsa
   - Intel Haswell PMU support by Andi Kleen

  Tooling improvements:

   - Reset SIGTERM handler in workload child process, fix from David
     Ahern.
   - Makefile reorganization, prep work for Kconfig patches, from Jiri
     Olsa.
   - Add automated make test suite, from Jiri Olsa.
   - Add --percent-limit option to 'top' and 'report', from Namhyung
     Kim.
   - Sorting improvements, from Namhyung Kim.
   - Expand definition of sysfs format attribute, from Michael Ellerman.

  Tooling fixes:

   - 'perf tests' fixes from Jiri Olsa.
   - Make Power7 CPI stack events available in sysfs, from Sukadev
     Bhattiprolu.
   - Handle death by SIGTERM in 'perf record', fix from David Ahern.
   - Fix printing of perf_event_paranoid message, from David Ahern.
   - Handle realloc failures in 'perf kvm', from David Ahern.
   - Fix divide by 0 in variance, from David Ahern.
   - Save parent pid in thread struct, from David Ahern.
   - Handle JITed code in shared memory, from Andi Kleen.
   - Fixes for 'perf diff', from Jiri Olsa.
   - Remove some unused struct members, from Jiri Olsa.
   - Add missing liblk.a dependency for python/perf.so, fix from Jiri
     Olsa.
   - Respect CROSS_COMPILE in liblk.a, from Rabin Vincent.
   - No need to do locking when adding hists in perf report, only 'top'
     needs that, from Namhyung Kim.
   - Fix alignment of symbol column in in the hists browser (top,
     report) when -v is given, from NAmhyung Kim.
   - Fix 'perf top' -E option behavior, from Namhyung Kim.
   - Fix bug in isupper() and islower(), from Sukadev Bhattiprolu.
   - Fix compile errors in bp_signal 'perf test', from Sukadev
     Bhattiprolu.

  ... and more things"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (102 commits)
  perf/x86: Disable PEBS-LL in intel_pmu_pebs_disable()
  perf/x86: Fix shared register mutual exclusion enforcement
  perf/x86/intel: Support full width counting
  x86: Add NMI duration tracepoints
  perf: Drop sample rate when sampling is too slow
  x86: Warn when NMI handlers take large amounts of time
  hw_breakpoint: Introduce "struct bp_cpuinfo"
  hw_breakpoint: Simplify *register_wide_hw_breakpoint()
  hw_breakpoint: Introduce cpumask_of_bp()
  hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths
  hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths
  perf/x86/intel: Add mem-loads/stores support for Haswell
  perf/x86/intel: Support Haswell/v4 LBR format
  perf/x86/intel: Move NMI clearing to end of PMI handler
  perf/x86/intel: Add Haswell PEBS support
  perf/x86/intel: Add simple Haswell PMU support
  perf/x86/intel: Add Haswell PEBS record support
  perf/x86/intel: Fix sparse warning
  perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation
  perf/x86/amd: Add IOMMU Performance Counter resource management
  ...
2013-07-02 16:15:23 -07:00
Al Viro 945fb136df aout32 coredump compat fix
dump_seek() does SEEK_CUR, not SEEK_SET; native binfmt_aout
handles it correctly (seeks by PAGE_SIZE - sizeof(struct user),
getting the current position to PAGE_SIZE), compat one seeks
by PAGE_SIZE and ends up at PAGE_SIZE + already written...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-22 11:01:38 +04:00
Jiri Olsa 5e219b3c67 x86/signals: Propagate RF EFLAGS bit through the signal restore call
While porting Vince's perf overflow tests I found perf event
breakpoint overflow does not work properly.

I found the x86 RF EFLAG bit not being set when returning
from debug exception after triggering signal handler. Which
is exactly what you get when you set perf breakpoint overflow
SIGIO handler.

This patch and the next two patches fix the underlying bugs.

This patch adds the RF EFLAGS bit to be restored on return from
signal from the original register context before the signal was
entered.

This will prevent the RF flag to disappear when returning
from exception due to the signal handler being executed.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Originally-Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Stephane Eranian <eranian@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1367421944-19082-2-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-05-28 08:46:50 +02:00
Al Viro 91c2e0bcae unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-09 13:46:38 -04:00
Linus Torvalds 20b4fb4852 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...
2013-05-01 17:51:54 -07:00
Linus Torvalds 08d7676083 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull compat cleanup from Al Viro:
 "Mostly about syscall wrappers this time; there will be another pile
  with patches in the same general area from various people, but I'd
  rather push those after both that and vfs.git pile are in."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  syscalls.h: slightly reduce the jungles of macros
  get rid of union semop in sys_semctl(2) arguments
  make do_mremap() static
  sparc: no need to sign-extend in sync_file_range() wrapper
  ppc compat wrappers for add_key(2) and request_key(2) are pointless
  x86: trim sys_ia32.h
  x86: sys32_kill and sys32_mprotect are pointless
  get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC
  merge compat sys_ipc instances
  consolidate compat lookup_dcookie()
  convert vmsplice to COMPAT_SYSCALL_DEFINE
  switch getrusage() to COMPAT_SYSCALL_DEFINE
  switch epoll_pwait to COMPAT_SYSCALL_DEFINE
  convert sendfile{,64} to COMPAT_SYSCALL_DEFINE
  switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE
  make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect
  make HAVE_SYSCALL_WRAPPERS unconditional
  consolidate cond_syscall and SYSCALL_ALIAS declarations
  teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long
  get rid of duplicate logics in __SC_....[1-6] definitions
2013-05-01 07:21:43 -07:00