Take a look at the first instruction byte before optimizing the NOP -
there might be something else there already, like the ALTERNATIVE_2()
in rdtsc_barrier() which NOPs out on AMD even though we just
patched in an MFENCE.
This happens because the alternatives sees X86_FEATURE_MFENCE_RDTSC,
AMD CPUs set it, we patch in the MFENCE and right afterwards it sees
X86_FEATURE_LFENCE_RDTSC which AMD CPUs don't set and we blindly
optimize the NOP.
Checking whether at least the first byte is 0x90 prevents that.
Signed-off-by: Borislav Petkov <bp@suse.de> 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: 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/1428181662-18020-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86/asm/entry: Clear EXTRA_REGS for all executable formats
On failure, sys_execve() does not clobber EXTRA_REGS, so we can
just return to userpsace without saving/restoring them.
On success, ELF_PLAT_INIT() in sys_execve() clears all these
registers.
On other executable formats:
- binfmt_flat.c has similar FLAT_PLAT_INIT, but x86 (and everyone
else except sh) doesn't define it.
- binfmt_elf_fdpic.c has ELF_FDPIC_PLAT_INIT, but x86 (and most
others) doesn't define it.
- There are no such hooks in binfmt_aout.c et al. We inherit
EXTRA_REGS from the prior executable.
This inconsistency was not intended.
This change removes SAVE/RESTORE_EXTRA_REGS in stub_execve,
removes register clearing in ELF_PLAT_INIT(),
and instead simply clears them on success in stub_execve.
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>
Quentin caught a corner case with the generation of instruction
padding in the ALTERNATIVE_2 macro: if len(orig_insn) <
len(alt1) < len(alt2), then not enough padding gets added and
that is not good(tm) as we could overwrite the beginning of the
next instruction.
Luckily, at the time of this writing, we don't have
ALTERNATIVE_2() invocations which have that problem and even if
we did, a simple fix would be to prepend the instructions with
enough prefixes so that that corner case doesn't happen.
However, best it would be if we fixed it properly. See below for
a simple, abstracted example of what we're doing.
So what we ended up doing is, we compute the
max(len(alt1), len(alt2)) - len(orig_insn)
and feed that value to the .skip gas directive. The max() cannot
have conditionals due to gas limitations, thus the fancy integer
math.
With this patch, all ALTERNATIVE_2 sites get padded correctly;
generating obscure test cases pass too:
x86/asm/entry/64: Fix MSR_IA32_SYSENTER_CS MSR value
Commit:
d56fe4bf5f3c ("x86/asm/entry/64: Always set up SYSENTER MSRs")
missed to add "ULL" to the 0 and wrmsrl_safe() complains:
arch/x86/kernel/cpu/common.c: In function ‘syscall_init’:
arch/x86/kernel/cpu/common.c:1226:2: warning: right shift count >= width of type wrmsrl_safe(MSR_IA32_SYSENTER_CS, 0);
x86/mm/KASLR: Propagate KASLR status to kernel proper
Commit:
e2b32e678513 ("x86, kaslr: randomize module base load address")
made module base address randomization unconditional and didn't regard
disabled KKASLR due to CONFIG_HIBERNATION and command line option
"nokaslr". For more info see (now reverted) commit:
f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation")
In order to propagate KASLR status to kernel proper, we need a single bit
in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the
top-down allocated bits for bits supposed to be used by the bootloader.
Andy Lutomirski [Fri, 3 Apr 2015 00:12:12 +0000 (17:12 -0700)]
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>
Ross Zwisler [Tue, 27 Jan 2015 16:53:51 +0000 (09:53 -0700)]
x86/asm: Add support for the CLWB instruction
Add support for the new CLWB (cache line write back)
instruction. This instruction was announced in the document
"Intel Architecture Instruction Set Extensions Programming
Reference" with reference number 319433-022.
The CLWB instruction is used to write back the contents of
dirtied cache lines to memory without evicting the cache lines
from the processor's cache hierarchy. This should be used in
favor of clflushopt or clflush in cases where you require the
cache line to be written to memory but plan to access the data
again in the near future.
One of the main use cases for this is with persistent memory
where CLWB can be used with PCOMMIT to ensure that data has been
accepted to memory and is durable on the DIMM.
This function shows how to properly use CLWB/CLFLUSHOPT/CLFLUSH
and PCOMMIT with appropriate fencing:
for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
clwb(vaddr);
/* Flush any possible final partial cacheline */
clwb(vend);
/*
* Use SFENCE to order CLWB/CLFLUSHOPT/CLFLUSH cache flushes.
* (MFENCE via mb() also works)
*/
wmb();
/* PCOMMIT and the required SFENCE for ordering */
pcommit_sfence();
}
After this function completes the data pointed to by vaddr is
has been accepted to memory and will be durable if the vaddr
points to persistent memory.
Regarding the details of how the alternatives assembly is set
up, we need one additional byte at the beginning of the CLFLUSH
so that we can flip it into a CLFLUSHOPT by changing that byte
into a 0x66 prefix. Two options are to either insert a 1 byte
ASM_NOP1, or to add a 1 byte NOP_DS_PREFIX. Both have no
functional effect with the plain CLFLUSH, but I've been told
that executing a CLFLUSH + prefix should be faster than
executing a CLFLUSH + NOP.
We had to hard code the assembly for CLWB because, lacking the
ability to assemble the CLWB instruction itself, the next
closest thing is to have an xsaveopt instruction with a 0x66
prefix. Unfortunately XSAVEOPT itself is also relatively new,
and isn't included by all the GCC versions that the kernel needs
to support.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: H. Peter Anvin <hpa@linux.intel.com> 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: 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/1422377631-8986-3-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Boris Ostrovsky [Wed, 1 Apr 2015 14:12:14 +0000 (10:12 -0400)]
x86/cpu: Factor out common CPU initialization code, fix 32-bit Xen PV guests
Some of x86 bare-metal and Xen CPU initialization code is common
between the two and therefore can be factored out to avoid code
duplication.
As a side effect, doing so will also extend the fix provided by
commit a7fcf28d431e ("x86/asm/entry: Replace this_cpu_sp0() with
current_top_of_stack() to x86_32") to 32-bit Xen PV guests.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> 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: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: konrad.wilk@oracle.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1427897534-5086-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Denys Vlasenko [Tue, 31 Mar 2015 17:00:10 +0000 (19:00 +0200)]
x86/asm: Replace "MOVQ $imm, %reg" with MOVL
There is no reason to use MOVQ to load a non-negative immediate
constant value into a 64-bit register. MOVL does the same, since
the upper 32 bits are zero-extended by the CPU.
This makes the code a bit smaller, while leaving functionality
unchanged.
Denys Vlasenko [Tue, 31 Mar 2015 17:00:07 +0000 (19:00 +0200)]
x86/asm/entry/64: Simplify looping around preempt_schedule_irq()
At the 'exit_intr' label we test whether interrupt/exception was in
kernel. If it did, we jump to the preemption check. If preemption
does happen (IOW if we call preempt_schedule_irq()), we go back to
'exit_intr'.
But it's pointless, we already know that the test succeeded last
time, preemption doesn't change the fact that interrupt/exception
was in the kernel.
We can go back directly to checking PER_CPU_VAR(__preempt_count) instead.
Denys Vlasenko [Tue, 31 Mar 2015 17:00:05 +0000 (19:00 +0200)]
x86/asm/entry/64: Simplify retint_kernel label usage, make retint_restore_args label local
Get rid of #define obfuscation of retint_kernel in
CONFIG_PREEMPT case by defining retint_kernel label always, not
only for CONFIG_PREEMPT.
Strip retint_kernel of .global-ness (ENTRY macro) - it has no
users outside of this file.
This looks like cosmetics, but it is not:
"je LABEL" can be optimized to short jump by assember
only if LABEL is not global, for global labels jump is always
a near one with relocation.
Convert retint_restore_args to a local numeric label, making it
clearer that it is not used elsewhere in the file.
Denys Vlasenko [Tue, 31 Mar 2015 17:00:04 +0000 (19:00 +0200)]
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.
Denys Vlasenko [Tue, 31 Mar 2015 17:00:03 +0000 (19:00 +0200)]
x86/asm/entry/64: Do not TRACE_IRQS fast SYSRET64 path
SYSRET code path has a small irq-off block.
On this code path, TRACE_IRQS_ON can't be called right before
interrupts are enabled for real, we can't clobber registers
there. So current code does it earlier, in a safe place.
But with this, TRACE_IRQS_OFF/ON frames just two fast
instructions, which is ridiculous: now most of irq-off block is
_outside_ of the framing.
Do the same thing that we do on SYSCALL entry: do not track this
irq-off block, it is very small to ever cause noticeable irq
latency.
Be careful: make sure that "jnz int_ret_from_sys_call_irqs_off"
now does invoke TRACE_IRQS_OFF - move
int_ret_from_sys_call_irqs_off label before TRACE_IRQS_OFF.
Denys Vlasenko [Mon, 30 Mar 2015 18:09:34 +0000 (20:09 +0200)]
x86/asm/entry/64: Do not GET_THREAD_INFO() too early
At exit_intr, we GET_THREAD_INFO(%rcx) and then jump to
retint_kernel if saved CS was from kernel. But the code at
retint_kernel doesn't need %rcx.
Move GET_THREAD_INFO(%rcx) down, after CS check and branch.
While at it, remove "has a correct top of stack" comment.
After recent changes which eliminated FIXUP_TOP_OF_STACK,
we always have a correct pt_regs layout.
Denys Vlasenko [Mon, 30 Mar 2015 18:09:31 +0000 (20:09 +0200)]
x86/asm/entry/64: Move retint_kernel code block closer to its user
The "retint_kernel" code block is misplaced. Since its logical
continuation is "retint_restore_args", it is more natural to
place it above that label. This also makes two jumps "short".
This change only moves code block around, without changing
logic.
This enables the next simplification: making
"retint_restore_args" label a local numeric one.
Denys Vlasenko [Fri, 27 Mar 2015 10:36:21 +0000 (11:36 +0100)]
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.
Denys Vlasenko [Fri, 27 Mar 2015 10:59:16 +0000 (11:59 +0100)]
x86/asm/entry/64: Fix comment about SYSENTER MSRs
The comment is ancient, it dates to the time when only AMD's
x86_64 implementation existed. AMD wasn't (and still isn't)
supporting SYSENTER, so these writes were "just in case" back
then.
This has changed: Intel's x86_64 appeared, and Intel does
support SYSENTER in long mode. "Some future 64-bit CPU" is here
already.
The code may appear "buggy" for AMD as it stands, since
MSR_IA32_SYSENTER_EIP is only 32-bit for AMD CPUs. Writing a
kernel function's address to it would drop high bits. Subsequent
use of this MSR for branch via SYSENTER seem to allow user to
transition to CPL0 while executing his code. Scary, eh?
Explain why that is not a bug: because SYSENTER insn would not
work on AMD CPU.
Denys Vlasenko [Wed, 25 Mar 2015 20:14:28 +0000 (21:14 +0100)]
x86/irq/tracing: Do not save callee-preserved registers around lockdep_sys_exit_thunk
Internally, lockdep_sys_exit_thunk saves callee-clobbered
registers, and calls a C function, lockdep_sys_exit. Thus,
callee-preserved registers won't be mangled, there is no need to
save them.
Denys Vlasenko [Wed, 25 Mar 2015 17:18:15 +0000 (18:18 +0100)]
x86/asm/entry/64: Use smaller instructions
The $AUDIT_ARCH_X86_64 parameter to syscall_trace_enter_phase1/2
is a 32-bit constant, loading it with 32-bit MOV produces 5-byte
insn instead of 10-byte MOVABS one.
Denys Vlasenko [Wed, 25 Mar 2015 17:18:13 +0000 (18:18 +0100)]
x86/asm/entry/64: Use better label name, fix comments
A named label "ret_from_sys_call" implies that there are jumps
to this location from elsewhere, as happens with many other
labels in this file.
But this label is used only by the JMP a few insns above.
To make that obvious, use local numeric label instead.
Improve comments:
"and return regs->ax" isn't too informative. We always return
regs->ax.
The comment suggesting that it'd be cool to use rip relative
addressing for CALL is deleted. It's unclear why that would be
an improvement - we aren't striving to use position-independent
code here. PIC code here would require something like LEA
sys_call_table(%rip),reg + CALL *(reg,%rax*8)...
"iret frame is also incomplete" is no longer true, fix that too.
Andy Lutomirski [Mon, 23 Mar 2015 19:32:54 +0000 (12:32 -0700)]
x86/asm/entry: Check for syscall exit work with IRQs disabled
We currently have a race: if we're preempted during syscall
exit, we can fail to process syscall return work that is queued
up while we're preempted in ret_from_sys_call after checking
ti.flags.
Fix it by disabling interrupts before checking ti.flags.
Ingo Molnar [Tue, 24 Mar 2015 18:44:42 +0000 (19:44 +0100)]
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>
Denys Vlasenko [Sun, 22 Mar 2015 21:01:12 +0000 (22:01 +0100)]
x86/asm: Deobfuscate segment.h
This file just defines a number of constants, and a few macros
and inline functions. It is particularly badly written.
For example, it is not trivial to see how descriptors are
numbered (you'd expect that should be easy, right?).
This change deobfuscates it via the following changes:
Group all GDT_ENTRY_foo together (move intervening stuff away).
Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3:
I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18.
Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful.
The above change allows to remove GDT_ENTRY_KERNEL_BASE
and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else.
After a group of GDT_ENTRY_foo, define all selector values.
Remove or improve some comments. In particular:
Comment deleted as stating the obvious:
/*
* The GDT has 32 entries
*/
#define GDT_ENTRIES 32
"The segment offset needs to contain a RPL. Grr. -AK"
changed to
"Selectors need to also have a correct RPL (+3 thingy)"
"GDT layout to get 64bit syscall right (sysret hardcodes gdt
offsets)" expanded into a description *how exactly* sysret
hardcodes them.
Patch was tested to compile and not change vmlinux.o
on 32-bit and 64-bit builds (verified with objdump).
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> 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> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Denys Vlasenko [Thu, 19 Mar 2015 17:17:48 +0000 (18:17 +0100)]
x86/asm/entry/64: Get rid of the FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK macros
The FIXUP_TOP_OF_STACK macro is only necessary because we don't save %r11
to pt_regs->r11 on SYSCALL64 fast path, but we want ptrace to see it populated.
Bite the bullet, add a single additional PUSH instruction, and remove
the FIXUP_TOP_OF_STACK macro.
The RESTORE_TOP_OF_STACK macro is already a nop. Remove it too.
On SandyBridge CPU, it does not get slower:
measured 54.22 ns per getpid syscall before and after last two
changes on defconfig kernel.
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/1426785469-15125-4-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Denys Vlasenko [Thu, 19 Mar 2015 17:17:47 +0000 (18:17 +0100)]
x86/asm/entry/64: Use PUSH instructions to build pt_regs on stack
With this change, on SYSCALL64 code path we are now populating
pt_regs->cs, pt_regs->ss and pt_regs->rcx unconditionally and
therefore don't need to do that in FIXUP_TOP_OF_STACK.
We lose a number of large instructions there:
text data bss dec hex filename
13298 0 0 13298 33f2 entry_64_before.o
12978 0 0 12978 32b2 entry_64.o
What's more important, we convert two "MOVQ $imm,off(%rsp)" to
"PUSH $imm" (the ones which fill pt_regs->cs,ss).
Before this patch, placing them on fast path was slowing it down
by two cycles: this form of MOV is very large, 12 bytes, and
this probably reduces decode bandwidth to one instruction per cycle
when CPU sees them.
Therefore they were living in FIXUP_TOP_OF_STACK instead (away
from fast path).
"PUSH $imm" is a small 2-byte instruction. Moving it to fast path does
not slow it down in my measurements.
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/1426785469-15125-3-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Denys Vlasenko [Thu, 19 Mar 2015 17:17:46 +0000 (18:17 +0100)]
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>
Denys Vlasenko [Thu, 19 Mar 2015 17:17:45 +0000 (18:17 +0100)]
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.
Denys Vlasenko [Sun, 22 Mar 2015 19:48:14 +0000 (20:48 +0100)]
x86/asm/entry/64: Fold syscall32_cpu_init() into its sole user
Having syscall32/sysenter32 initialization in a separate tiny
function, called from within a function that is already syscall
init specific, serves no real purpose.
Its existense also caused an unintended effect of having
wrmsrl(MSR_CSTAR) performed twice: once we set it to a dummy
function returning -ENOSYS, and immediately after
(if CONFIG_IA32_EMULATION), we set it to point to the proper
syscall32 entry point, ia32_cstar_target.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.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> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Thu, 19 Mar 2015 01:33:32 +0000 (18:33 -0700)]
x86/asm/entry: Make user_mode() work correctly if regs came from VM86 mode
user_mode() is now identical to user_mode_vm(). Subsequent patches
will change all callers of user_mode_vm() to user_mode() and then
delete user_mode_vm().
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> 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/0dd03eacb5f0a2b5ba0240de25347a31b493c289.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Thu, 19 Mar 2015 01:33:29 +0000 (18:33 -0700)]
x86/asm/entry: Add user_mode_ignore_vm86()
user_mode() is dangerous and user_mode_vm() has a confusing name.
Add user_mode_ignore_vm86() (equivalent to current user_mode()).
We'll change the small number of legitimate users of user_mode()
to user_mode_ignore_vm86().
Inspired by grsec, although this works rather differently.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> 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/202c56ca63823c338af8e2e54948dbe222da6343.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Thu, 19 Mar 2015 01:33:27 +0000 (18:33 -0700)]
x86/mm/fault: Use TASK_SIZE_MAX in is_prefetch()
This is slightly shorter and slightly faster. It's also more
correct: the split between user and kernel addresses is
TASK_SIZE_MAX, regardless of ti->flags.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> 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/09156b63bad90a327827003c9e53faa82ef4c56e.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Brian Gerst [Sat, 21 Mar 2015 22:54:21 +0000 (18:54 -0400)]
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:
76f5df43cab5e76 ("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>
Linus Torvalds [Sun, 22 Mar 2015 19:07:47 +0000 (12:07 -0700)]
Merge tag 'driver-core-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are two bugfixes for things reported. One regression in kernfs,
and another issue fixed in the LZ4 code that was fixed in the
"upstream" codebase that solves a reported kernel crash
Both have been in linux-next for a while"
* tag 'driver-core-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
LZ4 : fix the data abort issue
kernfs: handle poll correctly on 'direct_read' files.
Linus Torvalds [Sun, 22 Mar 2015 19:03:14 +0000 (12:03 -0700)]
Merge tag 'char-misc-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc fixes from Greg KH:
"Here are three fixes for 4.0-rc5 that revert 3 PCMCIA patches that
were merged in 4.0-rc1 that cause regressions. So let's revert them
for now and they will be reworked and resent sometime in the future.
All have been tested in linux-next for a while"
* tag 'char-misc-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
Revert "pcmcia: add a new resource manager for non ISA systems"
Revert "pcmcia: fix incorrect bracketing on a test"
Revert "pcmcia: add missing include for new pci resource handler"
Linus Torvalds [Sun, 22 Mar 2015 18:59:02 +0000 (11:59 -0700)]
Merge tag 'staging-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver fixes from Greg KH:
"Here are four small staging driver fixes, all for the vt6656 and
vt6655 drivers, that resolve some reported issues with them.
All of these patches have been in linux next for a while"
* tag 'staging-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
vt6655: Fix late setting of byRFType.
vt6655: RFbSetPower fix missing rate RATE_12M
staging: vt6656: vnt_rf_setpower: fix missing rate RATE_12M
staging: vt6655: vnt_tx_packet fix dma_idx selection.
Linus Torvalds [Sun, 22 Mar 2015 18:54:29 +0000 (11:54 -0700)]
Merge tag 'tty-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fix from Greg KH:
"Here's a single 8250 serial driver that fixes a reported deadlock with
the serial console and the tty driver.
It's been in linux-next for a while now"
* tag 'tty-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: 8250_dw: Fix deadlock in LCR workaround
Linus Torvalds [Sun, 22 Mar 2015 18:33:55 +0000 (11:33 -0700)]
Merge tag 'usb-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB / PHY driver fixes from Greg KH:
"Here's a number of USB and PHY driver fixes for 4.0-rc5.
The largest thing here is a revert of a gadget function driver patch
that removes 500 lines of code. Other than that, it's a number of
reported bugs fixes and new quirk/id entries.
All have been in linux-next for a while"
* tag 'usb-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
usb: common: otg-fsm: only signal connect after switching to peripheral
uas: Add US_FL_NO_ATA_1X for Initio Corporation controllers / devices
USB: ehci-atmel: rework clk handling
MAINTAINERS: add entry for USB OTG FSM
usb: chipidea: otg: add a_alt_hnp_support response for B device
phy: omap-usb2: Fix missing clk_prepare call when using old dt name
phy: ti/omap: Fix modalias
phy: core: Fixup return value of phy_exit when !pm_runtime_enabled
phy: miphy28lp: Convert to devm_kcalloc and fix wrong sizof
phy: miphy365x: Convert to devm_kcalloc and fix wrong sizeof
phy: twl4030-usb: Remove redundant assignment for twl->linkstat
phy: exynos5-usbdrd: Fix off-by-one valid value checking for args->args[0]
phy: Find the right match in devm_phy_destroy()
phy: rockchip-usb: Fixup rockchip_usb_phy_power_on failure path
phy: ti-pipe3: Simplify ti_pipe3_dpll_wait_lock implementation
phy: samsung-usb2: Remove NULL terminating entry from phys array
phy: hix5hd2-sata: Check return value of platform_get_resource
phy: exynos-dp-video: Kill exynos_dp_video_phy_pwr_isol function
Revert "usb: gadget: zero: Add support for interrupt EP"
Revert "xhci: Clear the host side toggle manually when endpoint is 'soft reset'"
...
Linus Torvalds [Sat, 21 Mar 2015 20:05:37 +0000 (13:05 -0700)]
Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave dmaengine fixes from Vinod Koul:
"Four fixes for dw, pl08x, imx-sdma and at_hdmac driver. Nothing
unusual here, simple fixes to these drivers"
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: pl08x: Define capabilities for generic capabilities reporting
dmaengine: dw: append MODULE_ALIAS for platform driver
dmaengine: imx-sdma: switch to dynamic context mode after script loaded
dmaengine: at_hdmac: Fix calculation of the residual bytes
Linus Torvalds [Sat, 21 Mar 2015 19:51:36 +0000 (12:51 -0700)]
Merge tag 'pm+acpi-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI fixes from Rafael Wysocki:
"These are fixes for recent regressions (PCI/ACPI resources and at91
RTC locking), a stable-candidate powercap RAPL driver fix and two ARM
cpuidle fixes (one stable-candidate too).
Specifics:
- Revert a recent PCI commit related to IRQ resources management that
introduced a regression for drivers attempting to bind to devices
whose previous drivers did not balance pci_enable_device() and
pci_disable_device() as expected (Rafael J Wysocki).
- Fix a deadlock in at91_rtc_interrupt() introduced by a typo in a
recent commit related to wakeup interrupt handling (Dan Carpenter).
- Allow the power capping RAPL (Running-Average Power Limit) driver
to use different energy units for domains within one CPU package
which is necessary to handle Intel Haswell EP processors correctly
(Jacob Pan).
- Improve the cpuidle mvebu driver's handling of Armada XP SoCs by
updating the target residency and exit latency numbers for those
chips (Sebastien Rannou).
- Prevent the cpuidle mvebu driver from calling cpu_pm_enter() twice
in a row before cpu_pm_exit() is called on the same CPU which
breaks the core's assumptions regarding the usage of those
functions (Gregory Clement)"
* tag 'pm+acpi-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
Revert "x86/PCI: Refine the way to release PCI IRQ resources"
rtc: at91rm9200: double locking bug in at91_rtc_interrupt()
powercap / RAPL: handle domains with different energy units
cpuidle: mvebu: Update cpuidle thresholds for Armada XP SOCs
cpuidle: mvebu: Fix the CPU PM notifier usage
Linus Torvalds [Sat, 21 Mar 2015 19:41:50 +0000 (12:41 -0700)]
Merge git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
"A bunch of fixes across drivers:
radeon:
disable two ended allocation for now, it breaks some stuff
amdkfd:
misc fixes
nouveau:
fix irq loop problem, add basic support for GM206 (new hw)
i915:
fix some WARNs people were seeing
exynos:
fix some iommu interactions causing boot failures"
* git://people.freedesktop.org/~airlied/linux:
drm/radeon: drop ttm two ended allocation
drm/exynos: fix the initialization order in FIMD
drm/exynos: fix typo config name correctly.
drm/exynos: Check for NULL dereference of crtc
drm/exynos: IS_ERR() vs NULL bug
drm/exynos: remove unused files
drm/i915: Make sure the primary plane is enabled before reading out the fb state
drm/nouveau/bios: fix i2c table parsing for dcb 4.1
drm/nouveau/device/gm100: Basic GM206 bring up (as copy of GM204)
drm/nouveau/device: post write to NV_PMC_BOOT_1 when flipping endian switch
drm/nouveau/gr/gf100: fix some accidental or'ing of buffer addresses
drm/nouveau/fifo/nv04: remove the loop from the interrupt handler
drm/radeon: Changing number of compute pipe lines
drm/amdkfd: Fix SDMA queue init. in non-HWS mode
drm/amdkfd: destroy mqd when destroying kernel queue
drm/i915: Ensure plane->state->fb stays in sync with plane->fb
Linus Torvalds [Sat, 21 Mar 2015 19:33:01 +0000 (12:33 -0700)]
Merge tag 'devicetree-fixes-for-4.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull more DeviceTree fixes vfom Rob Herring:
- revert setting stdout-path as preferred console. This caused
regressions in PowerMACs and other systems.
- yet another fix for stdout-path option parsing.
- fix error path handling in of_irq_parse_one
* tag 'devicetree-fixes-for-4.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
Revert "of: Fix premature bootconsole disable with 'stdout-path'"
of: handle both '/' and ':' in path strings
of: unittest: Add option string test case with longer path
of/irq: Fix of_irq_parse_one() returned error codes
Pull SCSI target fixes from Nicholas Bellinger:
"Here are current target-pending fixes for v4.0-rc5 code that have made
their way into the queue over the last weeks.
The fixes this round include:
- Fix long-standing iser-target logout bug related to early
conn_logout_comp completion, resulting in iscsi_conn use-after-tree
OOpsen. (Sagi + nab)
- Fix long-standing tcm_fc bug in ft_invl_hw_context() failure
handing for DDP hw offload. (DanC)
- Fix incorrect use of unprotected __transport_register_session() in
tcm_qla2xxx + other single local se_node_acl fabrics. (Bart)
- Fix reference leak in target_submit_cmd() -> target_get_sess_cmd()
for ack_kref=1 failure path. (Bart)
* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0
target: Fix virtual LUN=0 target_configure_device failure OOPs
target/pscsi: Fix NULL pointer dereference in get_device_type
tcm_fc: missing curly braces in ft_invl_hw_context()
target: Fix reference leak in target_get_sess_cmd() error path
loop/usb/vhost-scsi/xen-scsiback: Fix use of __transport_register_session
tcm_qla2xxx: Fix incorrect use of __transport_register_session
iscsi-target: Avoid early conn_logout_comp for iser connections
Revert "iscsi-target: Avoid IN_LOGOUT failure case for iser-target"
target: Disallow changing of WRITE cache/FUA attrs after export
Linus Torvalds [Sat, 21 Mar 2015 18:15:13 +0000 (11:15 -0700)]
Merge tag 'dm-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull devicemapper fixes from Mike Snitzer:
"A handful of stable fixes for DM:
- fix thin target to always zero-fill reads to unprovisioned blocks
- fix to interlock device destruction's suspend from internal
suspends
- fix 2 snapshot exception store handover bugs
- fix dm-io to cope with DISCARD and WRITE_SAME capabilities changing"
* tag 'dm-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm io: deal with wandering queue limits when handling REQ_DISCARD and REQ_WRITE_SAME
dm snapshot: suspend merging snapshot when doing exception handover
dm snapshot: suspend origin when doing exception handover
dm: hold suspend_lock while suspending device during device deletion
dm thin: fix to consistently zero-fill reads to unprovisioned blocks
Linus Torvalds [Sat, 21 Mar 2015 17:53:37 +0000 (10:53 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"Most of these are fixing extent reservation accounting, or corners
with tree writeback during commit.
Josef's set does add a test, which isn't strictly a fix, but it'll
keep us from making this same mistake again"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix outstanding_extents accounting in DIO
Btrfs: add sanity test for outstanding_extents accounting
Btrfs: just free dummy extent buffers
Btrfs: account merges/splits properly
Btrfs: prepare block group cache before writing
Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
Btrfs: account for the correct number of extents for delalloc reservations
Btrfs: fix merge delalloc logic
Btrfs: fix comp_oper to get right order
Btrfs: catch transaction abortion after waiting for it
btrfs: fix sizeof format specifier in btrfs_check_super_valid()
Linus Torvalds [Sat, 21 Mar 2015 17:24:10 +0000 (10:24 -0700)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- mm switching fix where the kernel pgd ends up in the user TTBR0 after
returning from an EFI run-time services call
- fix __GFP_ZERO handling for atomic pool and CMA DMA allocations (the
generic code does get the gfp flags, so it's left with the arch code
to memzero accordingly)
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: Honor __GFP_ZERO in dma allocations
arm64: efi: don't restore TTBR0 if active_mm points at init_mm
Linus Torvalds [Sat, 21 Mar 2015 17:03:22 +0000 (10:03 -0700)]
Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
"Another few ARM fixes. Fabrice fixed the L2 cache DT parsing to allow
prefetch configuration to be specified even when the cache size
parsing fails.
Laura noticed that the setting of page attributes wasn't working for
modules due to is_module_addr() always returning false.
Marc Gonzalez (aka Mason) noticed a potential latent bug with the way
we read one of the CPUID registers (where we could attempt to read a
non-present CPUID register which may fault.)
I've fixed an issue where 32-bit DMA masks were failing with memory
which extended to the top of physical address space, and I've also
added debugging output of the page tables when we hit a data access
exception which we don't specifically handle - prompted by the lack of
information in a bug report"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8313/1: Use read_cpuid_ext() macro instead of inline asm
ARM: 8311/1: Don't use is_module_addr in setting page attributes
ARM: 8310/1: l2c: Fix prefetch settings dt parsing
ARM: dump pgd, pmd and pte states on unhandled data abort faults
ARM: dma-api: fix off-by-one error in __dma_supported()
NeilBrown [Fri, 13 Mar 2015 00:51:18 +0000 (11:51 +1100)]
md: fix problems with freeing private data after ->run failure.
If ->run() fails, it can either free the data structures it
allocated, or leave that task to ->free() which will be called
on failures.
However:
md.c calls ->free() even if ->private_data is NULL, which
causes problems in some personalities.
raid0.c frees the data, but doesn't clear ->private_data,
which will become a problem when we fix md.c
So better fix both these issues at once.
Reported-by: Richard W.M. Jones <rjones@redhat.com> Fixes: 5aa61f427e4979be733e4847b9199ff9cc48a47e
URL: https://bugzilla.kernel.org/show_bug.cgi?id=94381 Signed-off-by: NeilBrown <neilb@suse.de>
Will Deacon [Thu, 19 Mar 2015 15:43:00 +0000 (15:43 +0000)]
arm64: efi: don't restore TTBR0 if active_mm points at init_mm
init_mm isn't a normal mm: it has swapper_pg_dir as its pgd (which
contains kernel mappings) and is used as the active_mm for the idle
thread.
When restoring the pgd after an EFI call, we write current->active_mm
into TTBR0. If the current task is actually the idle thread (e.g. when
initialising the EFI RTC before entering userspace), then the TLB can
erroneously populate itself with junk global entries as a result of
speculative table walks.
When we do eventually return to userspace, the task can end up hitting
these junk mappings leading to lockups, corruption or crashes.
This patch fixes the problem in the same way as the CPU suspend code by
ensuring that we never switch to the init_mm in efi_set_pgd and instead
point TTBR0 at the zero page. A check is also added to cpu_switch_mm to
BUG if we get passed swapper_pg_dir.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: f3cdfd239da5 ("arm64/efi: move SetVirtualAddressMap() to UEFI stub") Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Revert "x86/PCI: Refine the way to release PCI IRQ resources"
Commit b4b55cda5874 (Refine the way to release PCI IRQ resources)
introduced a regression in the PCI IRQ resource management by causing
the IRQ resource of a device, established when pci_enabled_device()
is called on a fully disabled device, to be released when the driver
is unbound from the device, regardless of the enable_cnt.
This leads to the situation that an ill-behaved driver can now make a
device unusable to subsequent drivers by an imbalance in their use of
pci_enable/disable_device(). That is a serious problem for secondary
drivers like vfio-pci, which are innocent of the transgressions of
the previous driver.
Since the solution of this problem is not immediate and requires
further discussion, revert commit b4b55cda5874 and the issue it was
supposed to address (a bug related to xen-pciback) will be taken
care of in a different way going forward.
Reported-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Dave Airlie [Fri, 20 Mar 2015 07:32:21 +0000 (17:32 +1000)]
Merge tag 'drm-intel-fixes-2015-03-19' of git://anongit.freedesktop.org/drm-intel into drm-fixes
Backporting a couple of plane related fixes from drm-next to v4.0.
* tag 'drm-intel-fixes-2015-03-19' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Make sure the primary plane is enabled before reading out the fb state
drm/i915: Ensure plane->state->fb stays in sync with plane->fb
Dave Airlie [Fri, 20 Mar 2015 07:32:01 +0000 (17:32 +1000)]
Merge tag 'drm-amdkfd-fixes-2015-03-19' of git://people.freedesktop.org/~gabbayo/linux into drm-fixes
- Fixing SDMA initialization when in non-HWS mode (debug mode)
- Memory leak fix when destroying kernel queue
- Fix number of available compute pipelines according to new firmware
* tag 'drm-amdkfd-fixes-2015-03-19' of git://people.freedesktop.org/~gabbayo/linux:
drm/radeon: Changing number of compute pipe lines
drm/amdkfd: Fix SDMA queue init. in non-HWS mode
drm/amdkfd: destroy mqd when destroying kernel queue
target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0
A check that rejects a CDB with FUA bit set if no write cache is
emulated was added by the following commit:
fde9f50 target: Add sanity checks for DPO/FUA bit usage
The condition is as follows:
if (!dev->dev_attrib.emulate_fua_write ||
!dev->dev_attrib.emulate_write_cache)
However, this check is wrong if the backend device supports WCE but
"emulate_write_cache" is disabled.
This patch uses se_dev_check_wce() (previously named
spc_check_dev_wce) to invoke transport->get_write_cache() if the
device has a write cache or check the "emulate_write_cache" attribute
otherwise.
Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a NULL pointer dereference triggered by a late
target_configure_device() -> alloc_workqueue() failure that results
in target_free_device() being called with DF_CONFIGURED already set,
which subsequently OOPses in destroy_workqueue() code.
Currently this only happens at modprobe target_core_mod time when
core_dev_setup_virtual_lun0() -> target_configure_device() fails,
and the explicit target_free_device() gets called.
To address this bug originally introduced by commit 0fd97ccf45, go
ahead and move DF_CONFIGURED to end of target_configure_device()
code to handle this special failure case.
Reported-by: Claudio Fleiner <cmf@daterainc.com> Cc: Claudio Fleiner <cmf@daterainc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <stable@vger.kernel.org> # v3.7+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
target/pscsi: Fix NULL pointer dereference in get_device_type
This patch fixes a NULL pointer dereference OOPs with pSCSI backends
within target_core_stat.c code. The bug is caused by a configfs attr
read if no pscsi_dev_virt->pdv_sd has been configured.
Reported-by: Olaf Hering <olaf@aepfle.de> Cc: <stable@vger.kernel.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Dan Carpenter [Wed, 25 Feb 2015 13:21:03 +0000 (16:21 +0300)]
tcm_fc: missing curly braces in ft_invl_hw_context()
This patch adds a missing set of conditional check braces in
ft_invl_hw_context() originally introduced by commit dcd998ccd
when handling DDP failures in ft_recv_write_data() code.
Bart Van Assche [Thu, 12 Feb 2015 10:48:49 +0000 (11:48 +0100)]
loop/usb/vhost-scsi/xen-scsiback: Fix use of __transport_register_session
This patch changes loopback, usb-gadget, vhost-scsi and xen-scsiback
fabric code to invoke transport_register_session() instead of the
unprotected flavour, to ensure se_tpg->session_lock is taken when
adding new session list nodes to se_tpg->tpg_sess_list.
Note that since these four fabric drivers already hold their own
internal TPG mutexes when accessing se_tpg->tpg_sess_list, and
consist of a single se_session created through configfs attribute
access, no list corruption can currently occur.
So for correctness sake, go ahead and use the se_tpg->session_lock
protected version for these four fabric drivers.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Bart Van Assche [Fri, 20 Mar 2015 05:25:16 +0000 (22:25 -0700)]
tcm_qla2xxx: Fix incorrect use of __transport_register_session
This patch fixes the incorrect use of __transport_register_session()
in tcm_qla2xxx_check_initiator_node_acl() code, that does not perform
explicit se_tpg->session_lock when accessing se_tpg->tpg_sess_list
to add new se_sess nodes.
Given that tcm_qla2xxx_check_initiator_node_acl() is not called with
qla_hw->hardware_lock held for all accesses of ->tpg_sess_list, the
code should be using transport_register_session() instead.
iscsi-target: Avoid early conn_logout_comp for iser connections
This patch fixes a iser specific logout bug where early complete()
of conn->conn_logout_comp in iscsit_close_connection() was causing
isert_wait4logout() to complete too soon, triggering a use after
free NULL pointer dereference of iscsi_conn memory.
The complete() was originally added for traditional iscsi-target
when a ISCSI_LOGOUT_OP failed in iscsi_target_rx_opcode(), but given
iser-target does not wait in logout failure, this special case needs
to be avoided.
The original patch was wrong, iscsit_close_connection() still needs
to release iscsi_conn during both normal + exception IN_LOGOUT status
with ib_isert enabled.
The original OOPs is due to completing conn_logout_comp early within
iscsit_close_connection(), causing isert_wait4logout() to complete
instead of waiting for iscsit_logout_post_handler_*() to be called.
target: Disallow changing of WRITE cache/FUA attrs after export
Now that incoming FUA=1 bit check is enforced for backends with FUA or
WCE disabled, go ahead and disallow the changing of related backend
attributes when active fabric exports exist.
This is required to avoid potential failures with existing initiator
LUN registrations that have been previously created with FUA=1.
Reported-by: Christoph Hellwig <hch@lst.de> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: James Bottomley <JBottomley@Parallels.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Linus Torvalds [Thu, 19 Mar 2015 23:43:10 +0000 (16:43 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
"An update to Synaptics driver that makes it usable with the 2015
lineup from Lenovo"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Revert "Input: synaptics - use dmax in input_mt_assign_slots"
Input: synaptics - remove X250 from the topbuttonpad list
Input: synaptics - remove X1 Carbon 3rd gen from the topbuttonpad list
Input: synaptics - re-route tracksticks buttons on the Lenovo 2015 series
Input: synaptics - remove TOPBUTTONPAD property for Lenovos 2015
Input: synaptics - retrieve the extended capabilities in query $10
Input: synaptics - do not retrieve the board id on old firmwares
Input: synaptics - handle spurious release of trackstick buttons
Input: synaptics - fix middle button on Lenovo 2015 products
Input: synaptics - skip quirks when post-2013 dimensions
Input: synaptics - support min/max board id in min_max_pnpid_table
Input: synaptics - remove obsolete min/max quirk for X240
Input: synaptics - query min dimensions for fw v8.1
Input: synaptics - log queried and quirked dimension values
Input: synaptics - split synaptics_resolution(), query first
Linus Torvalds [Thu, 19 Mar 2015 23:27:36 +0000 (16:27 -0700)]
Merge branch 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs fixes from Miklos Szeredi:
"This fixes minor issues with the multi-layer update in v4.0"
* 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: upper fs should not be R/O
ovl: check lowerdir amount for non-upper mount
ovl: print error message for invalid mount options
Linus Torvalds [Thu, 19 Mar 2015 22:52:28 +0000 (15:52 -0700)]
Merge tag 'pinctrl-v4.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control fixes from Linus Walleij:
"Here is a slew of pin control fixes I've accumulated for the v4.0
kernel. Nothing special, just driver fixes (mainly embedded Intel it
seems) and a misunderstanding regarding the stub functions was
reverted:
- Fix up consumer return values on pin control stubs.
- Four patches fixing up the interrupt handling and sleep context
save in the Baytrail driver.
- Make default output directions work properly in the Cherryview
driver.
- Fix interrupt locking in the AT91 driver.
- Fix setting interrupt generating lines as input in the sunxi
driver"
* tag 'pinctrl-v4.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: sun4i: GPIOs configured as irq must be set to input before reading
pinctrl: at91: move lock/unlock_as_irq calls into request/release
pinctrl: update direction_output function of cherryview driver
pinctrl: baytrail: Save pin context over system sleep
pinctrl: baytrail: Rework interrupt handling
pinctrl: baytrail: Clear interrupt triggering from pins that are in GPIO mode
pinctrl: baytrail: Relax GPIO request rules
Revert "pinctrl: consumer: use correct retval for placeholder functions"
projects / mirror_ubuntu-eoan-kernel.git / log