The use of config_enabled() is ambiguous. For config options,
IS_ENABLED(), IS_REACHABLE(), etc. will make intention clearer.
Sometimes config_enabled() has been used for non-config options because
it is useful to check whether the given symbol is defined or not.
I have been tackling on deprecating config_enabled(), and now is the
time to finish this work.
Some new users have appeared for v4.9-rc1, but it is trivial to replace
them:
- arch/x86/mm/kaslr.c
replace config_enabled() with IS_ENABLED() because
CONFIG_X86_ESPFIX64 and CONFIG_EFI are boolean.
- include/asm-generic/export.h
replace config_enabled() with __is_defined().
Then, config_enabled() can be removed now.
Going forward, please use IS_ENABLED(), IS_REACHABLE(), etc. for config
options, and __is_defined() for non-config symbols.
Link: http://lkml.kernel.org/r/1476616078-32252-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bitwise shifts by amounts greater than or equal to the width of the left
operand are undefined. A malicious guest can exploit this to crash a
32-bit host, due to the BUG_ON(1)'s in handle_{invept,invvpid}.
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <1477496318-17681-1-git-send-email-jmattson@google.com>
[Change 1UL to 1, to match the range check on the shift count. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 784d5699ed ("x86: move exports to actual definitions") removed the
EXPORT_SYMBOL(__fentry__) and EXPORT_SYMBOL(mcount) from x8664_ksyms_64.c,
and added EXPORT_SYMBOL(function_hook) in mcount_64.S instead. The problem
is that function_hook isn't a function at all, but a macro that is defined
as either mcount or __fentry__ depending on the support from gcc.
Originally, I thought this was a macro issue, like what __stringify()
is used for. But the problem is a bit deeper. The Makefile.build has
some magic that does post processing of files to create the CRC
bindings. It does some searches for EXPORT_SYMBOL() and because it
finds a macro name and not the actual functions, this causes
function_hook not to be converted into mcount or __fentry__ and they
are missed.
Instead of adding more magic to Makefile.build, just add
EXPORT_SYMBOL() for mcount and __fentry__ where the ifdef is used.
Since this is assembly and not C, it doesn't require being set after
the function is defined.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Borislav Petkov <bp@alien8.de>
Cc: Gabriel C <nix.or.die@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Link: http://lkml.kernel.org/r/20161024150148.4f9d90e4@gandalf.local.home
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A recent change to the mm code in:
87744ab383 mm: fix cache mode tracking in vm_insert_mixed()
started enforcing checking the memory type against the registered list for
amixed pfn insertion mappings. It happens that the drm drivers for a number
of gpus relied on this being broken. Currently the driver only inserted
VRAM mappings into the tracking table when they came from the kernel,
and userspace mappings never landed in the table. This led to a regression
where all the mapping end up as UC instead of WC now.
I've considered a number of solutions but since this needs to be fixed
in fixes and not next, and some of the solutions were going to introduce
overhead that hadn't been there before I didn't consider them viable at
this stage. These mainly concerned hooking into the TTM io reserve APIs,
but these API have a bunch of fast paths I didn't want to unwind to add
this to.
The solution I've decided on is to add a new API like the arch_phys_wc
APIs (these would have worked but wc_del didn't take a range), and
use them from the drivers to add a WC compatible mapping to the table
for all VRAM on those GPUs. This means we can then create userspace
mapping that won't get degraded to UC.
v1.1: use CONFIG_X86_PAT + add some comments in io.h
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: x86@kernel.org
Cc: mcgrof@suse.com
Cc: Dan Williams <dan.j.williams@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
For mostly historical reasons, the x86 oops dump shows the raw stack
values:
...
[registers]
Stack:
ffff880079af7350 ffff880079905400 0000000000000000 ffffc900008f3ae0
ffffffffa0196610 0000000000000001 00010000ffffffff 0000000087654321
0000000000000002 0000000000000000 0000000000000000 0000000000000000
Call Trace:
...
This seems to be an artifact from long ago, and probably isn't needed
anymore. It generally just adds noise to the dump, and it can be
actively harmful because it leaks kernel addresses.
Linus says:
"The stack dump actually goes back to forever, and it used to be
useful back in 1992 or so. But it used to be useful mainly because
stacks were simpler and we didn't have very good call traces anyway. I
definitely remember having used them - I just do not remember having
used them in the last ten+ years.
Of course, it's still true that if you can trigger an oops, you've
likely already lost the security game, but since the stack dump is so
useless, let's aim to just remove it and make games like the above
harder."
This also removes the related 'kstack=' cmdline option and the
'kstack_depth_to_print' sysctl.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e83bd50df52d8fe88e94d2566426ae40d813bf8f.1477405374.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Printing kernel text addresses in stack dumps is of questionable value,
especially now that address randomization is becoming common.
It can be a security issue because it leaks kernel addresses. It also
affects the usefulness of the stack dump. Linus says:
"I actually spend time cleaning up commit messages in logs, because
useless data that isn't actually information (random hex numbers) is
actively detrimental.
It makes commit logs less legible.
It also makes it harder to parse dumps.
It's not useful. That makes it actively bad.
I probably look at more oops reports than most people. I have not
found the hex numbers useful for the last five years, because they are
just randomized crap.
The stack content thing just makes code scroll off the screen etc, for
example."
The only real downside to removing these addresses is that they can be
used to disambiguate duplicate symbol names. However such cases are
rare, and the context of the stack dump should be enough to be able to
figure it out.
There's now a 'faddr2line' script which can be used to convert a
function address to a file name and line:
$ ./scripts/faddr2line ~/k/vmlinux write_sysrq_trigger+0x51/0x60
write_sysrq_trigger+0x51/0x60:
write_sysrq_trigger at drivers/tty/sysrq.c:1098
Or gdb can be used:
$ echo "list *write_sysrq_trigger+0x51" |gdb ~/k/vmlinux |grep "is in"
(gdb) 0xffffffff815b5d83 is in driver_probe_device (/home/jpoimboe/git/linux/drivers/base/dd.c:378).
(But note that when there are duplicate symbol names, gdb will only show
the first symbol it finds. faddr2line is recommended over gdb because
it handles duplicates and it also does function size checking.)
Here's an example of what a stack dump looks like after this change:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: sysrq_handle_crash+0x45/0x80
PGD 36bfa067 [ 29.650644] PUD 7aca3067
Oops: 0002 [#1] PREEMPT SMP
Modules linked in: ...
CPU: 1 PID: 786 Comm: bash Tainted: G E 4.9.0-rc1+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
task: ffff880078582a40 task.stack: ffffc90000ba8000
RIP: 0010:sysrq_handle_crash+0x45/0x80
RSP: 0018:ffffc90000babdc8 EFLAGS: 00010296
RAX: ffff880078582a40 RBX: 0000000000000063 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000292
RBP: ffffc90000babdc8 R08: 0000000b31866061 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000007 R14: ffffffff81ee8680 R15: 0000000000000000
FS: 00007ffb43869700(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007a3e9000 CR4: 00000000001406e0
Stack:
ffffc90000babe00 ffffffff81572d08 ffffffff81572bd5 0000000000000002
0000000000000000 ffff880079606600 00007ffb4386e000 ffffc90000babe20
ffffffff81573201 ffff880036a3fd00 fffffffffffffffb ffffc90000babe40
Call Trace:
__handle_sysrq+0x138/0x220
? __handle_sysrq+0x5/0x220
write_sysrq_trigger+0x51/0x60
proc_reg_write+0x42/0x70
__vfs_write+0x37/0x140
? preempt_count_sub+0xa1/0x100
? __sb_start_write+0xf5/0x210
? vfs_write+0x183/0x1a0
vfs_write+0xb8/0x1a0
SyS_write+0x58/0xc0
entry_SYSCALL_64_fastpath+0x1f/0xc2
RIP: 0033:0x7ffb42f55940
RSP: 002b:00007ffd33bb6b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007ffb42f55940
RDX: 0000000000000002 RSI: 00007ffb4386e000 RDI: 0000000000000001
RBP: 0000000000000011 R08: 00007ffb4321ea40 R09: 00007ffb43869700
R10: 00007ffb43869700 R11: 0000000000000246 R12: 0000000000778a10
R13: 00007ffd33bb5c00 R14: 0000000000000007 R15: 0000000000000010
Code: 34 e8 d0 34 bc ff 48 c7 c2 3b 2b 57 81 be 01 00 00 00 48 c7 c7 e0 dd e5 81 e8 a8 55 ba ff c7 05 0e 3f de 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 e8 4c 49 bc ff 84 c0 75 c3 48 c7
RIP: sysrq_handle_crash+0x45/0x80 RSP: ffffc90000babdc8
CR2: 0000000000000000
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/69329cb29b8f324bb5fcea14d61d224807fb6488.1477405374.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yeah, I know, I know, this is a huuge patch and reviewing it is hard.
Sorry but this is the only way I could think of in which I can rewrite
the microcode patches loading procedure without breaking (knowingly) the
driver.
So maybe this patch is easier to review if one looks at the files after
the patch has been applied instead at the diff. Because then it becomes
pretty obvious:
* The BSP-loading path - load_ucode_bsp() is working independently from
the AP path now and it doesn't save any pointers or patches anymore -
it solely parses the builtin or initrd microcode and applies the patch.
That's it.
This fixes the CONFIG_RANDOMIZE_MEMORY offset fun more solidly.
* The AP-loading path - load_ucode_ap() then goes and scans
builtin/initrd *again* for the microcode patches but it caches them this
time so that we don't have to do that scan on each AP but only once.
This simplifies the code considerably.
Then, when we save the microcode from the initrd/builtin, we go and
add the relevant patches to our own cache. The AMD side did do that
and now the Intel side does it too. So no more pointer copying and
blabla, we save the microcode patches ourselves and are independent from
initrd/builtin.
This whole conversion gives us other benefits like unifying the
initrd parsing into a single function: find_microcode_in_initrd() is
used by both.
The diffstat speaks for itself: 456 insertions(+), 695 deletions(-)
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161025095522.11964-12-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince Waver reported the following bug:
WARNING: CPU: 0 PID: 21338 at arch/x86/mm/fault.c:435 vmalloc_fault+0x58/0x1f0
CPU: 0 PID: 21338 Comm: perf_fuzzer Not tainted 4.8.0+ #37
Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013
Call Trace:
<NMI> ? dump_stack+0x46/0x59
? __warn+0xd5/0xee
? vmalloc_fault+0x58/0x1f0
? __do_page_fault+0x6d/0x48e
? perf_log_throttle+0xa4/0xf4
? trace_page_fault+0x22/0x30
? __unwind_start+0x28/0x42
? perf_callchain_kernel+0x75/0xac
? get_perf_callchain+0x13a/0x1f0
? perf_callchain+0x6a/0x6c
? perf_prepare_sample+0x71/0x2eb
? perf_event_output_forward+0x1a/0x54
? __default_send_IPI_shortcut+0x10/0x2d
? __perf_event_overflow+0xfb/0x167
? x86_pmu_handle_irq+0x113/0x150
? native_read_msr+0x6/0x34
? perf_event_nmi_handler+0x22/0x39
? perf_ibs_nmi_handler+0x4a/0x51
? perf_event_nmi_handler+0x22/0x39
? nmi_handle+0x4d/0xf0
? perf_ibs_handle_irq+0x3d1/0x3d1
? default_do_nmi+0x3c/0xd5
? do_nmi+0x92/0x102
? end_repeat_nmi+0x1a/0x1e
? entry_SYSCALL_64_after_swapgs+0x12/0x4a
? entry_SYSCALL_64_after_swapgs+0x12/0x4a
? entry_SYSCALL_64_after_swapgs+0x12/0x4a
<EOE> ^A4---[ end trace 632723104d47d31a ]---
BUG: stack guard page was hit at ffffc90008500000 (stack is ffffc900084fc000..ffffc900084fffff)
kernel stack overflow (page fault): 0000 [#1] SMP
...
The NMI hit in the entry code right after setting up the stack pointer
from 'cpu_current_top_of_stack', so the kernel stack was empty. The
'guess' version of __unwind_start() attempted to dereference the "top of
stack" pointer, which is not actually *on* the stack.
Add a check in the guess unwinder to deal with an empty stack. (The
frame pointer unwinder already has such a check.)
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 7c7900f897 ("x86/unwind: Add new unwind interface and implementations")
Link: http://lkml.kernel.org/r/20161024133127.e5evgeebdbohnmpb@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull xen fixes from David Vrabel:
- advertise control feature flags in xenstore
- fix x86 build when XEN_PVHVM is disabled
* tag 'for-linus-4.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xenbus: check return value of xenbus_scanf()
xenbus: prefer list_for_each()
x86: xen: move cpu_up functions out of ifdef
xenbus: advertise control feature flags
Three newly introduced functions are not defined when CONFIG_XEN_PVHVM is
disabled, but are still being used:
arch/x86/xen/enlighten.c:141:12: warning: ‘xen_cpu_up_prepare’ used but never defined
arch/x86/xen/enlighten.c:142:12: warning: ‘xen_cpu_up_online’ used but never defined
arch/x86/xen/enlighten.c:143:12: warning: ‘xen_cpu_dead’ used but never defined
Fixes: 4d737042d6 ("xen/x86: Convert to hotplug state machine")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Ondrej reported that IRQs stopped working in v4.7 on several
platforms. A typical scenario, from Ondrej's VT82C694X/694X, is:
ACPI: Using PIC for interrupt routing
ACPI: PCI Interrupt Link [LNKA] (IRQs 1 3 4 5 6 7 10 *11 12 14 15)
ACPI: No IRQ available for PCI Interrupt Link [LNKA]
8139too 0000:00:0f.0: PCI INT A: no GSI
We're using PIC routing, so acpi_irq_balance == 0, and LNKA is already
active at IRQ 11. In that case, acpi_pci_link_allocate() only tries
to use the active IRQ (IRQ 11) which also happens to be the SCI.
We should penalize the SCI by PIRQ_PENALTY_PCI_USING, but
irq_get_trigger_type(11) returns something other than
IRQ_TYPE_LEVEL_LOW, so we penalize it by PIRQ_PENALTY_ISA_ALWAYS
instead, which makes acpi_pci_link_allocate() assume the IRQ isn't
available and give up.
Add acpi_penalize_sci_irq() so platforms can tell us the SCI IRQ,
trigger, and polarity directly and we don't have to depend on
irq_get_trigger_type().
Fixes: 103544d869 (ACPI,PCI,IRQ: reduce resource requirements)
Link: http://lkml.kernel.org/r/201609251512.05657.linux@rainbow-software.org
Reported-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Tested-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Pull x86 fixes from Ingo Molnar:
"Three fixes, a hw-enablement and a cross-arch fix/enablement change:
- SGI/UV fix for older platforms
- x32 signal handling fix
- older x86 platform bootup APIC fix
- AVX512-4VNNIW (Neural Network Instructions) and AVX512-4FMAPS
(Multiply Accumulation Single precision instructions) enablement.
- move thread_info back into x86 specific code, to make life easier
for other architectures trying to make use of
CONFIG_THREAD_INFO_IN_TASK_STRUCT=y"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot/smp: Don't try to poke disabled/non-existent APIC
sched/core, x86: Make struct thread_info arch specific again
x86/signal: Remove bogus user_64bit_mode() check from sigaction_compat_abi()
x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates
x86/cpufeature: Add AVX512_4VNNIW and AVX512_4FMAPS features
x86/vmware: Skip timer_irq_works() check on VMware
kbuild test robot reported this against the -RT tree:
|>> arch/x86/kernel/acpi/boot.c:90:21: warning: 'acpi_ioapic_lock' defined but not used [-Wunused-variable]
| static DEFINE_MUTEX(acpi_ioapic_lock);
| ^
| include/linux/mutex_rt.h:27:15: note: in definition of macro 'DEFINE_MUTEX'
| struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
^~~~~~~~~
which is also true (as in non-used) for !RT but the compiler does not
emit a warning.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161021084449.32523-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
