The function is called by both 32-bit and 64-bit early setup right
after early_init_devtree(). All it does is run yet another early
DT parser which is precisely what early_init_devtree() is about,
so move it in there.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Anything in early_setup() needs to be justified to be there, in
this case, we need the trampolines before we can take exceptions
and thus before we turn on the MMU.
Also remove a pretty meaningless and misplaced debug message
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Fix comment formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
early_init() is called in-place before kernel relocation and using
whatever MMU setup exists at the point the kernel is entered.
machine_init() is called after relocation and after some initial
mapping of PAGE_OFFSET has been established (typically using BATs
on 6xx/7xx/7xxx processors or some form of bolted TLB on others).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is no reason to read the entry/exit control fields of the
VMCS and immediately write back the same value.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Because the vmcs12 preemption timer is emulated through a separate hrtimer,
we can keep on using the preemption timer in the vmcs02 to emulare L1's
TSC deadline timer.
However, the corresponding bit in the pin-based execution control field
must be kept consistent between vmcs01 and vmcs02. On vmentry we copy
it into the vmcs02; on vmexit the preemption timer must be disabled in
the vmcs01 if a preemption timer vmexit happened while in guest mode.
The preemption timer value in the vmcs02 is set by vmx_vcpu_run, so it
need not be considered in prepare_vmcs02.
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Cc: Haozhong Zhang <haozhong.zhang@intel.com>
Tested-by: Wanpeng Li <kernellwp@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The preemption timer for nested VMX is emulated by hrtimer which is started on L2
entry, stopped on L2 exit and evaluated via the check_nested_events hook. However,
nested_vmx_exit_handled is always returning true for preemption timer vmexit. Then,
the L1 preemption timer vmexit is captured and be treated as a L2 preemption
timer vmexit, causing NULL pointer dereferences or worse in the L1 guest's
vmexit handler:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [< (null)>] (null)
PGD 0
Oops: 0010 [#1] SMP
Call Trace:
? kvm_lapic_expired_hv_timer+0x47/0x90 [kvm]
handle_preemption_timer+0xe/0x20 [kvm_intel]
vmx_handle_exit+0x169/0x15a0 [kvm_intel]
? kvm_arch_vcpu_ioctl_run+0xd5d/0x19d0 [kvm]
kvm_arch_vcpu_ioctl_run+0xdee/0x19d0 [kvm]
? kvm_arch_vcpu_ioctl_run+0xd5d/0x19d0 [kvm]
? vcpu_load+0x1c/0x60 [kvm]
? kvm_arch_vcpu_load+0x57/0x260 [kvm]
kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm]
do_vfs_ioctl+0x96/0x6a0
? __fget_light+0x2a/0x90
SyS_ioctl+0x79/0x90
do_syscall_64+0x68/0x180
entry_SYSCALL64_slow_path+0x25/0x25
Code: Bad RIP value.
RIP [< (null)>] (null)
RSP <ffff8800b5263c48>
CR2: 0000000000000000
---[ end trace 9c70c48b1a2bc66e ]---
This can be reproduced readily by preemption timer enabled on L0 and disabled
on L1.
Return false since preemption timer vmexits must never be reflected to L2.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Simplify cpu_has_vmx_preemption_timer. This is consistent with the
rest of setup_vmcs_config and preparatory for the next patch.
Tested-by: Wanpeng Li <kernellwp@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch implements the write_sec callback that handle PL310
secure registers writes.
This callback is just a stub for now, to avoid system crash.
Later, it could handle SMC calls so that TZ handles the needed writes.
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
This string is used by dump_stack and as we now support
more SoC's than just STiH415/6 it is misleading to have
the current string in the stack trace.
This patch updates it to be more generic for the STi
family of SoCs.
So instead of looking like this
[ 271.672555] Hardware name: STiH415/416 SoC with Flattened Device Tree
[ 271.678998] [<c0310490>] (unwind_backtrace) from [<c030bb54>] (show_stack+0x10/0x14)
[ 271.686746] [<c030bb54>] (show_stack) from [<c058bc4c>] (dump_stack+0x98/0xac)
[snip]
it now looks like this:
[ 2.669879] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc3-00026-g38a1ce6-dirty #76
[ 2.677973] Hardware name: STi SoC with Flattened Device Tree
[ 2.683723] [<c0310490>] (unwind_backtrace) from [<c030bb54>] (show_stack+0x10/0x14)
[ 2.691472] [<c030bb54>] (show_stack) from [<c058bc0c>] (dump_stack+0x98/0xac)
[snip]
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Let's drop the last two remaining omap3 legacy boot board files.
Let's only use the device tree based booting known to work for
these two boards.
We still have two omap3 boards booting in legacy mode in addition
to device tree based booting. All the other ten or so omap2+ SoCs
have been booting using device tree mode only for years now. This
has allowed us to get rid of quite a bit of arch/arm/mach-omap2
related platform init code in favor of dts and driver changes.
Pretty much the only remaining known users for omap3 legacy boot
board files are Kevin's and Russell's boot test systems, and N900
kernel tree maintained by Pali and Ivaylo. And all of them are
also supporting the device tree based booting. The legacy booting
mode has been kept around mostly to verify against regressions.
As there is still a slim chance of possible other uses of the
mainline kernel for these boards, let's just drop the board
files for v4.8, and let's not touch the related platform init
code until around v4.9 time if no issues are found. This makes
it trivial for us to add back the board files with a simple revert.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Let's drop the last two remaining omap3 legacy boot board files.
Let's only use the device tree based booting known to work for
these two boards.
We still have two omap3 boards booting in legacy mode in addition
to device tree based booting. All the other ten or so omap2+ SoCs
have been booting using device tree mode only for years now. This
has allowed us to get rid of quite a bit of arch/arm/mach-omap2
related platform init code in favor of dts and driver changes.
Pretty much the only remaining known users for omap3 legacy boot
board files are Kevin's and Russell's boot test systems, and N900
kernel tree maintained by Pali and Ivaylo. And all of them are
also supporting the device tree based booting. The legacy booting
mode has been kept around mostly to verify against regressions.
As there is still a slim chance of possible other uses of the
mainline kernel for these boards, let's just drop the board
files for v4.8, and let's not touch the related platform init
code until around v4.9 time if no issues are found. This makes
it trivial for us to add back the board files with a simple revert.
Acked-By: Sebastian Reichel <sre@kernel.org>
Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
The red led on the Bananapi M1+ is wired to light up as soon as the
board is powered, and continues to be lit while the GPIO is floating.
Rename the LED to "pwr", remove the default trigger, and mark it as
default on.
Also fix the pinmux node that was specifying a different pin for this
LED.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The dts file uses "bananapi" for some labels and "bananapim1plus" for
other. Use the shortened "bpi_m1p" suffix for all board specific labels.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The bananapi-m1-plus dts file was indented using 4 spaces, without
tabs. This does not match the code style.
Reindent the whole file before we do anything else.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Lamobo R1 has a headphone jack for audio output, and an onboard
microphone. These are tied to the SoC's internal audio codec.
Enable the audio codec.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
reg_ahci_5v uses a GPIO in active high mode. Use the proper macro,
instead of just 0 for the GPIO flags.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Enable more drivers for IP blocks for existing Exynos7 and upcoming
Exynos5433:
1. SPI,
2. Watchdog,
3. USB: DWC3, Exynos EHCI and OHCI,
4. Exynos ADC,
5. Samsung PWM.
These are already used by Exynos7 Espresso board or will be used by
Exynos5433 based board.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
This reverts commit 2c95afc1e8.
Stephane reported the following regression:
> Since Andi added:
>
> commit 2c95afc1e8
> Author: Andi Kleen <ak@linux.intel.com>
> Date: Thu Jun 9 06:14:38 2016 -0700
>
> perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86
>
> $ perf stat -e ref-cycles ls
> <not counted> ....
>
> fails systematically because the ref-cycles is now used by the
> watchdog and given this is a system-wide pinned event, it monopolizes
> the fixed counter 2 which is the only counter able to measure this event.
Since the next merge window is near, fix the regression for now
by reverting the commit.
Reported-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The EFI firmware on Macs contains a full-fledged network stack for
downloading OS X images from osrecovery.apple.com. Unfortunately
on Macs introduced 2011 and 2012, EFI brings up the Broadcom 4331
wireless card on every boot and leaves it enabled even after
ExitBootServices has been called. The card continues to assert its IRQ
line, causing spurious interrupts if the IRQ is shared. It also corrupts
memory by DMAing received packets, allowing for remote code execution
over the air. This only stops when a driver is loaded for the wireless
card, which may be never if the driver is not installed or blacklisted.
The issue seems to be constrained to the Broadcom 4331. Chris Milsted
has verified that the newer Broadcom 4360 built into the MacBookPro11,3
(2013/2014) does not exhibit this behaviour. The chances that Apple will
ever supply a firmware fix for the older machines appear to be zero.
The solution is to reset the card on boot by writing to a reset bit in
its mmio space. This must be done as an early quirk and not as a plain
vanilla PCI quirk to successfully combat memory corruption by DMAed
packets: Matthew Garrett found out in 2012 that the packets are written
to EfiBootServicesData memory (http://mjg59.dreamwidth.org/11235.html).
This type of memory is made available to the page allocator by
efi_free_boot_services(). Plain vanilla PCI quirks run much later, in
subsys initcall level. In-between a time window would be open for memory
corruption. Random crashes occurring in this time window and attributed
to DMAed packets have indeed been observed in the wild by Chris
Bainbridge.
When Matthew Garrett analyzed the memory corruption issue in 2012, he
sought to fix it with a grub quirk which transitions the card to D3hot:
http://git.savannah.gnu.org/cgit/grub.git/commit/?id=9d34bb85da56
This approach does not help users with other bootloaders and while it
may prevent DMAed packets, it does not cure the spurious interrupts
emanating from the card. Unfortunately the card's mmio space is
inaccessible in D3hot, so to reset it, we have to undo the effect of
Matthew's grub patch and transition the card back to D0.
Note that the quirk takes a few shortcuts to reduce the amount of code:
The size of BAR 0 and the location of the PM capability is identical
on all affected machines and therefore hardcoded. Only the address of
BAR 0 differs between models. Also, it is assumed that the BCMA core
currently mapped is the 802.11 core. The EFI driver seems to always take
care of this.
Michael Büsch, Bjorn Helgaas and Matt Fleming contributed feedback
towards finding the best solution to this problem.
The following should be a comprehensive list of affected models:
iMac13,1 2012 21.5" [Root Port 00:1c.3 = 8086:1e16]
iMac13,2 2012 27" [Root Port 00:1c.3 = 8086:1e16]
Macmini5,1 2011 i5 2.3 GHz [Root Port 00:1c.1 = 8086:1c12]
Macmini5,2 2011 i5 2.5 GHz [Root Port 00:1c.1 = 8086:1c12]
Macmini5,3 2011 i7 2.0 GHz [Root Port 00:1c.1 = 8086:1c12]
Macmini6,1 2012 i5 2.5 GHz [Root Port 00:1c.1 = 8086:1e12]
Macmini6,2 2012 i7 2.3 GHz [Root Port 00:1c.1 = 8086:1e12]
MacBookPro8,1 2011 13" [Root Port 00:1c.1 = 8086:1c12]
MacBookPro8,2 2011 15" [Root Port 00:1c.1 = 8086:1c12]
MacBookPro8,3 2011 17" [Root Port 00:1c.1 = 8086:1c12]
MacBookPro9,1 2012 15" [Root Port 00:1c.1 = 8086:1e12]
MacBookPro9,2 2012 13" [Root Port 00:1c.1 = 8086:1e12]
MacBookPro10,1 2012 15" [Root Port 00:1c.1 = 8086:1e12]
MacBookPro10,2 2012 13" [Root Port 00:1c.1 = 8086:1e12]
For posterity, spurious interrupts caused by the Broadcom 4331 wireless
card resulted in splats like this (stacktrace omitted):
irq 17: nobody cared (try booting with the "irqpoll" option)
handlers:
[<ffffffff81374370>] pcie_isr
[<ffffffffc0704550>] sdhci_irq [sdhci] threaded [<ffffffffc07013c0>] sdhci_thread_irq [sdhci]
[<ffffffffc0a0b960>] azx_interrupt [snd_hda_codec]
Disabling IRQ #17
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79301
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111781
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=728916
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=895951#c16
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1009819
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1098621
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1149632#c5
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1279130
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1332732
Tested-by: Konstantin Simanov <k.simanov@stlk.ru> # [MacBookPro8,1]
Tested-by: Lukas Wunner <lukas@wunner.de> # [MacBookPro9,1]
Tested-by: Bryan Paradis <bryan.paradis@gmail.com> # [MacBookPro9,2]
Tested-by: Andrew Worsley <amworsley@gmail.com> # [MacBookPro10,1]
Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com> # [MacBookPro10,2]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris Milsted <cmilsted@redhat.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: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Michael Buesch <m@bues.ch>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: b43-dev@lists.infradead.org
Cc: linux-pci@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: stable@vger.kernel.org
Cc: stable@vger.kernel.org # 123456789abc: x86/quirks: Apply nvidia_bugs quirk only on root bus
Cc: stable@vger.kernel.org # 123456789abc: x86/quirks: Reintroduce scanning of secondary buses
Link: http://lkml.kernel.org/r/48d0972ac82a53d460e5fce77a07b2560db95203.1465690253.git.lukas@wunner.de
[ Did minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We used to scan secondary buses until the following commit that
was applied in 2009:
8659c406ad ("x86: only scan the root bus in early PCI quirks")
which commit constrained early quirks to the root bus only. Its
motivation was to prevent application of the nvidia_bugs quirk
on secondary buses.
We're about to add a quirk to reset the Broadcom 4331 wireless card on
2011/2012 Macs, which is located on a secondary bus behind a PCIe root
port. To facilitate that, reintroduce scanning of secondary buses.
The commit message of 8659c406ad notes that scanning only the root bus
"saves quite some unnecessary scanning work". The algorithm used prior
to 8659c406ad was particularly time consuming because it scanned
buses 0 to 31 brute force. To avoid lengthening boot time, employ a
recursive strategy which only scans buses that are actually reachable
from the root bus.
Yinghai Lu pointed out that the secondary bus number read from a
bridge's config space may be invalid, in particular a value of 0 would
cause an infinite loop. The PCI core goes beyond that and recurses to a
child bus only if its bus number is greater than the parent bus number
(see pci_scan_bridge()). Since the root bus is numbered 0, this implies
that secondary buses may not be 0. Do the same on early scanning.
If this algorithm is found to significantly impact boot time or cause
infinite loops on broken hardware, it would be possible to limit its
recursion depth: The Broadcom 4331 quirk applies at depth 1, all others
at depth 0, so the bus need not be scanned deeper than that for now. An
alternative approach would be to revert to scanning only the root bus,
and apply the Broadcom 4331 quirk to the root ports 8086:1c12, 8086:1e12
and 8086:1e16. Apple always positioned the card behind either of these
three ports. The quirk would then check presence of the card in slot 0
below the root port and do its deed.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
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>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/f0daa70dac1a9b2483abdb31887173eb6ab77bdf.1465690253.git.lukas@wunner.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull MIPS fix from Ralf Baechle:
"Another week with just a single 4.7 fix.
This fixes a possible 'loss' of the huge page bit from pmd on
permission change"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Fix page table corruption on THP permission changes.
The new physical address randomized KASLR implementation can cause the
kernel to be aligned close to the end of physical memory. In this case,
_brk_end aligned to PMD will go beyond what is expected safe and hit
the assert in __phys_addr_symbol():
VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
Instead, perform an inclusive range check to avoid incorrectly triggering
the assert:
kernel BUG at arch/x86/mm/physaddr.c:38!
invalid opcode: 0000 [#1] SMP
...
RIP: 0010:[<ffffffffbe055721>] __phys_addr_symbol+0x41/0x50
...
Call Trace:
[<ffffffffbe052eb9>] cpa_process_alias+0xa9/0x210
[<ffffffffbe109011>] ? do_raw_spin_unlock+0xc1/0x100
[<ffffffffbe051eef>] __change_page_attr_set_clr+0x8cf/0xbd0
[<ffffffffbe201a4d>] ? vm_unmap_aliases+0x7d/0x210
[<ffffffffbe05237c>] change_page_attr_set_clr+0x18c/0x4e0
[<ffffffffbe0534ec>] set_memory_4k+0x2c/0x40
[<ffffffffbefb08b3>] check_bugs+0x28/0x2a
[<ffffffffbefa4f52>] start_kernel+0x49d/0x4b9
[<ffffffffbefa4120>] ? early_idt_handler_array+0x120/0x120
[<ffffffffbefa4423>] x86_64_start_reservations+0x29/0x2b
[<ffffffffbefa4568>] x86_64_start_kernel+0x143/0x152
Signed-off-by: Thomas Garnier <thgarnie@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Link: http://lkml.kernel.org/r/20160615190545.GA26071@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Thanks to all the work that was done by Andy Lutomirski and others,
enter_from_user_mode() and prepare_exit_to_usermode() are now called only with
interrupts disabled. Let's provide them a version of user_enter()/user_exit()
that skips saving and restoring the interrupt flag.
On an AMD-based machine I tested this patch on, with force-enabled
context tracking, the speed-up in system calls was 90 clock cycles or 6%,
measured with the following simple benchmark:
#include <sys/signal.h>
#include <time.h>
#include <unistd.h>
#include <stdio.h>
unsigned long rdtsc()
{
unsigned long result;
asm volatile("rdtsc; shl $32, %%rdx; mov %%eax, %%eax\n"
"or %%rdx, %%rax" : "=a" (result) : : "rdx");
return result;
}
int main()
{
unsigned long tsc1, tsc2;
int pid = getpid();
int i;
tsc1 = rdtsc();
for (i = 0; i < 100000000; i++)
kill(pid, SIGWINCH);
tsc2 = rdtsc();
printf("%ld\n", tsc2 - tsc1);
}
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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>
Cc: kvm@vger.kernel.org
Link: http://lkml.kernel.org/r/1466434712-31440-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The asm-offsets mechanism generates signed numbers, even if the
input value is explicitly unsigned. This causes a problem with
older binutils (e.g. 2.23), which sign-extend a negative number
when @h is applied. Thus, this instruction:
cmpli cr0, r11, VIRT_IMMR_BASE@h
resulted in this:
Error: operand out of range (0xfffffff0 is not between 0x00000000 and
0x0000ffff)
By casting to a larger type, we can force the output to be expressed
as a positive number.
Signed-off-by: Scott Wood <oss@buserror.net>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
