So the SYSENTER instruction is pretty quirky and it has different behavior
depending on bitness and CPU maker.
Yet we create a false sense of coherency by naming it 'ia32_sysenter_target'
in both of the cases.
Split the name into its two uses:
ia32_sysenter_target (32) -> entry_SYSENTER_32
ia32_sysenter_target (64) -> entry_SYSENTER_compat
As per the generic naming scheme for x86 system call entry points:
entry_MNEMONIC_qualifier
where 'qualifier' is one of _32, _64 or _compat.
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rename the following system call entry points:
ia32_cstar_target -> entry_SYSCALL_compat
ia32_syscall -> entry_INT80_compat
The generic naming scheme for x86 system call entry points is:
entry_MNEMONIC_qualifier
where 'qualifier' is one of _32, _64 or _compat.
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The vsyscall code is entry code too, so move it to arch/x86/entry/vsyscall/.
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Create a new directory hierarchy for the low level x86 entry code:
arch/x86/entry/*
This will host all the low level glue that is currently scattered
all across arch/x86/.
Start with entry_64.S and entry_32.S.
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
retint_kernel doesn't require %rcx to be pointing to thread info
(anymore?), and the code on the two alternative paths is - not
really surprisingly - identical.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/556C664F020000780007FB64@mail.emea.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
So the dwarf2 annotations in low level assembly code have
become an increasing hindrance: unreadable, messy macros
mixed into some of the most security sensitive code paths
of the Linux kernel.
These debug info annotations don't even buy the upstream
kernel anything: dwarf driven stack unwinding has caused
problems in the past so it's out of tree, and the upstream
kernel only uses the much more robust framepointers based
stack unwinding method.
In addition to that there's a steady, slow bitrot going
on with these annotations, requiring frequent fixups.
There's no tooling and no functionality upstream that
keeps it correct.
So burn down the sick forest, allowing new, healthier growth:
27 files changed, 350 insertions(+), 1101 deletions(-)
Someone who has the willingness and time to do this
properly can attempt to reintroduce dwarf debuginfo in x86
assembly code plus dwarf unwinding from first principles,
with the following conditions:
- it should be maximally readable, and maximally low-key to
'ordinary' code reading and maintenance.
- find a build time method to insert dwarf annotations
automatically in the most common cases, for pop/push
instructions that manipulate the stack pointer. This could
be done for example via a preprocessing step that just
looks for common patterns - plus special annotations for
the few cases where we want to depart from the default.
We have hundreds of CFI annotations, so automating most of
that makes sense.
- it should come with build tooling checks that ensure that
CFI annotations are sensible. We've seen such efforts from
the framepointer side, and there's no reason it couldn't be
done on the dwarf side.
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: Frédéric Weisbecker <fweisbec@gmail.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.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: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The early_idt_handlers asm code generates an array of entry
points spaced nine bytes apart. It's not really clear from that
code or from the places that reference it what's going on, and
the code only works in the first place because GAS never
generates two-byte JMP instructions when jumping to global
labels.
Clean up the code to generate the correct array stride (member size)
explicitly. This should be considerably more robust against
screw-ups, as GAS will warn if a .fill directive has a negative
count. Using '. =' to advance would have been even more robust
(it would generate an actual error if it tried to move
backwards), but it would pad with nulls, confusing anyone who
tries to disassemble the code. The new scheme should be much
clearer to future readers.
While we're at it, improve the comments and rename the array and
common code.
Binutils may start relaxing jumps to non-weak labels. If so,
this change will fix our build, and we may need to backport this
change.
Before, on x86_64:
0000000000000000 <early_idt_handlers>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 00 00 00 00 jmpq 9 <early_idt_handlers+0x9>
5: R_X86_64_PC32 early_idt_handler-0x4
...
48: 66 90 xchg %ax,%ax
4a: 6a 08 pushq $0x8
4c: e9 00 00 00 00 jmpq 51 <early_idt_handlers+0x51>
4d: R_X86_64_PC32 early_idt_handler-0x4
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: e9 00 00 00 00 jmpq 120 <early_idt_handler>
11c: R_X86_64_PC32 early_idt_handler-0x4
After:
0000000000000000 <early_idt_handler_array>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 14 01 00 00 jmpq 11d <early_idt_handler_common>
...
48: 6a 08 pushq $0x8
4a: e9 d1 00 00 00 jmpq 120 <early_idt_handler_common>
4f: cc int3
50: cc int3
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: eb 03 jmp 120 <early_idt_handler_common>
11d: cc int3
11e: cc int3
11f: cc int3
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Binutils <binutils@sourceware.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Jan Beulich <JBeulich@suse.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/ac027962af343b0c599cbfcf50b945ad2ef3d7a8.1432336324.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The "movw %ds,%cx" instruction needs a 0x66 prefix, while
"movl %ds,%ecx" does not.
The difference is that latter form (on 64-bit CPUs)
overwrites the entire %ecx, not only its lower half.
But subsequent code doesn't depend on the value of upper
half of %ecx, so we can safely use the shorter instruction.
The new code is also faster than the old one - now we don't
depend on the old value of %ecx, but this code fragment is
not performance-critical so it does not matter much.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1431722346-26585-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since the ISA irqs are in a single block, use
ISA_IRQ_VECTOR(irq) instead of individual macros.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431185813-15413-5-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use IA32_SYSCALL_VECTOR for both compat and native.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431185813-15413-4-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
32-bit code has PER_CPU_VAR(cpu_current_top_of_stack).
64-bit code uses somewhat more obscure: PER_CPU_VAR(cpu_tss + TSS_sp0).
Define the 'cpu_current_top_of_stack' macro on CONFIG_X86_64
as well so that the PER_CPU_VAR(cpu_current_top_of_stack)
expression can be used in both 32-bit and 64-bit code.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1429889495-27850-3-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
PER_CPU_VAR(kernel_stack) is redundant:
- On the 64-bit build, we can use PER_CPU_VAR(cpu_tss + TSS_sp0).
- On the 32-bit build, we can use PER_CPU_VAR(cpu_current_top_of_stack).
PER_CPU_VAR(kernel_stack) will be deleted by a separate change.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1429889495-27850-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
iTLB-load-misses and LLC-load-misses count incorrectly on SLM.
There is no ITLB.MISSES support on SLM. Event PAGE_WALKS.I_SIDE_WALK
should be used to count iTLB-load-misses. This event counts when an
instruction (I) page walk is completed or started. Since a page walk
implies a TLB miss, the number of TLB misses can be counted by counting
the number of pagewalks.
DMND_DATA_RD counts both demand and DCU prefetch data reads. However,
LLC-load-misses should only count demand reads. There is no way to not
include prefetches with a single counter on SLM. So the LLC-load-misses
support should be removed on SLM.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1429608881-5055-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Fix blkback regression if using persistent grants.
- Fix various event channel related suspend/resume bugs.
- Fix AMD x86 regression with X86_BUG_SYSRET_SS_ATTRS.
- SWIOTLB on ARM now uses frames <4 GiB (if available) so device only
capable of 32-bit DMA work.
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Merge tag 'for-linus-4.1b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen bug fixes from David Vrabel:
- fix blkback regression if using persistent grants
- fix various event channel related suspend/resume bugs
- fix AMD x86 regression with X86_BUG_SYSRET_SS_ATTRS
- SWIOTLB on ARM now uses frames <4 GiB (if available) so device only
capable of 32-bit DMA work.
* tag 'for-linus-4.1b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARM
hypervisor/x86/xen: Unset X86_BUG_SYSRET_SS_ATTRS on Xen PV guests
xen/events: Set irq_info->evtchn before binding the channel to CPU in __startup_pirq()
xen/console: Update console event channel on resume
xen/xenbus: Update xenbus event channel on resume
xen/events: Clear cpu_evtchn_mask before resuming
xen-pciback: Add name prefix to global 'permissive' variable
xen: Suspend ticks on all CPUs during suspend
xen/grant: introduce func gnttab_unmap_refs_sync()
xen/blkback: safely unmap purge persistent grants
Pull x86 fixes from Ingo Molnar:
"EFI fixes, and FPU fix, a ticket spinlock boundary condition fix and
two build fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Always restore_xinit_state() when use_eager_cpu()
x86: Make cpu_tss available to external modules
efi: Fix error handling in add_sysfs_runtime_map_entry()
x86/spinlocks: Fix regression in spinlock contention detection
x86/mm: Clean up types in xlate_dev_mem_ptr()
x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptr
efivarfs: Ensure VariableName is NUL-terminated
Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, but also an uncore PMU driver fix and an uncore
PMU driver hardware-enablement addition"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf probe: Fix segfault if passed with ''.
perf report: Fix -T/--threads option to work again
perf bench numa: Fix immediate meeting of convergence condition
perf bench numa: Fixes of --quiet argument
perf bench futex: Fix hung wakeup tasks after requeueing
perf probe: Fix bug with global variables handling
perf top: Fix a segfault when kernel map is restricted.
tools lib traceevent: Fix build failure on 32-bit arch
perf kmem: Fix compiles on RHEL6/OL6
tools lib api: Undefine _FORTIFY_SOURCE before setting it
perf kmem: Consistently use PRIu64 for printing u64 values
perf trace: Disable events and drain events when forked workload ends
perf trace: Enable events when doing system wide tracing and starting a workload
perf/x86/intel/uncore: Move PCI IDs for IMC to uncore driver
perf/x86/intel/uncore: Add support for Intel Haswell ULT (lower power Mobile Processor) IMC uncore PMUs
perf/x86/intel: Add cpu_(prepare|starting|dying) for core_pmu
The following commit:
f893959b08 ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()")
removed drop_init_fpu() usage from flush_thread(). This seems to break
things for me - the Go 1.4 test suite fails all over the place with
floating point comparision errors (offending commit found through
bisection).
The functional change was that flush_thread() after this commit
only calls restore_init_xstate() when both use_eager_fpu() and
!used_math() are true. drop_init_fpu() (now fpu_reset_state()) calls
restore_init_xstate() regardless of whether current used_math() - apply
the same logic here.
Switch used_math() -> tsk_used_math(tsk) to consistently use the grabbed
tsk instead of current, like in the rest of flush_thread().
Tested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Bobby Powers <bobbypowers@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pekka Riikonen <priikone@iki.fi>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f893959b ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()")
Link: http://lkml.kernel.org/r/1430147441-9820-1-git-send-email-bobbypowers@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 75182b1632 ("x86/asm/entry: Switch all C consumers of
kernel_stack to this_cpu_sp0()") changed current_thread_info
to use this_cpu_sp0, and indirectly made it rely on init_tss
which was exported with EXPORT_PER_CPU_SYMBOL_GPL.
As a result some macros and inline functions such as set/get_fs,
test_thread_flag and variants have been made unusable for
external modules.
Make cpu_tss exported with EXPORT_PER_CPU_SYMBOL so that these
functions are accessible again, as they were previously.
Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/1430763404-21221-1-git-send-email-marc.dionne@your-file-system.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit 61f01dd941 ("x86_64, asm: Work around AMD SYSRET SS descriptor
attribute issue") makes AMD processors set SS to __KERNEL_DS in
__switch_to() to deal with cases when SS is NULL.
This breaks Xen PV guests who do not want to load SS with__KERNEL_DS.
Since the problem that the commit is trying to address would have to be
fixed in the hypervisor (if it in fact exists under Xen) there is no
reason to set X86_BUG_SYSRET_SS_ATTRS flag for PV VPCUs here.
This can be easily achieved by adding x86_hyper_xen_hvm.set_cpu_features
op which will clear this flag. (And since this structure is no longer
HVM-specific we should do some renaming).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This reverts commits 0a4e6be9ca
and 80f7fdb1c7.
The task migration notifier was originally introduced in order to support
the pvclock vsyscall with non-synchronized TSC, but KVM only supports it
with synchronized TSC. Hence, on KVM the race condition is only needed
due to a bad implementation on the host side, and even then it's so rare
that it's mostly theoretical.
As far as KVM is concerned it's possible to fix the host, avoiding the
additional complexity in the vDSO and the (re)introduction of the task
migration notifier.
Xen, on the other hand, hasn't yet implemented vsyscall support at
all, so we do not care about its plans for non-synchronized TSC.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AMD CPUs don't reinitialize the SS descriptor on SYSRET, so SYSRET with
SS == 0 results in an invalid usermode state in which SS is apparently
equal to __USER_DS but causes #SS if used.
Work around the issue by setting SS to __KERNEL_DS __switch_to, thus
ensuring that SYSRET never happens with SS set to NULL.
This was exposed by a recent vDSO cleanup.
Fixes: e7d6eefaaa x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This series introduces preliminary ACPI 5.1 support to the arm64 kernel
using the "hardware reduced" profile. We don't support any peripherals
yet, so it's fairly limited in scope:
- Memory init (UEFI)
- ACPI discovery (RSDP via UEFI)
- CPU init (FADT)
- GIC init (MADT)
- SMP boot (MADT + PSCI)
- ACPI Kconfig options (dependent on EXPERT)
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull initial ACPI support for arm64 from Will Deacon:
"This series introduces preliminary ACPI 5.1 support to the arm64
kernel using the "hardware reduced" profile. We don't support any
peripherals yet, so it's fairly limited in scope:
- MEMORY init (UEFI)
- ACPI discovery (RSDP via UEFI)
- CPU init (FADT)
- GIC init (MADT)
- SMP boot (MADT + PSCI)
- ACPI Kconfig options (dependent on EXPERT)
ACPI for arm64 has been in development for a while now and hardware
has been available that can boot with either FDT or ACPI tables. This
has been made possible by both changes to the ACPI spec to cater for
ARM-based machines (known as "hardware-reduced" in ACPI parlance) but
also a Linaro-driven effort to get this supported on top of the Linux
kernel. This pull request is the result of that work.
These changes allow us to initialise the CPUs, interrupt controller,
and timers via ACPI tables, with memory information and cmdline coming
from EFI. We don't support a hybrid ACPI/FDT scheme. Of course,
there is still plenty of work to do (a serial console would be nice!)
but I expect that to happen on a per-driver basis after this core
series has been merged.
Anyway, the diff stat here is fairly horrible, but splitting this up
and merging it via all the different subsystems would have been
extremely painful. Instead, we've got all the relevant Acks in place
and I've not seen anything other than trivial (Kconfig) conflicts in
-next (for completeness, I've included my resolution below). Nearly
half of the insertions fall under Documentation/.
So, we'll see how this goes. Right now, it all depends on EXPERT and
I fully expect people to use FDT by default for the immediate future"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (31 commits)
ARM64 / ACPI: make acpi_map_gic_cpu_interface() as void function
ARM64 / ACPI: Ignore the return error value of acpi_map_gic_cpu_interface()
ARM64 / ACPI: fix usage of acpi_map_gic_cpu_interface
ARM64: kernel: acpi: honour acpi=force command line parameter
ARM64: kernel: acpi: refactor ACPI tables init and checks
ARM64: kernel: psci: let ACPI probe PSCI version
ARM64: kernel: psci: factor out probe function
ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer
ARM64 / ACPI: Don't unflatten device tree if acpi=force is passed
ARM64 / ACPI: additions of ACPI documentation for arm64
Documentation: ACPI for ARM64
ARM64 / ACPI: Enable ARM64 in Kconfig
XEN / ACPI: Make XEN ACPI depend on X86
ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64
clocksource / arch_timer: Parse GTDT to initialize arch timer
irqchip: Add GICv2 specific ACPI boot support
ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi
ACPI / processor: Make it possible to get CPU hardware ID via GICC
ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID
ARM64 / ACPI: Parse MADT for SMP initialization
...
This change makes the check exact (no more false positives
on "negative" addresses).
Andy explains:
"Canonical addresses either start with 17 zeros or 17 ones.
In the old code, we checked that the top (64-47) = 17 bits were all
zero. We did this by shifting right by 47 bits and making sure that
nothing was left.
In the new code, we're shifting left by (64 - 48) = 16 bits and then
signed shifting right by the same amount, this propagating the 17th
highest bit to all positions to its left. If we get the same value we
started with, then we're good to go."
While it isn't really important to be fully correct here -
almost all addresses we'll ever see will be userspace ones,
but OTOH it looks to be cheap enough: the new code uses
two more ALU ops but preserves %rcx, allowing to not
reload it from pt_regs->cx again.
On disassembly level, the changes are:
cmp %rcx,0x80(%rsp) -> mov 0x80(%rsp),%r11; cmp %rcx,%r11
shr $0x2f,%rcx -> shl $0x10,%rcx; sar $0x10,%rcx; cmp %rcx,%r11
mov 0x58(%rsp),%rcx -> (eliminated)
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
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: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1429633649-20169-1-git-send-email-dvlasenk@redhat.com
[ Changelog massage. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This keeps all the related PCI IDs together in the driver where
they are used.
Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1429644791-25724-1-git-send-email-sonnyrao@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This uncore is the same as the Haswell desktop part but uses a
different PCI ID.
Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1429569247-16697-1-git-send-email-sonnyrao@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The core_pmu does not define cpu_* callbacks, which handles
allocation of 'struct cpu_hw_events::shared_regs' data,
initialization of debug store and PMU_FL_EXCL_CNTRS counters.
While this probably won't happen on bare metal, virtual CPU can
define x86_pmu.extra_regs together with PMU version 1 and thus
be using core_pmu -> using shared_regs data without it being
allocated. That could could leave to following panic:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8152cd4f>] _spin_lock_irqsave+0x1f/0x40
SNIP
[<ffffffff81024bd9>] __intel_shared_reg_get_constraints+0x69/0x1e0
[<ffffffff81024deb>] intel_get_event_constraints+0x9b/0x180
[<ffffffff8101e815>] x86_schedule_events+0x75/0x1d0
[<ffffffff810586dc>] ? check_preempt_curr+0x7c/0x90
[<ffffffff810649fe>] ? try_to_wake_up+0x24e/0x3e0
[<ffffffff81064ba2>] ? default_wake_function+0x12/0x20
[<ffffffff8109eb16>] ? autoremove_wake_function+0x16/0x40
[<ffffffff810577e9>] ? __wake_up_common+0x59/0x90
[<ffffffff811a9517>] ? __d_lookup+0xa7/0x150
[<ffffffff8119db5f>] ? do_lookup+0x9f/0x230
[<ffffffff811a993a>] ? dput+0x9a/0x150
[<ffffffff8119c8f5>] ? path_to_nameidata+0x25/0x60
[<ffffffff8119e90a>] ? __link_path_walk+0x7da/0x1000
[<ffffffff8101d8f9>] ? x86_pmu_add+0xb9/0x170
[<ffffffff8101d7a7>] x86_pmu_commit_txn+0x67/0xc0
[<ffffffff811b07b0>] ? mntput_no_expire+0x30/0x110
[<ffffffff8119c731>] ? path_put+0x31/0x40
[<ffffffff8107c297>] ? current_fs_time+0x27/0x30
[<ffffffff8117d170>] ? mem_cgroup_get_reclaim_stat_from_page+0x20/0x70
[<ffffffff8111b7aa>] group_sched_in+0x13a/0x170
[<ffffffff81014a29>] ? sched_clock+0x9/0x10
[<ffffffff8111bac8>] ctx_sched_in+0x2e8/0x330
[<ffffffff8111bb7b>] perf_event_sched_in+0x6b/0xb0
[<ffffffff8111bc36>] perf_event_context_sched_in+0x76/0xc0
[<ffffffff8111eb3b>] perf_event_comm+0x1bb/0x2e0
[<ffffffff81195ee9>] set_task_comm+0x69/0x80
[<ffffffff81195fe1>] setup_new_exec+0xe1/0x2e0
[<ffffffff811ea68e>] load_elf_binary+0x3ce/0x1ab0
Adding cpu_(prepare|starting|dying) for core_pmu to have
shared_regs data allocated for core_pmu. AFAICS there's no harm
to initialize debug store and PMU_FL_EXCL_CNTRS either for
core_pmu.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20150421152623.GC13169@krava.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We don't use irq_enable_sysexit on 64-bit kernels any more.
Remove all the paravirt and Xen machinery to support it on
64-bit kernels.
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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/8a03355698fe5b94194e9e7360f19f91c1b2cf1f.1428100853.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Here's the big tty/serial driver update for 4.1-rc1.
It was delayed for a bit due to some questions surrounding some of the
console command line parsing changes that are in here. There's still
one tiny regression for people who were previously putting multiple
console command lines and expecting them all to be ignored for some odd
reason, but Peter is working on fixing that. If not, I'll send a revert
for the offending patch, but I have faith that Peter can address it.
Other than the console work here, there's the usual serial driver
updates and changes, and a buch of 8250 reworks to try to make that
driver easier to maintain over time, and have it support more devices in
the future.
All of these have been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH:
"Here's the big tty/serial driver update for 4.1-rc1.
It was delayed for a bit due to some questions surrounding some of the
console command line parsing changes that are in here. There's still
one tiny regression for people who were previously putting multiple
console command lines and expecting them all to be ignored for some
odd reason, but Peter is working on fixing that. If not, I'll send a
revert for the offending patch, but I have faith that Peter can
address it.
Other than the console work here, there's the usual serial driver
updates and changes, and a buch of 8250 reworks to try to make that
driver easier to maintain over time, and have it support more devices
in the future.
All of these have been in linux-next for a while"
* tag 'tty-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (119 commits)
n_gsm: Drop unneeded cast on netdev_priv
sc16is7xx: expose RTS inversion in RS-485 mode
serial: 8250_pci: port failed after wakeup from S3
earlycon: 8250: Document kernel command line options
earlycon: 8250: Fix command line regression
earlycon: Fix __earlycon_table stride
tty: clean up the tty time logic a bit
serial: 8250_dw: only get the clock rate in one place
serial: 8250_dw: remove useless ACPI ID check
dmaengine: hsu: move memory allocation to GFP_NOWAIT
dmaengine: hsu: remove redundant pieces of code
serial: 8250_pci: add Intel Tangier support
dmaengine: hsu: add Intel Tangier PCI ID
serial: 8250_pci: replace switch-case by formula for Intel MID
serial: 8250_pci: replace switch-case by formula
tty: cpm_uart: replace CONFIG_8xx by CONFIG_CPM1
serial: jsm: some off by one bugs
serial: xuartps: Fix check in console_setup().
serial: xuartps: Get rid of register access macros.
serial: xuartps: Fix iobase use.
...
functions, prompted by their mis-use in staging.
With these function removed, all cpu functions should only iterate to
nr_cpu_ids, so we finally only allocate that many bits when cpumasks
are allocated offstack.
Thanks,
Rusty.
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Merge tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull final removal of deprecated cpus_* cpumask functions from Rusty Russell:
"This is the final removal (after several years!) of the obsolete
cpus_* functions, prompted by their mis-use in staging.
With these function removed, all cpu functions should only iterate to
nr_cpu_ids, so we finally only allocate that many bits when cpumasks
are allocated offstack"
* tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (25 commits)
cpumask: remove __first_cpu / __next_cpu
cpumask: resurrect CPU_MASK_CPU0
linux/cpumask.h: add typechecking to cpumask_test_cpu
cpumask: only allocate nr_cpumask_bits.
Fix weird uses of num_online_cpus().
cpumask: remove deprecated functions.
mips: fix obsolete cpumask_of_cpu usage.
x86: fix more deprecated cpu function usage.
ia64: remove deprecated cpus_ usage.
powerpc: fix deprecated CPU_MASK_CPU0 usage.
CPU_MASK_ALL/CPU_MASK_NONE: remove from deprecated region.
staging/lustre/o2iblnd: Don't use cpus_weight
staging/lustre/libcfs: replace deprecated cpus_ calls with cpumask_
staging/lustre/ptlrpc: Do not use deprecated cpus_* functions
blackfin: fix up obsolete cpu function usage.
parisc: fix up obsolete cpu function usage.
tile: fix up obsolete cpu function usage.
arm64: fix up obsolete cpu function usage.
mips: fix up obsolete cpu function usage.
x86: fix up obsolete cpu function usage.
...
Pull PMEM driver from Ingo Molnar:
"This is the initial support for the pmem block device driver:
persistent non-volatile memory space mapped into the system's physical
memory space as large physical memory regions.
The driver is based on Intel code, written by Ross Zwisler, with fixes
by Boaz Harrosh, integrated with x86 e820 memory resource management
and tidied up by Christoph Hellwig.
Note that there were two other separate pmem driver submissions to
lkml: but apparently all parties (Ross Zwisler, Boaz Harrosh) are
reasonably happy with this initial version.
This version enables minimal support that enables persistent memory
devices out in the wild to work as block devices, identified through a
magic (non-standard) e820 flag and auto-discovered if
CONFIG_X86_PMEM_LEGACY=y, or added explicitly through manipulating the
memory maps via the "memmap=..." boot option with the new, special '!'
modifier character.
Limitations: this is a regular block device, and since the pmem areas
are not struct page backed, they are invisible to the rest of the
system (other than the block IO device), so direct IO to/from pmem
areas, direct mmap() or XIP is not possible yet. The page cache will
also shadow and double buffer pmem contents, etc.
Initial support is for x86"
* 'x86-pmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
drivers/block/pmem: Fix 32-bit build warning in pmem_alloc()
drivers/block/pmem: Add a driver for persistent memory
x86/mm: Add support for the non-standard protected e820 type
Pull x86 fixes from Ingo Molnar:
"This tree includes:
- an FPU related crash fix
- a ptrace fix (with matching testcase in tools/testing/selftests/)
- an x86 Kconfig DMA-config defaults tweak to better avoid
non-working drivers"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected
x86/fpu: Load xsave pointer *after* initialization
x86/ptrace: Fix the TIF_FORCED_TF logic in handle_signal()
x86, selftests: Add single_step_syscall test
Pull perf updates from Ingo Molnar:
"This update has mostly fixes, but also other bits:
- perf tooling fixes
- PMU driver fixes
- Intel Broadwell PMU driver HW-enablement for LBR callstacks
- a late coming 'perf kmem' tool update that enables it to also
analyze page allocation data. Note, this comes with MM tracepoint
changes that we believe to not break anything: because it changes
the formerly opaque 'struct page *' field that uniquely identifies
pages to 'pfn' which identifies pages uniquely too, but isn't as
opaque and can be used for other purposes as well"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/pt: Fix and clean up error handling in pt_event_add()
perf/x86/intel: Add Broadwell support for the LBR callstack
perf/x86/intel/rapl: Fix energy counter measurements but supporing per domain energy units
perf/x86/intel: Fix Core2,Atom,NHM,WSM cycles:pp events
perf/x86: Fix hw_perf_event::flags collision
perf probe: Fix segfault when probe with lazy_line to file
perf probe: Find compilation directory path for lazy matching
perf probe: Set retprobe flag when probe in address-based alternative mode
perf kmem: Analyze page allocator events also
tracing, mm: Record pfn instead of pointer to struct page
Dan Carpenter reported that pt_event_add() has buggy
error handling logic: it returns 0 instead of -EBUSY when
it fails to start a newly added event.
Furthermore, the control flow in this function is messy,
with cleanup labels mixed with direct returns.
Fix the bug and clean up the code by converting it to
a straight fast path for the regular non-failing case,
plus a clear sequence of cascading goto labels to do
all cleanup.
NOTE: I materially changed the existing clean up logic in the
pt_event_start() failure case to use the direct
perf_aux_output_end() path, not pt_event_del(), because
perf_aux_output_end() is enough here.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150416103830.GB7847@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
So I was playing with gdb today and did this simple thing:
gdb /bin/ls
...
(gdb) run
Box exploded with this splat:
BUG: unable to handle kernel NULL pointer dereference at 00000000000001d0
IP: [<ffffffff8100fe5a>] xstateregs_get+0x7a/0x120
[...]
Call Trace:
ptrace_regset
ptrace_request
? wait_task_inactive
? preempt_count_sub
arch_ptrace
? ptrace_get_task_struct
SyS_ptrace
system_call_fastpath
... because we do cache &target->thread.fpu.state->xsave into the
local variable xsave but that pointer is NULL at that time and
it gets initialized later, in init_fpu(), see:
e7f180dcd8 ("x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave")
The fix is simple: load xsave *after* init_fpu() has run.
Also do the same in xstateregs_set(), as suggested by Oleg Nesterov.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tavis Ormandy <taviso@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1429209697-5902-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Same as Haswell, Broadwell also support the LBR callstack.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1427962377-40955-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
RAPL energy hardware unit can vary within a single CPU package, e.g.
HSW server DRAM has a fixed energy unit of 15.3 uJ (2^-16) whereas
the unit on other domains can be enumerated from power unit MSR.
There might be other variations in the future, this patch adds
per cpu model quirk to allow special handling of certain cpus.
hw_unit is also removed from per cpu data since it is not per cpu
and the sampling rate for energy counter is typically not high.
Without this patch, DRAM domain on HSW servers will be counted
4x higher than the real energy counter.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1427405325-780-1-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Ingo reported that cycles:pp didn't work for him on some machines.
It turns out that in this commit:
af4bdcf675 perf/x86/intel: Disallow flags for most Core2/Atom/Nehalem/Westmere events
Andi forgot to explicitly allow that event when he
disabled event flags for PEBS on those uarchs.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: af4bdcf675 ("perf/x86/intel: Disallow flags for most Core2/Atom/Nehalem/Westmere events")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Somehow we ended up with overlapping flags when merging the
RDPMC control flag - this is bad, fix it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When the TIF_SINGLESTEP tracee dequeues a signal,
handle_signal() clears TIF_FORCED_TF and X86_EFLAGS_TF but
leaves TIF_SINGLESTEP set.
If the tracer does PTRACE_SINGLESTEP again, enable_single_step()
sets X86_EFLAGS_TF but not TIF_FORCED_TF. This means that the
subsequent PTRACE_CONT doesn't not clear X86_EFLAGS_TF, and the
tracee gets the wrong SIGTRAP.
Test-case (needs -O2 to avoid prologue insns in signal handler):
#include <unistd.h>
#include <stdio.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/user.h>
#include <assert.h>
#include <stddef.h>
void handler(int n)
{
asm("nop");
}
int child(void)
{
assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0);
signal(SIGALRM, handler);
kill(getpid(), SIGALRM);
return 0x23;
}
void *getip(int pid)
{
return (void*)ptrace(PTRACE_PEEKUSER, pid,
offsetof(struct user, regs.rip), 0);
}
int main(void)
{
int pid, status;
pid = fork();
if (!pid)
return child();
assert(wait(&status) == pid);
assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGALRM);
assert(ptrace(PTRACE_SINGLESTEP, pid, 0, SIGALRM) == 0);
assert(wait(&status) == pid);
assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGTRAP);
assert((getip(pid) - (void*)handler) == 0);
assert(ptrace(PTRACE_SINGLESTEP, pid, 0, SIGALRM) == 0);
assert(wait(&status) == pid);
assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGTRAP);
assert((getip(pid) - (void*)handler) == 1);
assert(ptrace(PTRACE_CONT, pid, 0,0) == 0);
assert(wait(&status) == pid);
assert(WIFEXITED(status) && WEXITSTATUS(status) == 0x23);
return 0;
}
The last assert() fails because PTRACE_CONT wrongly triggers
another single-step and X86_EFLAGS_TF can't be cleared by
debugger until the tracee does sys_rt_sigreturn().
Change handle_signal() to do user_disable_single_step() if
stepping, we do not need to preserve TIF_SINGLESTEP because we
are going to do ptrace_notify(), and it is simply wrong to leak
this bit.
While at it, change the comment to explain why we also need to
clear TF unconditionally after setup_rt_frame().
Note: in the longer term we should probably change
setup_sigcontext() to use get_flags() and then just remove this
user_disable_single_step(). And, the state of TIF_FORCED_TF can
be wrong after restore_sigcontext() which can set/clear TF, this
needs another fix.
This fix fixes the 'single_step_syscall_32' testcase in
the x86 testsuite:
Before:
~/linux/tools/testing/selftests/x86> ./single_step_syscall_32
[RUN] Set TF and check nop
[OK] Survived with TF set and 9 traps
[RUN] Set TF and check int80
[OK] Survived with TF set and 9 traps
[RUN] Set TF and check a fast syscall
[WARN] Hit 10000 SIGTRAPs with si_addr 0xf7789cc0, ip 0xf7789cc0
Trace/breakpoint trap (core dumped)
After:
~/linux/linux/tools/testing/selftests/x86> ./single_step_syscall_32
[RUN] Set TF and check nop
[OK] Survived with TF set and 9 traps
[RUN] Set TF and check int80
[OK] Survived with TF set and 9 traps
[RUN] Set TF and check a fast syscall
[OK] Survived with TF set and 39 traps
[RUN] Fast syscall with TF cleared
[OK] Nothing unexpected happened
Reported-by: Evan Teran <eteran@alum.rit.edu>
Reported-by: Pedro Alves <palves@redhat.com>
Tested-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.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: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
[ Added x86 self-test info. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge second patchbomb from Andrew Morton:
- the rest of MM
- various misc bits
- add ability to run /sbin/reboot at reboot time
- printk/vsprintf changes
- fiddle with seq_printf() return value
* akpm: (114 commits)
parisc: remove use of seq_printf return value
lru_cache: remove use of seq_printf return value
tracing: remove use of seq_printf return value
cgroup: remove use of seq_printf return value
proc: remove use of seq_printf return value
s390: remove use of seq_printf return value
cris fasttimer: remove use of seq_printf return value
cris: remove use of seq_printf return value
openrisc: remove use of seq_printf return value
ARM: plat-pxa: remove use of seq_printf return value
nios2: cpuinfo: remove use of seq_printf return value
microblaze: mb: remove use of seq_printf return value
ipc: remove use of seq_printf return value
rtc: remove use of seq_printf return value
power: wakeup: remove use of seq_printf return value
x86: mtrr: if: remove use of seq_printf return value
linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK
MAINTAINERS: CREDITS: remove Stefano Brivio from B43
.mailmap: add Ricardo Ribalda
CREDITS: add Ricardo Ribalda Delgado
...
