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CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32
which doesn't exists.
Fixing it leads to a deadlock due to a vital register getting
clobbered in _switch().
Change dependency to PPC32 and use r0 instead of r4 in _switch()
Fixes: e2fb9f5444 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/540242f7d4573f7cdf1b3bf46bb35f743b2cd68f.1587124651.git.christophe.leroy@c-s.fr
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls don't
use the exception entry path anymore. It is therefore pointless
to restore r0 and r6-r8 after calling trace_hardirqs_off().
In the meantime, drop the '2:' label which is unused and misleading.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d2c6dc65d27e83964eb05f16a126161ab6455eea.1578388585.git.christophe.leroy@c-s.fr
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls from
kernel are unexpected and can have catastrophic consequences
as it will destroy the kernel stack.
Test MSR_PR on syscall entry. In case syscall is from kernel,
emit a warning and return ENOSYS error.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
When CONFIG_PROVE_LOCKING is selected together with (now default)
CONFIG_VMAP_STACK, kernel enter deadlock during boot.
At the point of checking whether interrupts are enabled or not, the
value of MSR saved on stack is read using the physical address of the
stack. But at this point, when using VMAP stack the DATA MMU
translation has already been re-enabled, leading to deadlock.
Don't use the physical address of the stack when
CONFIG_VMAP_STACK is set.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 028474876f ("powerpc/32: prepare for CONFIG_VMAP_STACK")
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/daeacdc0dec0416d1c587cc9f9e7191ad3068dc0.1581095957.git.christophe.leroy@c-s.fr
- Implement user_access_begin() and friends for our platforms that support
controlling kernel access to userspace.
- Enable CONFIG_VMAP_STACK on 32-bit Book3S and 8xx.
- Some tweaks to our pseries IOMMU code to allow SVMs ("secure" virtual
machines) to use the IOMMU.
- Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 32-bit VDSO, and
some other improvements.
- A series to use the PCI hotplug framework to control opencapi card's so that
they can be reset and re-read after flashing a new FPGA image.
As well as other minor fixes and improvements as usual.
Thanks to:
Alastair D'Silva, Alexandre Ghiti, Alexey Kardashevskiy, Andrew Donnellan,
Aneesh Kumar K.V, Anju T Sudhakar, Bai Yingjie, Chen Zhou, Christophe Leroy,
Frederic Barrat, Greg Kurz, Jason A. Donenfeld, Joel Stanley, Jordan Niethe,
Julia Lawall, Krzysztof Kozlowski, Laurent Dufour, Laurentiu Tudor, Linus
Walleij, Michael Bringmann, Nathan Chancellor, Nicholas Piggin, Nick
Desaulniers, Oliver O'Halloran, Peter Ujfalusi, Pingfan Liu, Ram Pai, Randy
Dunlap, Russell Currey, Sam Bobroff, Sebastian Andrzej Siewior, Shawn
Anastasio, Stephen Rothwell, Steve Best, Sukadev Bhattiprolu, Thiago Jung
Bauermann, Tyrel Datwyler, Vaibhav Jain.
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Merge tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"A pretty small batch for us, and apologies for it being a bit late, I
wanted to sneak Christophe's user_access_begin() series in.
Summary:
- Implement user_access_begin() and friends for our platforms that
support controlling kernel access to userspace.
- Enable CONFIG_VMAP_STACK on 32-bit Book3S and 8xx.
- Some tweaks to our pseries IOMMU code to allow SVMs ("secure"
virtual machines) to use the IOMMU.
- Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 32-bit
VDSO, and some other improvements.
- A series to use the PCI hotplug framework to control opencapi
card's so that they can be reset and re-read after flashing a new
FPGA image.
As well as other minor fixes and improvements as usual.
Thanks to: Alastair D'Silva, Alexandre Ghiti, Alexey Kardashevskiy,
Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Bai Yingjie, Chen
Zhou, Christophe Leroy, Frederic Barrat, Greg Kurz, Jason A.
Donenfeld, Joel Stanley, Jordan Niethe, Julia Lawall, Krzysztof
Kozlowski, Laurent Dufour, Laurentiu Tudor, Linus Walleij, Michael
Bringmann, Nathan Chancellor, Nicholas Piggin, Nick Desaulniers,
Oliver O'Halloran, Peter Ujfalusi, Pingfan Liu, Ram Pai, Randy Dunlap,
Russell Currey, Sam Bobroff, Sebastian Andrzej Siewior, Shawn
Anastasio, Stephen Rothwell, Steve Best, Sukadev Bhattiprolu, Thiago
Jung Bauermann, Tyrel Datwyler, Vaibhav Jain"
* tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (131 commits)
powerpc: configs: Cleanup old Kconfig options
powerpc/configs/skiroot: Enable some more hardening options
powerpc/configs/skiroot: Disable xmon default & enable reboot on panic
powerpc/configs/skiroot: Enable security features
powerpc/configs/skiroot: Update for symbol movement only
powerpc/configs/skiroot: Drop default n CONFIG_CRYPTO_ECHAINIV
powerpc/configs/skiroot: Drop HID_LOGITECH
powerpc/configs: Drop NET_VENDOR_HP which moved to staging
powerpc/configs: NET_CADENCE became NET_VENDOR_CADENCE
powerpc/configs: Drop CONFIG_QLGE which moved to staging
powerpc: Do not consider weak unresolved symbol relocations as bad
powerpc/32s: Fix kasan_early_hash_table() for CONFIG_VMAP_STACK
powerpc: indent to improve Kconfig readability
powerpc: Provide initial documentation for PAPR hcalls
powerpc: Implement user_access_save() and user_access_restore()
powerpc: Implement user_access_begin and friends
powerpc/32s: Prepare prevent_user_access() for user_access_end()
powerpc/32s: Drop NULL addr verification
powerpc/kuap: Fix set direction in allow/prevent_user_access()
powerpc/32s: Fix bad_kuap_fault()
...
Commit f7354ccac8 ("powerpc/32: Remove CURRENT_THREAD_INFO and
rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when
_TLF_SLEEPING is set) by delaying the tovirt(r2, r2).
This is because r2 is not restored by fast_exception_return. It used
to work (by chance ?) because CPU wake-up interrupt never comes from
user, so r2 is expected to point to 'current' on return.
Commit e2fb9f5444 ("powerpc/32: Prepare for Kernel Userspace Access
Protection") broke it even more by clobbering r0 which is not
restored by fast_exception_return either.
Use r6 instead of r0. This is possible because r3-r6 are restored by
fast_exception_return and only r3-r5 are used for exception arguments.
For r2 it could be converted back to virtual address, but stay on the
safe side and restore it from the stack instead. It should be live
in the cache at that moment, so loading from the stack should make
no difference compared to converting it from phys to virt.
Fixes: f7354ccac8 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU")
Fixes: e2fb9f5444 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr
A few changes to retrieve DAR and DSISR from struct regs
instead of retrieving them directly, as they may have
changed due to a TLB miss.
Also modifies hash_page() and friends to work with virtual
data addresses instead of physical ones. Same on load_up_fpu()
and load_up_altivec().
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Fix tovirt_vmstack call in head_32.S to fix CHRP build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2e2509a242fd5f3e23df4a06530c18060c4d321e.1576916812.git.christophe.leroy@c-s.fr
To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU
Translation for accessing the stack. Before doing that it must save
SRR0, SRR1 and also DAR and DSISR when relevant, in order to not
loose them in case there is a Data TLB Miss once the translation is
reactivated.
This patch adds fields in thread struct for saving those registers.
It prepares entry_32.S to handle exception entry with
Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to
save SRR0, SRR1, DAR and DSISR then reenables Data MMU.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.
Switch the entry code over to use CONFIG_PREEMPTION.
[bigeasy: +Kconfig]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20191024160458.vlnf3wlcyjl2ich7@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Wire up the new clone3 syscall added in commit 7f192e3cd3 ("fork:
add clone3").
This requires a ppc_clone3 wrapper, in order to save the non-volatile
GPRs before calling into the generic syscall code. Otherwise we hit
the BUG_ON in CHECK_FULL_REGS in copy_thread().
Lightly tested using Christian's test code on a Power8 LE VM.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Christian Brauner <christian@brauner.io>
Link: https://lore.kernel.org/r/20190724140259.23554-1-mpe@ellerman.id.au
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
[mpe: Rebase since CURRENT_THREAD_INFO() removal]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
No need to add dummy frames when calling trace_hardirqs_on or
trace_hardirqs_off. GCC properly handles empty stacks.
In addition, powerpc doesn't set CONFIG_FRAME_POINTER, therefore
__builtin_return_address(1..) returns NULL at all time. So the
dummy frames are definitely unneeded here.
In the meantime, avoid reading memory for loading r1 with a value
we already know.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As syscalls are now handled via a fast entry path, syscall related
actions can be removed from the generic transfer_to_handler path.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch implements a fast entry for syscalls.
Syscalls don't have to preserve non volatile registers except LR.
This patch then implement a fast entry for syscalls, where
volatile registers get clobbered.
As this entry is dedicated to syscall it always sets MSR_EE
and warns in case MSR_EE was previously off
It also assumes that the call is always from user, system calls are
unexpected from kernel.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch implements a fast entry for syscalls.
Syscalls don't have to preserve non volatile registers except LR.
This patch then implement a fast entry for syscalls, where
volatile registers get clobbered.
As this entry is dedicated to syscall it always sets MSR_EE
and warns in case MSR_EE was previously off
It also assumes that the call is always from user, system calls are
unexpected from kernel.
The overall series improves null_syscall selftest by 12,5% on an 83xx
and by 17% on a 8xx.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[text mostly copied from benh's RFC/WIP]
ppc32 are still doing something rather gothic and wrong on 32-bit
which we stopped doing on 64-bit a while ago.
We have that thing where some handlers "copy" the EE value from the
original stack frame into the new MSR before transferring to the
handler.
Thus for a number of exceptions, we enter the handlers with interrupts
enabled.
This is rather fishy, some of the stuff that handlers might do early
on such as irq_enter/exit or user_exit, context tracking, etc...
should be run with interrupts off afaik.
Generally our handlers know when to re-enable interrupts if needed.
The problem we were having is that we assumed these interrupts would
return with interrupts enabled. However that isn't the case.
Instead, this patch changes things so that we always enter exception
handlers with interrupts *off* with the notable exception of syscalls
which are special (and get a fast path).
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As preparation for using head_32.h for head_40x.S, move
LOAD_MSR_KERNEL() there and use it to load r10 with MSR_KERNEL value.
In the mean time, this patch modifies it so that it takes into account
the size of the passed value to determine if 'li' can be used or if
'lis/ori' is needed instead of using the size of MSR_KERNEL. This is
done by using gas macro.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
To implement Kernel Userspace Execution Prevention, this patch
sets NX bit on all user segments on kernel entry and clears NX bit
on all user segments on kernel exit.
Note that powerpc 601 doesn't have the NX bit, so KUEP will not
work on it. A warning is displayed at startup.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds ASM macros for saving, restoring and checking
the KUAP state, and modifies setup_32 to call them on exceptions
from kernel.
The macros are defined as empty by default for when CONFIG_PPC_KUAP
is not selected and/or for platforms which don't handle (yet) KUAP.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
syscalls are from user only, so we can account time without checking
whether returning to kernel or user as it will only be user.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that thread_info is similar to task_struct, its address is in r2
so CURRENT_THREAD_INFO() macro is useless. This patch removes it.
This patch also moves the 'tovirt(r2, r2)' down just before the
reactivation of MMU translation, so that we keep the physical address
of 'current' in r2 until then. It avoids a few calls to tophys().
At the same time, as the 'cpu' field is not anymore in thread_info,
TI_CPU is renamed TASK_CPU by this patch.
It also allows to get rid of a couple of
'#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE' as ACCOUNT_CPU_USER_ENTRY()
and ACCOUNT_CPU_USER_EXIT() are empty when
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not defined.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Fix a missed conversion of TI_CPU idle_6xx.S]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
thread_info is not anymore in the stack, so the entire stack
can now be used.
There is also no risk anymore of corrupting task_cpu(p) with a
stack overflow so the patch removes the test.
When doing this, an explicit test for NULL stack pointer is
needed in validate_sp() as it is not anymore implicitely covered
by the sizeof(thread_info) gap.
In the meantime, with the previous patch all pointers to the stacks
are not anymore pointers to thread_info so this patch changes them
to void*
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch activates CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.
Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are leaked,
making a number of attacks more difficult.
This has the following consequences:
- thread_info is now located at the beginning of task_struct.
- The 'cpu' field is now in task_struct, and only exists when
CONFIG_SMP is active.
- thread_info doesn't have anymore the 'task' field.
This patch:
- Removes all recopy of thread_info struct when the stack changes.
- Changes the CURRENT_THREAD_INFO() macro to point to current.
- Selects CONFIG_THREAD_INFO_IN_TASK.
- Modifies raw_smp_processor_id() to get ->cpu from current without
including linux/sched.h to avoid circular inclusion and without
including asm/asm-offsets.h to avoid symbol names duplication
between ASM constants and C constants.
- Modifies klp_init_thread_info() to take a task_struct pointer
argument.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add task_stack.h to livepatch.h to fix build fails]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch renames THREAD_INFO to TASK_STACK, because it is in fact
the offset of the pointer to the stack in task_struct so this pointer
will not be impacted by the move of THREAD_INFO.
Also make it available on 64-bit, as we'll need it there when we
activate THREAD_INFO_IN_TASK.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make available on 64-bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
40x/booke have another path to reach 3f from transfer_to_handler,
make sure it also calls ACCOUNT_CPU_USER_ENTRY() when
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is selected.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When calling RTAS, the stack pointer is stored in SPRN_SPRG2
in order to be able to restore it in case of machine check in RTAS.
As machine check is not a perfomance critical path, this patch
frees SPRN_SPRG2 by using a field in thread struct instead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
MSR[RI] has already been cleared a few lines above.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Today we have:
config PPC_BOOK3S_32
bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx"
[depends on PPC32 within a choice]
config PPC_BOOK3S
def_bool y
depends on PPC_BOOK3S_32 || PPC_BOOK3S_64
config 6xx
def_bool y
depends on PPC32 && PPC_BOOK3S
6xx is therefore redundant with PPC_BOOK3S_32.
In order to make the code clearer, lets use preferably PPC_BOOK3S_32.
This will allow to remove CONFIG_6xx in a later patch.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PPC32 uses nonrecoverable_exception() while PPC64 uses
unrecoverable_exception().
Both functions are doing almost the same thing.
This patch removes nonrecoverable_exception()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Used barrier_nospec to sanitize the syscall table.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
files not using feature fixup don't need asm/feature-fixups.h
files using feature fixup need asm/feature-fixups.h
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Syscalls are not allowed inside restartable sequences, so add a call to
rseq_syscall() at the very beginning of system call exiting path for
CONFIG_DEBUG_RSEQ=y kernel. This could help us to detect whether there
is a syscall issued inside restartable sequences.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Hunter <ahh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20180602124408.8430-10-mathieu.desnoyers@efficios.com
In TLB miss handlers, updating the perf counter is only useful
when performing a perf analysis. As it has a noticeable overhead,
let's only do it when needed.
In order to do so, the exit of the miss handlers will be patched
when starting/stopping 'perf': the first register restore
instruction of each exit point will be replaced by a jump to
the counting code.
Once this is done, CONFIG_PPC_8xx_PERF_EVENT becomes useless as
this feature doesn't add any overhead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
By default, the 8xx pins an ITLB on the first 8M of memory in order
to avoid any ITLB miss on kernel code.
However, with some debug functions like DEBUG_PAGEALLOC and
DEBUG_RODATA, pinning TLBs is contradictory.
In order to avoid any ITLB miss in a critical section without pinning
TLBs, we have to ensure that there is no page boundary crossed between
the setup of a new value in SRR0/SRR1 and the associated RFI.
The functions modifying srr0/srr1 are all located in setup_32.S.
They are spread over almost 4kbytes.
The patch forces a 12 bits (4kbytes) alignment for those
functions. This garanties that the functions remain in a
single 4k page.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit d300627c6a ("powerpc/6xx: Handle DABR match before calling
do_page_fault") breaks non 6xx platforms.
Failed to execute /init (error -14)
Starting init: /bin/sh exists but couldn't execute it (error -14)
Kernel panic - not syncing: No working init found. Try passing init= ...
CPU: 0 PID: 1 Comm: init Not tainted 4.13.0-rc3-s3k-dev-00143-g7aa62e972a56 #56
Call Trace:
panic+0x108/0x250 (unreliable)
rootfs_mount+0x0/0x58
ret_from_kernel_thread+0x5c/0x64
Rebooting in 180 seconds..
This is because in handle_page_fault(), the call to do_page_fault() has been
mistakenly enclosed inside an #ifdef CONFIG_6xx
Fixes: d300627c6a ("powerpc/6xx: Handle DABR match before calling do_page_fault")
Brown-paper-bag-to-be-worn-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On legacy 6xx 32-bit procesors, we checked for the DABR match bit
in DSISR from do_page_fault(), in the middle of a pile of ifdef's
because all other CPU types do it in assembly prior to calling
do_page_fault. Fix that.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Add #ifdef CONFIG_6xx]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
entry_*.S now includes a lot more than just kernel entry/exit code. As a
first step at cleaning this up, let's split out the ftrace bits into
separate files. Also move all related tracing code into a new trace/
subdirectory.
No functional changes.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Highlights include:
- An update of the disassembly code used by xmon to the latest versions in
binutils. We've received permission from all the authors of the relevant
binutils changes to relicense their changes to the relevant files from GPLv3
to GPLv2, for inclusion in Linux. Thanks to Peter Bergner for doing the leg
work to get permission from everyone.
- Addition of the "architected" Power9 CPU table entry, allowing us to boot
in Power9 architected mode under a hypervisor.
- Updates to the Power9 PMU code.
- Implementation of clear_bit_unlock_is_negative_byte() to optimise
unlock_page().
- Freescale updates from Scott: "Highlights include 8xx breakpoints and perf,
t1042rdb display support, and board updates."
Thanks to:
Al Viro, Andrew Donnellan, Aneesh Kumar K.V, Balbir Singh, Douglas Miller,
Frédéric Weisbecker, Gavin Shan, Madhavan Srinivasan, Michael Roth, Nathan
Fontenot, Naveen N. Rao, Nicholas Piggin, Peter Bergner, Paul E. McKenney,
Rashmica Gupta, Russell Currey, Sahil Mehta, Stewart Smith.
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Merge tag 'powerpc-4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull more powerpc updates from Michael Ellerman:
"Highlights include:
- an update of the disassembly code used by xmon to the latest
versions in binutils. We've received permission from all the
authors of the relevant binutils changes to relicense their changes
to the relevant files from GPLv3 to GPLv2, for inclusion in Linux.
Thanks to Peter Bergner for doing the leg work to get permission
from everyone.
- addition of the "architected" Power9 CPU table entry, allowing us
to boot in Power9 architected mode under a hypervisor.
- updates to the Power9 PMU code.
- implementation of clear_bit_unlock_is_negative_byte() to optimise
unlock_page().
- Freescale updates from Scott: "Highlights include 8xx breakpoints
and perf, t1042rdb display support, and board updates."
Thanks to:
Al Viro, Andrew Donnellan, Aneesh Kumar K.V, Balbir Singh, Douglas
Miller, Frédéric Weisbecker, Gavin Shan, Madhavan Srinivasan,
Michael Roth, Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Peter
Bergner, Paul E. McKenney, Rashmica Gupta, Russell Currey, Sahil
Mehta, Stewart Smith"
* tag 'powerpc-4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (48 commits)
powerpc: Remove leftover cputime_to_nsecs call causing build error
powerpc/mm/hash: Always clear UPRT and Host Radix bits when setting up CPU
powerpc/optprobes: Fix TOC handling in optprobes trampoline
powerpc/pseries: Advertise Hot Plug Event support to firmware
cxl: fix nested locking hang during EEH hotplug
powerpc/xmon: Dump memory in CPU endian format
powerpc/pseries: Revert 'Auto-online hotplugged memory'
powerpc/powernv: Make PCI non-optional
powerpc/64: Implement clear_bit_unlock_is_negative_byte()
powerpc/powernv: Remove unused variable in pnv_pci_sriov_disable()
powerpc/kernel: Remove error message in pcibios_setup_phb_resources()
powerpc/mm: Fix typo in set_pte_at()
pci/hotplug/pnv-php: Disable MSI and PCI device properly
pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts
pci/hotplug/pnv-php: Remove WARN_ON() in pnv_php_put_slot()
powerpc: Add POWER9 architected mode to cputable
powerpc/perf: use is_kernel_addr macro in perf_get_misc_flags()
powerpc/perf: Avoid FAB_*_MATCH checks for power9
powerpc/perf: Add restrictions to PMC5 in power9 DD1
powerpc/perf: Use Instruction Counter value
...
This patch has been reworked since RFC version. In the RFC, this patch
was preceded by a patch clearing MSR RI for all PPC32 at all time at
exception prologs. Now MSR RI clearing is done only when this 8xx perf
events functionality is compiled in, it is therefore limited to 8xx
and merged inside this patch.
Other main changes have been to take into account detailed review from
Peter Zijlstra. The instructions counter has been reworked to behave
as a free running counter like the three other counters.
The 8xx has no PMU, however some events can be emulated by other means.
This patch implements the following events (as reported by 'perf list'):
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
dTLB-load-misses [Hardware cache event]
iTLB-load-misses [Hardware cache event]
'cycles' event is implemented using the timebase clock. Timebase clock
corresponds to CPU clock divided by 16, so number of cycles is
approximatly 16 times the number of TB ticks
On the 8xx, TLB misses are handled by software. It is therefore
easy to count all TLB misses each time the TLB miss exception is
called.
'instructions' is calculated by using instruction watchpoint counter.
This patch sets counter A to count instructions at address greater
than 0, hence we count all instructions executed while MSR RI bit is
set. The counter is set to the maximum which is 0xffff. Every 65535
instructions, debug instruction breakpoint exception fires. The
exception handler increments a counter in memory which then
represent the upper part of the instruction counter. We therefore
end up with a 48 bits counter. In order to avoid unnecessary overhead
while no perf event is active, this counter is started when the first
event referring to this counter is added, and the counter is stopped
when the last event referring to it is deleted. In order to properly
support breakpoint exceptions, MSR RI bit has to be unset in exception
epilogs in order to avoid breakpoint exceptions during critical
sections during changes to SRR0 and SRR1 would be problematic.
All counters are handled as free running counters.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
FIX_SRR1() is defined as blank. Last useful instance of FIX_SRR1()
was removed by commit 40ef8cbc6d ("powerpc: Get 64-bit configs to
compile with ARCH=powerpc") in 2005.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
Unfortunately the stack protector support we merged recently only works
on some toolchains. If the toolchain is built without glibc support
everything works fine, but if glibc is built then it leads to a panic
at boot.
The solution is not rc5 material, so revert the support for now. This
reverts commits:
6533b7c16e ("powerpc: Initial stack protector (-fstack-protector) support")
902e06eb86 ("powerpc/32: Change the stack protector canary value per task")
Fixes: 6533b7c16e ("powerpc: Initial stack protector (-fstack-protector) support")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Partially copied from commit df0698be14 ("ARM: stack protector:
change the canary value per task")
A new random value for the canary is stored in the task struct whenever
a new task is forked. This is meant to allow for different canary values
per task. On powerpc, GCC expects the canary value to be found in a global
variable called __stack_chk_guard. So this variable has to be updated
with the value stored in the task struct whenever a task switch occurs.
Because the variable GCC expects is global, this cannot work on SMP
unfortunately. So, on SMP, the same initial canary value is kept
throughout, making this feature a bit less effective although it is still
useful.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull kbuild updates from Michal Marek:
- EXPORT_SYMBOL for asm source by Al Viro.
This does bring a regression, because genksyms no longer generates
checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
working on a patch to fix this.
Plus, we are talking about functions like strcpy(), which rarely
change prototypes.
- Fixes for PPC fallout of the above by Stephen Rothwell and Nick
Piggin
- fixdep speedup by Alexey Dobriyan.
- preparatory work by Nick Piggin to allow architectures to build with
-ffunction-sections, -fdata-sections and --gc-sections
- CONFIG_THIN_ARCHIVES support by Stephen Rothwell
- fix for filenames with colons in the initramfs source by me.
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
initramfs: Escape colons in depfile
ppc: there is no clear_pages to export
powerpc/64: whitelist unresolved modversions CRCs
kbuild: -ffunction-sections fix for archs with conflicting sections
kbuild: add arch specific post-link Makefile
kbuild: allow archs to select link dead code/data elimination
kbuild: allow architectures to use thin archives instead of ld -r
kbuild: Regenerate genksyms lexer
kbuild: genksyms fix for typeof handling
fixdep: faster CONFIG_ search
ia64: move exports to definitions
sparc32: debride memcpy.S a bit
[sparc] unify 32bit and 64bit string.h
sparc: move exports to definitions
ppc: move exports to definitions
arm: move exports to definitions
s390: move exports to definitions
m68k: move exports to definitions
alpha: move exports to actual definitions
x86: move exports to actual definitions
...
CLR_TOP32() is defined as blank. Last useful instance of CLR_TOP32()
was removed by commit 40ef8cbc6d ("powerpc: Get 64-bit configs to
compile with ARCH=powerpc") in 2005.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture.
PPC32 doesn't have the PACA structure, so we use the task_info
structure to store the accounting data.
In order to reuse on PPC32 the PPC64 functions, all u64 data has
been replaced by 'unsigned long' so that it is u32 on PPC32 and
u64 on PPC64
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
The API for calling do_syscall_trace_enter() is currently sensible
enough, it just returns the (modified) syscall number.
However once we enable seccomp filter it will get more complicated. When
seccomp filter runs, the seccomp kernel code (via SECCOMP_RET_ERRNO), or
a ptracer (via SECCOMP_RET_TRACE), may reject the syscall and *may* or may
*not* set a return value in r3.
That means the assembler that calls do_syscall_trace_enter() can not
blindly return ENOSYS, it needs to only return ENOSYS if a return value
has not already been set.
There is no way to implement that logic with the current API. So change
the do_syscall_trace_enter() API to make it deal with the return code
juggling, and the assembler can then just return whatever return code it
is given.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Currently on powerpc we have our own #define for the highest (negative)
errno value, called _LAST_ERRNO. This is defined to be 516, for reasons
which are not clear.
The generic code, and x86, use MAX_ERRNO, which is defined to be 4095.
In particular seccomp uses MAX_ERRNO to restrict the value that a
seccomp filter can return.
Currently with the mismatch between _LAST_ERRNO and MAX_ERRNO, a seccomp
tracer wanting to return 600, expecting it to be seen as an error, would
instead find on powerpc that userspace sees a successful syscall with a
return value of 600.
To avoid this inconsistency, switch powerpc to use MAX_ERRNO.
We are somewhat confident that generic syscalls that can return a
non-error value above negative MAX_ERRNO have already been updated to
use force_successful_syscall_return().
I have also checked all the powerpc specific syscalls, and believe that
none of them expect to return a non-error value between -MAX_ERRNO and
-516. So this change should be safe ...
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
We have code to do syscall tracing which is disabled at compile time by
default. It's not been touched since the dawn of time (ie. v2.6.12).
There are now better ways to do syscall tracing, ie. using the
raw_syscall, or syscall tracepoints.
For the specific case of tracing syscalls at boot on a system that
doesn't get to userspace, you can boot with:
trace_event=syscalls tp_printk=on
Which will trace syscalls from boot, and echo all output to the console.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Once upon a time, at least 9 years ago (< 2.6.12), _TIF_SYSCALL_T_OR_A
meant "TRACE or AUDIT". But these days it means TRACE or AUDIT or
SECCOMP or TRACEPOINT or NOHZ.
All of those are implemented via syscall_dotrace() so rename the flag to
that to try and clarify things.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
CONFIG_MCOUNT is not defined anymore, the corresponding #ifdef there
is CONFIG_FUNCTION_TRACER.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Instead of passing in the stack address of the link register
to be modified, just pass in the old value and return the
new value and rely on ftrace_graph_caller to do the
modification.
This removes the exception handling around the stack update -
it isn't needed and we weren't consistent about it. Later on
we would do an unprotected modification:
if (!ftrace_graph_entry(&trace)) {
*parent = old;
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit a9c4e541ea
"powerpc/kprobe: Complete kprobe and migrate exception frame"
introduced a regression:
While returning from exception handling in case of PREEMPT enabled,
_TIF_NEED_RESCHED bit is checked in TI_FLAGS (thread_info flag) of current
task. Only if this bit is set, it should continue with the process of
calling preempt_schedule_irq() to schedule highest priority task if
available.
Current code assumes that r8 contains TI_FLAGS and check this for
_TIF_NEED_RESCHED, but as r8 is modified in the code which executes before
this check, r8 no longer contains the expected TI_FLAGS information.
As a result check for comparison with _TIF_NEED_RESCHED was failing even if
NEED_RESCHED bit is set in the current thread_info flag. Due to this,
preempt_schedule_irq() and in turn scheduler was not getting called even if
highest priority task is ready for execution.
So, store temporary results in r0 instead of r8 to prevent r8 from getting
modified as subsequent code is dependent on its value.
Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
CC: <stable@vger.kernel.org> [v3.7+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Saw this warning again, and this time from the ret_from_fork path.
It seems we could clear the back chain earlier in copy_thread(), which
could cover both path, and also fix potential lockdep usage in
schedule_tail(), or exception occurred before we clear the back chain.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch fixes MAX_STACK_TRACE_ENTRIES too low warning for ppc32,
which is similar to commit 12660b17.
Reported-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull pile 2 of execve and kernel_thread unification work from Al Viro:
"Stuff in there: kernel_thread/kernel_execve/sys_execve conversions for
several more architectures plus assorted signal fixes and cleanups.
There'll be more (in particular, real fixes for the alpha
do_notify_resume() irq mess)..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (43 commits)
alpha: don't open-code trace_report_syscall_{enter,exit}
Uninclude linux/freezer.h
m32r: trim masks
avr32: trim masks
tile: don't bother with SIGTRAP in setup_frame
microblaze: don't bother with SIGTRAP in setup_rt_frame()
mn10300: don't bother with SIGTRAP in setup_frame()
frv: no need to raise SIGTRAP in setup_frame()
x86: get rid of duplicate code in case of CONFIG_VM86
unicore32: remove pointless test
h8300: trim _TIF_WORK_MASK
parisc: decide whether to go to slow path (tracesys) based on thread flags
parisc: don't bother looping in do_signal()
parisc: fix double restarts
bury the rest of TIF_IRET
sanitize tsk_is_polling()
bury _TIF_RESTORE_SIGMASK
unicore32: unobfuscate _TIF_WORK_MASK
mips: NOTIFY_RESUME is not needed in TIF masks
mips: merge the identical "return from syscall" per-ABI code
...
Conflicts:
arch/arm/include/asm/thread_info.h
the only non-obvious part is that current_pt_regs() is really needed
here - task_pt_regs() is NULL for kernel threads; it's OK for ptrace
uses (the thing task_pt_regs() is intended for), but not for us.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We can't emulate stwu since that may corrupt current exception stack.
So we will have to do real store operation in the exception return code.
Firstly we'll allocate a trampoline exception frame below the kprobed
function stack and copy the current exception frame to the trampoline.
Then we can do this real store operation to implement 'stwu', and reroute
the trampoline frame to r1 to complete this exception migration.
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit 9778b696a0 incorrectly
changes the code setting the stack limit on entry to the
kernel to mark the thread_info at the bottom of the stack
out of bounds anymore. This fixes it.
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When I "fixed" the CONFIG_TRACE_IRQFLAGS case on interrupt entry,
I screwed up a little bit with the test for user space vs. kernel.
The code is fine, there's just some dead code around it. I basically
removed the test and always create the added stack frame whether
coming from user or kernel since in any case we do need to save
a bunch of volatile registers or bad things would happen (we can
take page faults in the kernel for example).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
commit a546498f3b
introduced a regression on 32-bit when irq tracing
is enabled by exposing an old bug in our irq tracing
code for exception entry.
The code would save and restore some GPRs around the
calls to the C lockdep code, however, it tries to be
too smart for its own good and restores some of the
GPRs from the exception frame (as saved there on
exception entry).
However, for page faults, we do replace those GPRs with
arguments to do_page_fault before we call transfer_to_handler
and so restoring from the exception frame is plain wrong in
this case.
This was fine as long as we didn't touch the interrupt state
when taking page fault, but when I started doing it, it would
trigger the lockdep calls and the bug.
This fixes it by cleaning up that code a bit. It did create
a small stack frame for the sake of backtraces, so let's
make it a bit bigger and use it to save and restore the
stuff we care about.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We have a few problems when returning to userspace. This is a
quick set of fixes for 3.3, I'll look into a more comprehensive
rework for 3.4. This fixes:
- We kept interrupts soft-disabled when schedule'ing or calling
do_signal when returning to userspace as a result of a hardware
interrupt.
- Rename do_signal to do_notify_resume like all other archs (and
do_signal_pending back to do_signal, which it was before Roland
changed it).
- Add the missing call to key_replace_session_keyring() to
do_notify_resume().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
32-bit variant of the previous patch for 64-bit:
<<
When an interrupt occurs in userspace, we can call trace_hardirqs_on/off()
With one level stack. But if we have irqsoff tracing enabled,
it checks both CALLER_ADDR0 and CALLER_ADDR1. The second call
goes two stack frames up. If this is from user space, then there may
not exist a second stack....
>>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since STACK_FRAME_OVERHEAD is defined in asm/ptrace.h and that
is ASSEMBER safe, we can just include that instead of going via
asm-offsets.h.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds the base support for the 476 processor. The code was
primarily written by Ben Herrenschmidt and Torez Smith, but I've been
maintaining it for a while.
The goal is to have a single binary that will run on 44x and 47x, but
we still have some details to work out. The biggest is that the L1 cache
line size differs on the two platforms, but it's currently a compile-time
option.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Torez Smith <lnxtorez@linux.vnet.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
The kernel uses SPRG registers for various purposes, typically in
low level assembly code as scratch registers or to hold per-cpu
global infos such as the PACA or the current thread_info pointer.
We want to be able to easily shuffle the usage of those registers
as some implementations have specific constraints realted to some
of them, for example, some have userspace readable aliases, etc..
and the current choice isn't always the best.
This patch should not change any code generation, and replaces the
usage of SPRN_SPRGn everywhere in the kernel with a named replacement
and adds documentation next to the definition of the names as to
what those are used for on each processor family.
The only parts that still use the original numbers are bits of KVM
or suspend/resume code that just blindly needs to save/restore all
the SPRGs.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Based on initial work from: Dale Farnsworth <dale@farnsworth.org>
Add the low level irq tracing hooks for 32-bit powerpc needed
to enable full lockdep functionality.
The approach taken to deal with the code in entry_32.S is that
we don't trace all the transitions of MSR:EE when we just turn
it off to peek at TI_FLAGS without races. Only when we are
calling into C code or returning from exceptions with a state
that have changed from what lockdep thinks.
There's a little bugger though: If we take an exception that
keeps interrupts enabled (such as an alignment exception) while
interrupts are enabled, we will call trace_hardirqs_on() on the
way back spurriously. Not a big deal, but to get rid of it would
require remembering in pt_regs that the exception was one of the
type that kept interrupts enabled which we don't know at this
stage. (Well, we could test all cases for regs->trap but that
sucks too much).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Kumar Gala <galak@kernel.crashing.org>
Create a new header that becomes a single location for defining PowerPC
opcodes used by code that is either generationg instructions
at runtime (fixups, debug, etc.), emulating instructions, or just
compiling instructions old assemblers don't know about.
We currently don't handle the floating point emulation or alignment decode
as both are better handled by the specific decode support they already
have.
Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions
since older assemblers don't know about them.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch gets function graph tracing working with dynamic function
tracer on PowerPC32.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch ports the function graph tracer for PowerPC, but only
for static function tracing.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Impact: clean up
Use a macro to save and restore the registers for PowerPC32,
since that code is duplicated.
This is similar to the work done by Cyrill Gorcunov for the
mcount code in x86_64.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The Power ISA 2.06 spec introduces a standard MMU programming model that
is based on the Freescale Book-E MMU programing model. The Freescale
version is pretty backwards compatiable with the ISA 2.06 definition so
we are starting to refactor some of the Freescale code so it can be
easily shared.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Impact: quicken mcount calls that are not replaced by dyn ftrace
Dynamic ftrace no longer does on the fly recording of mcount locations.
The mcount locations are now found at compile time. The mcount
function no longer needs to store registers and call a stub function.
It can now just simply return.
Since there are some functions that do not get converted to a nop
(.init sections and other code that may disappear), this patch should
help speed up that code.
Also, the stub for mcount on PowerPC 32 can not be a simple branch
link register like it is on PowerPC 64. According to the ABI specification:
"The _mcount routine is required to restore the link register from
the stack so that the profiling code can be inserted transparently,
whether or not the profiled function saves the link register itself."
This means that we must restore the link register that was used
to make the call to mcount. The minimal mcount function for PPC32
ends up being:
mcount:
mflr r0
mtctr r0
lwz r0, 4(r1)
mtlr r0
bctr
Where we move the link register used to call mcount into the
ctr register, and then restore the link register from the stack.
Then we use the ctr register to jump back to the mcount caller.
The r0 register is free for us to use.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Due to confusion between the ftrace infrastructure and the gcc profiling
tracer "ftrace", this patch renames the config options from FTRACE to
FUNCTION_TRACER. The other two names that are offspring from FTRACE
DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same.
This patch was generated mostly by script, and partially by hand.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This adds TIF_NOTIFY_RESUME support for powerpc. When set,
we call tracehook_notify_resume() on the way to user mode.
This overloads do_signal() to do the work, but changes its
arguments to it has the TIF_* bits handy in a register and
drops the useless first argument that was always zero.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This changes powerpc syscall tracing to use the new tracehook.h entry
points. There is no change, only cleanup.
In addition, the assembly changes allow do_syscall_trace_enter() to
abort the syscall without losing the information about the original
r0 value.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* CONFIG_BOOKE is selected by CONFIG_44x so we dont need both
* Fixed a few comments
* Go back to only using DBCR0_IDM to determine if we are using
debug resources.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch implements support for HW based watchpoint via the
DBSR_DAC (Data Address Compare) facility of the BookE processors.
It does so by interfacing with the existing DABR breakpoint code
and adding the necessary bits and pieces for the new bits to
be properly set or cleared
Signed-off-by: Luis Machado <luisgpm@br.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The e500 core enter DOZE/NAP power-saving modes when the core go to
cpu_idle routine.
The power management default running mode is DOZE, If the user
echo 1 > /proc/sys/kernel/powersave-nap
the system will change to NAP running mode.
Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Record the address of the mcount call-site. Currently all archs except sparc64
record the address of the instruction following the mcount call-site. Some
general cleanups are entailed. Storing mcount addresses in rec->ip enables
looking them up in the kprobe hash table later on to check if they're kprobe'd.
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: davem@davemloft.net
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On machines with more than one exception level any system register that
might be modified by the "normal" exception level needs to be saved and
restored on taking a higher level exception. We already are saving
and restoring ESR and DEAR.
For critical level add SRR0/1.
For debug level add CSRR0/1 and SRR0/1.
For machine check level add DSRR0/1, CSRR0/1, and SRR0/1.
On FSL Book-E parts we always save/restore the MAS registers for critical,
debug, and machine check level exceptions. On 44x we always save/restore
the MMUCR.
Additionally, we save and restore the ksp_limit since we have to adjust it
for each exception level.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>
* Cleanup the code a bit my allocating an INT_FRAME on our exception
stack there by make references go from GPR11-INT_FRAME_SIZE(r8) to
just GPR11(r8)
* simplify {lvl}_transfer_to_handler code by moving the copying of the
temp registers we use if we come from user space into the PROLOG
* If the exception came from kernel mode copy thread_info flags,
preempt, and task pointer from the process thread_info.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>