commit 57fdfbce89137ae85cd5cef48be168040a47dd13 upstream.
Userspace Execution protection and fast syscall entry were implemented
independently from each other and were both merged in kernel 5.2,
leading to syscall entry missing userspace execution protection.
On syscall entry, execution of user space memory must be
locked in the same way as on exception entry.
Fixes: b86fb88855ea ("powerpc/32: implement fast entry for syscalls on non BOOKE")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c65e105b63aaf74f91a14f845bc77192350b84a6.1612796617.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ed5b00a05c2ae95b59adc3442f45944ec632e794 upstream.
The "ibm,arch-vec-5-platform-support" property is a list of pairs of
bytes representing the options and values supported by the platform
firmware. At boot time, Linux scans this list and activates the
available features it recognizes : Radix and XIVE.
A recent change modified the number of entries to loop on and 8 bytes,
4 pairs of { options, values } entries are always scanned. This is
fine on KVM but not on PowerVM which can advertises less. As a
consequence on this platform, Linux reads extra entries pointing to
random data, interprets these as available features and tries to
activate them, leading to a firmware crash in
ibm,client-architecture-support.
Fix that by using the property length of "ibm,arch-vec-5-platform-support".
Fixes: ab91239942a9 ("powerpc/prom: Remove VLA in prom_check_platform_support()")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210122075029.797013-1-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 903178d0ce6bb30ef80a3604ab9ee2b57869fbc9 ]
For unimplemented instructions or unimplemented SPRs, the 8xx triggers
a "Software Emulation Exception" (0x1000). That interrupt doesn't set
reason bits in SRR1 as the "Program Check Exception" does.
Go through emulation_assist_interrupt() to set REASON_ILLEGAL.
Fixes: fbbcc3bb139e ("powerpc/8xx: Remove SoftwareEmulation()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ad782af87a222efc79cfb06079b0fd23d4224eaf.1612515180.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6553896666433e7efec589838b400a2a652b3ffa ]
Some code pathes, especially the low level entry code, must be protected
against instrumentation for various reasons:
- Low level entry code can be a fragile beast, especially on x86.
- With NO_HZ_FULL RCU state needs to be established before using it.
Having a dedicated section for such code allows to validate with tooling
that no unsafe functions are invoked.
Add the .noinstr.text section and the noinstr attribute to mark
functions. noinstr implies notrace. Kprobes will gain a section check
later.
Provide also a set of markers: instrumentation_begin()/end()
These are used to mark code inside a noinstr function which calls
into regular instrumentable text section as safe.
The instrumentation markers are only active when CONFIG_DEBUG_ENTRY is
enabled as the end marker emits a NOP to prevent the compiler from merging
the annotation points. This means the objtool verification requires a
kernel compiled with this option.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134100.075416272@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2225a8dda263edc35a0e8b858fe2945cf6240fde ]
This is a bug that causes early crashes in builds with an .exit.text
section smaller than a page and an .init.text section that ends in the
beginning of a physical page (this is kinda random, which might
explain why this wasn't really encountered before).
The init sections are ordered like this:
.init.text
.exit.text
.init.data
Currently, these sections aren't page aligned.
Because the init code might become read-only at runtime and because
the .init.text section can potentially reside on the same physical
page as .init.data, the beginning of .init.data might be mapped
read-only along with .init.text.
Then when the kernel tries to modify a variable in .init.data (like
kthreadd_done, used in kernel_init()) the kernel panics.
To avoid this, make _einittext page aligned and also align .exit.text
to make sure .init.data is always seperated from the text segments.
Fixes: 060ef9d89d18 ("powerpc32: PAGE_EXEC required for inittext")
Signed-off-by: Ariel Marcovitch <ariel.marcovitch@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210102201156.10805-1-ariel.marcovitch@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fdcfeaba38e5b183045f5b079af94f97658eabe6 ]
Use the common INIT_DATA_SECTION rule for the linker script in an effort
to regularize the linker script.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1604487550-20040-1-git-send-email-tangyouling@loongson.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3ce47d95b7346dcafd9bed3556a8d072cb2b8571 upstream.
Commit eff8728fe698 ("vmlinux.lds.h: Add PGO and AutoFDO input
sections") added ".text.unlikely.*" and ".text.hot.*" due to an LLVM
change [1].
After another LLVM change [2], these sections are seen in some PowerPC
builds, where there is a orphan section warning then build failure:
$ make -skj"$(nproc)" \
ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- LLVM=1 O=out \
distclean powernv_defconfig zImage.epapr
ld.lld: warning: kernel/built-in.a(panic.o):(.text.unlikely.) is being placed in '.text.unlikely.'
...
ld.lld: warning: address (0xc000000000009314) of section .text is not a multiple of alignment (256)
...
ERROR: start_text address is c000000000009400, should be c000000000008000
ERROR: try to enable LD_HEAD_STUB_CATCH config option
ERROR: see comments in arch/powerpc/tools/head_check.sh
...
Explicitly handle these sections like in the main linker script so
there is no more build failure.
[1]: https://reviews.llvm.org/D79600
[2]: https://reviews.llvm.org/D92493
Fixes: 83a092cf95f2 ("powerpc: Link warning for orphan sections")
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1218
Link: https://lore.kernel.org/r/20210104205952.1399409-1-natechancellor@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f10881a46f8914428110d110140a455c66bdf27b upstream.
Commit bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace")
introduced the following error when invoking the errinjct userspace
tool:
[root@ltcalpine2-lp5 librtas]# errinjct open
[327884.071171] sys_rtas: RTAS call blocked - exploit attempt?
[327884.071186] sys_rtas: token=0x26, nargs=0 (called by errinjct)
errinjct: Could not open RTAS error injection facility
errinjct: librtas: open: Unexpected I/O error
The entry for ibm,open-errinjct in rtas_filter array has a typo where
the "j" is omitted in the rtas call name. After fixing this typo the
errinjct tool functions again as expected.
[root@ltcalpine2-lp5 linux]# errinjct open
RTAS error injection facility open, token = 1
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201208195434.8289-1-tyreld@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fe18a35e685c9bdabc8b11b3e19deb85a068b75d ]
Commit 63ce271b5e37 ("powerpc/prom: convert PROM_BUG() to standard
trap") added an EMIT_BUG_ENTRY for the trap after the branch to
start_kernel(). The EMIT_BUG_ENTRY was for the address "0b", however the
trap was not labeled with "0". Hence the address used for bug is in
relative_toc() where the previous "0" label is. Label the trap as "0" so
the correct address is used.
Fixes: 63ce271b5e37 ("powerpc/prom: convert PROM_BUG() to standard trap")
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201130004404.30953-1-jniethe5@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a7223f5bfcaeade4a86d35263493bcda6c940891 ]
Commit 7053f80d9696 ("powerpc/64: Prevent stack protection in early
boot") introduced a couple of uses of __attribute__((optimize)) with
function scope, to disable the stack protector in some early boot
code.
Unfortunately, and this is documented in the GCC man pages [0],
overriding function attributes for optimization is broken, and is only
supported for debug scenarios, not for production: the problem appears
to be that setting GCC -f flags using this method will cause it to
forget about some or all other optimization settings that have been
applied.
So the only safe way to disable the stack protector is to disable it
for the entire source file.
[0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
Fixes: 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
[mpe: Drop one remaining use of __nostackprotector, reported by snowpatch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3c0b976bf20d236c57adcefa80f86a0a1d737727 ]
Currently in generic_secondary_smp_init(), cur_cpu_spec->cpu_restore()
is called before a stack has been set up in r1. This was previously fine
as the cpu_restore() functions were implemented in assembly and did not
use a stack. However commit 5a61ef74f269 ("powerpc/64s: Support new
device tree binding for discovering CPU features") used
__restore_cpu_cpufeatures() as the cpu_restore() function for a
device-tree features based cputable entry. This is a C function and
hence uses a stack in r1.
generic_secondary_smp_init() is entered on the secondary cpus via the
primary cpu using the OPAL call opal_start_cpu(). In OPAL, each hardware
thread has its own stack. The OPAL call is ran in the primary's hardware
thread. During the call, a job is scheduled on a secondary cpu that will
start executing at the address of generic_secondary_smp_init(). Hence
the value that will be left in r1 when the secondary cpu enters the
kernel is part of that secondary cpu's individual OPAL stack. This means
that __restore_cpu_cpufeatures() will write to that OPAL stack. This is
not horribly bad as each hardware thread has its own stack and the call
that enters the kernel from OPAL never returns, but it is still wrong
and should be corrected.
Create the temp kernel stack before calling cpu_restore().
As noted by mpe, for a kexec boot, the secondary CPUs are released from
the spin loop at address 0x60 by smp_release_cpus() and then jump to
generic_secondary_smp_init(). The call to smp_release_cpus() is in
setup_arch(), and it comes before the call to emergency_stack_init().
emergency_stack_init() allocates an emergency stack in the PACA for each
CPU. This address in the PACA is what is used to set up the temp kernel
stack in generic_secondary_smp_init(). Move releasing the secondary CPUs
to after the PACAs have been allocated an emergency stack, otherwise the
PACA stack pointer will contain garbage and hence the temp kernel stack
created from it will be broken.
Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201014072837.24539-1-jniethe5@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 29daf869cbab69088fe1755d9dd224e99ba78b56 upstream.
The kernel expects pte_young() to work regardless of CONFIG_SWAP.
Make sure a minor fault is taken to set _PAGE_ACCESSED when it
is not already set, regardless of the selection of CONFIG_SWAP.
This adds at least 3 instructions to the TLB miss exception
handlers fast path. Following patch will reduce this overhead.
Also update the rotation instruction to the correct number of bits
to reflect all changes done to _PAGE_ACCESSED over time.
Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.")
Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU")
Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits")
Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC")
Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 89a83a0c69c81a25ce91002b90ca27ed86132a0a upstream.
Add a test modelled on the RFI flush test which counts the number
of L1D misses doing a simple syscall with the entry flush on and off.
For simplicity of backporting, this test duplicates a lot of code from
the upstream rfi_flush. This is cleaned up upstream, but we don't clean
it up here because it would involve bringing in even more commits.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9a32a7e78bd0cd9a9b6332cbdc345ee5ffd0c5de upstream.
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache after user accesses.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f79643787e0a0762d2409b7b8334e83f22d85695 upstream.
[backporting note: we need to mark some exception handlers as out-of-line
because the flushing makes them take too much space -- dja]
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache on kernel entry.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 11522448e641e8f1690c9db06e01985e8e19b401 upstream.
The kernel expects pte_young() to work regardless of CONFIG_SWAP.
Make sure a minor fault is taken to set _PAGE_ACCESSED when it
is not already set, regardless of the selection of CONFIG_SWAP.
Fixes: 84de6ab0e904 ("powerpc/603: don't handle PAGE_ACCESSED in TLB miss handlers.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a44367744de54e2315b2f1a8cbbd7f88488072e0.1602342806.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fd552e0542b4532483289cce48fdbd27b692984b ]
Lockdep complains that a possible deadlock below in
eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled,
but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ
disabled. Let's just make eeh_addr_cache_show() acquire the lock with
IRQ disabled as well.
CPU0 CPU1
---- ----
lock(&pci_io_addr_cache_root.piar_lock);
local_irq_disable();
lock(&tp->lock);
lock(&pci_io_addr_cache_root.piar_lock);
<Interrupt>
lock(&tp->lock);
*** DEADLOCK ***
lock_acquire+0x140/0x5f0
_raw_spin_lock_irqsave+0x64/0xb0
eeh_addr_cache_insert_dev+0x48/0x390
eeh_probe_device+0xb8/0x1a0
pnv_pcibios_bus_add_device+0x3c/0x80
pcibios_bus_add_device+0x118/0x290
pci_bus_add_device+0x28/0xe0
pci_bus_add_devices+0x54/0xb0
pcibios_init+0xc4/0x124
do_one_initcall+0xac/0x528
kernel_init_freeable+0x35c/0x3fc
kernel_init+0x24/0x148
ret_from_kernel_thread+0x5c/0x80
lock_acquire+0x140/0x5f0
_raw_spin_lock+0x4c/0x70
eeh_addr_cache_show+0x38/0x110
seq_read+0x1a0/0x660
vfs_read+0xc8/0x1f0
ksys_read+0x74/0x130
system_call_exception+0xf8/0x1d0
system_call_common+0xe8/0x218
Fixes: 5ca85ae6318d ("powerpc/eeh_cache: Add a way to dump the EEH address cache")
Signed-off-by: Qian Cai <cai@redhat.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201028152717.8967-1-cai@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1da4a0272c5469169f78cd76cf175ff984f52f06 upstream.
__get_user_atomic_128_aligned() stores to kaddr using stvx which is a
VMX store instruction, hence kaddr must be 16 byte aligned otherwise
the store won't occur as expected.
Unfortunately when we call __get_user_atomic_128_aligned() in
p9_hmi_special_emu(), the buffer we pass as kaddr (ie. vbuf) isn't
guaranteed to be 16B aligned. This means that the write to vbuf in
__get_user_atomic_128_aligned() has the bottom bits of the address
truncated. This results in other local variables being
overwritten. Also vbuf will not contain the correct data which results
in the userspace emulation being wrong and hence undetected user data
corruption.
In the past we've been mostly lucky as vbuf has ended up aligned but
this is fragile and isn't always true. CONFIG_STACKPROTECTOR in
particular can change the stack arrangement enough that our luck runs
out.
This issue only occurs on POWER9 Nimbus <= DD2.1 bare metal.
The fix is to align vbuf to a 16 byte boundary.
Fixes: 5080332c2c89 ("powerpc/64s: Add workaround for P9 vector CI load issue")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201013043741.743413-1-mikey@neuling.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a02f6d42357acf6e5de6ffc728e6e77faf3ad217 upstream.
It's not done anything for a long time. Save the percpu variable, and
emit a warning to remind users to not expect it to do anything.
This uses pr_warn_once instead of pr_warn_ratelimit as testing
'ppc64_cpu --smt=off' on a 24 core / 4 SMT system showed the warning
to be noisy, as the online/offline loop is slow.
Fixes: 3fa8cad82b94 ("powerpc/pseries/cpuidle: smt-snooze-delay cleanup.")
Cc: stable@vger.kernel.org # v3.14
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902000012.3440389-1-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bd59380c5ba4147dcbaad3e582b55ccfd120b764 upstream.
A number of userspace utilities depend on making calls to RTAS to retrieve
information and update various things.
The existing API through which we expose RTAS to userspace exposes more
RTAS functionality than we actually need, through the sys_rtas syscall,
which allows root (or anyone with CAP_SYS_ADMIN) to make any RTAS call they
want with arbitrary arguments.
Many RTAS calls take the address of a buffer as an argument, and it's up to
the caller to specify the physical address of the buffer as an argument. We
allocate a buffer (the "RMO buffer") in the Real Memory Area that RTAS can
access, and then expose the physical address and size of this buffer in
/proc/powerpc/rtas/rmo_buffer. Userspace is expected to read this address,
poke at the buffer using /dev/mem, and pass an address in the RMO buffer to
the RTAS call.
However, there's nothing stopping the caller from specifying whatever
address they want in the RTAS call, and it's easy to construct a series of
RTAS calls that can overwrite arbitrary bytes (even without /dev/mem
access).
Additionally, there are some RTAS calls that do potentially dangerous
things and for which there are no legitimate userspace use cases.
In the past, this would not have been a particularly big deal as it was
assumed that root could modify all system state freely, but with Secure
Boot and lockdown we need to care about this.
We can't fundamentally change the ABI at this point, however we can address
this by implementing a filter that checks RTAS calls against a list
of permitted calls and forces the caller to use addresses within the RMO
buffer.
The list is based off the list of calls that are used by the librtas
userspace library, and has been tested with a number of existing userspace
RTAS utilities. For compatibility with any applications we are not aware of
that require other calls, the filter can be turned off at build time.
Cc: stable@vger.kernel.org
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200820044512.7543-1-ajd@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5e3119e15fed5b9a9a7e528665ff098a4a8dbdbc ]
According to Freescale's documentation, MPC74XX processors have an
erratum that prevents the TAU interrupt from working, so don't try to
use it when running on those processors.
Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c281611544768e758bd58fe812cf702a5bd2d042.1599260540.git.fthain@telegraphics.com.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 420ab2bc7544d978a5d0762ee736412fe9c796ab ]
The commentary at the call site seems to disagree with the code. The
conditional prevents calling set_thresholds() via the exception handler,
which appears to crash. Perhaps that's because it immediately triggers
another TAU exception. Anyway, calling set_thresholds() from TAUupdate()
is redundant because tau_timeout() does so.
Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d7c7ee33232cf72a6a6bbb6ef05838b2e2b113c0.1599260540.git.fthain@telegraphics.com.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 66943005cc41f48e4d05614e8f76c0ca1812f0fd ]
According to the MPC750 Users Manual, the SITV value in Thermal
Management Register 3 is 13 bits long. The present code calculates the
SITV value as 60 * 500 cycles. This would overflow to give 10 us on
a 500 MHz CPU rather than the intended 60 us. (But according to the
Microprocessor Datasheet, there is also a factor of 266 that has to be
applied to this value on certain parts i.e. speed sort above 266 MHz.)
Always use the maximum cycle count, as recommended by the Datasheet.
Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/896f542e5f0f1d6cf8218524c2b67d79f3d69b3c.1599260540.git.fthain@telegraphics.com.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 265d6e588d87194c2fe2d6c240247f0264e0c19b ]
System Reset and Machine Check interrupts that are not recoverable due
to being nested or interrupting when RI=0 currently panic. This is not
necessary, and can often just kill the current context and recover.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200508043408.886394-16-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4e0942c0302b5ad76b228b1a7b8c09f658a1d58a ]
Many drivers don't check for errors when they get a 0xFFs response from an
MMIO load. As a result after an EEH event occurs a driver can get stuck in
a polling loop unless it some kind of internal timeout logic.
Currently EEH tries to detect and report stuck drivers by dumping a stack
trace after eeh_dev_check_failure() is called EEH_MAX_FAILS times on an
already frozen PE. The value of EEH_MAX_FAILS was chosen so that a dump
would occur every few seconds if the driver was spinning in a loop. This
results in a lot of spurious stack traces in the kernel log.
Fix this by limiting it to printing one stack trace for each PE freeze. If
the driver is truely stuck the kernel's hung task detector is better suited
to reporting the probelm anyway.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191016012536.22588-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 437ef802e0adc9f162a95213a3488e8646e5fc03 upstream.
There are 2 problems with it:
1. "<" vs expected "<<"
2. the shift number is an IOMMU page number mask, not an address
mask as the IOMMU page shift is missing.
This did not hit us before f1565c24b596 ("powerpc: use the generic
dma_ops_bypass mode") because we had additional code to handle bypass
mask so this chunk (almost?) never executed.However there were
reports that aacraid does not work with "iommu=nobypass".
After f1565c24b596, aacraid (and probably others which call
dma_get_required_mask() before setting the mask) was unable to enable
64bit DMA and fall back to using IOMMU which was known not to work,
one of the problems is double free of an IOMMU page.
This fixes DMA for aacraid, both with and without "iommu=nobypass" in
the kernel command line. Verified with "stress-ng -d 4".
Fixes: 6a5c7be5e484 ("powerpc: Override dma_get_required_mask by platform hook and ops")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200908015106.79661-1-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0828137e8f16721842468e33df0460044a0c588b upstream.
__init_FSCR() was added originally in commit 2468dcf641e4 ("powerpc:
Add support for context switching the TAR register") (Feb 2013), and
only set FSCR_TAR.
At that point FSCR (Facility Status and Control Register) was not
context switched, so the setting was permanent after boot.
Later we added initialisation of FSCR_DSCR to __init_FSCR(), in commit
54c9b2253d34 ("powerpc: Set DSCR bit in FSCR setup") (Mar 2013), again
that was permanent after boot.
Then commit 2517617e0de6 ("powerpc: Fix context switch DSCR on
POWER8") (Aug 2013) added a limited context switch of FSCR, just the
FSCR_DSCR bit was context switched based on thread.dscr_inherit. That
commit said "This clears the H/FSCR DSCR bit initially", but it
didn't, it left the initialisation of FSCR_DSCR in __init_FSCR().
However the initial context switch from init_task to pid 1 would clear
FSCR_DSCR because thread.dscr_inherit was 0.
That commit also introduced the requirement that FSCR_DSCR be clear
for user processes, so that we can take the facility unavailable
interrupt in order to manage dscr_inherit.
Then in commit 152d523e6307 ("powerpc: Create context switch helpers
save_sprs() and restore_sprs()") (Dec 2015) FSCR was added to
thread_struct. However it still wasn't fully context switched, we just
took the existing value and set FSCR_DSCR if the new thread had
dscr_inherit set. FSCR was still initialised at boot to FSCR_DSCR |
FSCR_TAR, but that value was not propagated into the thread_struct, so
the initial context switch set FSCR_DSCR back to 0.
Finally commit b57bd2de8c6c ("powerpc: Improve FSCR init and context
switching") (Jun 2016) added a full context switch of the FSCR, and
added an initialisation of init_task.thread.fscr to FSCR_TAR |
FSCR_EBB, but omitted FSCR_DSCR.
The end result is that swapper runs with FSCR_DSCR set because of the
initialisation in __init_FSCR(), but no other processes do, they use
the value from init_task.thread.fscr.
Having FSCR_DSCR set for swapper allows it to access SPR 3 from
userspace, but swapper never runs userspace, so it has no useful
effect. It's also confusing to have the value initialised in two
places to two different values.
So remove FSCR_DSCR from __init_FSCR(), this at least gets us to the
point where there's a single value of FSCR, even if it's still set in
two places.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-1-mpe@ellerman.id.au
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a9f675f950a07d5c1dbcbb97aabac56f5ed085e3 ]
The code in vdso_cpu_init that exposes the cpu and numa node to
userspace via SPRG_VDSO incorrctly masks the cpu to 12 bits. This means
that any kernel running on a box with more than 4096 threads (NR_CPUS
advertises a limit of of 8192 cpus) would expose userspace to two cpu
contexts running at the same time with the same cpu number.
Note: I'm not aware of any distro shipping a kernel with support for more
than 4096 threads today, nor of any system image that currently exceeds
4096 threads. Found via code browsing.
Fixes: 18ad51dd342a7eb09dbcd059d0b451b616d4dafc ("powerpc: Add VDSO version of getcpu")
Signed-off-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200715233704.1352257-1-anton@ozlabs.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec2fc2a9e9bbad9023aab65bc472ce7a3ca8608f ]
Partition suspension, used for hibernation and migration, requires
that the OS place all but one of the LPAR's processor threads into one
of two states prior to calling the ibm,suspend-me RTAS function:
* the architected offline state (via RTAS stop-self); or
* the H_JOIN hcall, which does not return until the partition
resumes execution
Using H_CEDE as the offline mode, introduced by
commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into
an appropriate offline state"), means that any threads which are
offline from Linux's point of view must be moved to one of those two
states before a partition suspension can proceed.
This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring
all threads online prior to migration/hibernation"), which added code
to temporarily bring up any offline processor threads so they can call
H_JOIN. Conceptually this is fine, but the implementation has had
multiple races with cpu hotplug operations initiated from user
space[1][2][3], the error handling is fragile, and it generates
user-visible cpu hotplug events which is a lot of noise for a platform
feature that's supposed to minimize disruption to workloads.
With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU
into an appropriate offline state") reverted, this code becomes
unnecessary, so remove it. Since any offline CPUs now are truly
offline from the platform's point of view, it is no longer necessary
to bring up CPUs only to have them call H_JOIN and then go offline
again upon resuming. Only active threads are required to call H_JOIN;
stopped threads can be left alone.
[1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and
serialization during LPM")
[2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races
with suspend/migration")
[3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between
CPU-Offline & Migration")
Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b710d27bf72068b15b2f0305d825988183e2ff28 upstream.
Early secure guest boot hits the below crash while booting with
vcpus numbers aligned with page boundary for PAGE size of 64k
and LPPACA size of 1k i.e 64, 128 etc.
Partition configured for 64 cpus.
CPU maps initialized for 1 thread per core
------------[ cut here ]------------
kernel BUG at arch/powerpc/kernel/paca.c:89!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
This is due to the BUG_ON() for shared_lppaca_total_size equal to
shared_lppaca_size. Instead the code should only BUG_ON() if we have
exceeded the total_size, which indicates we've overflowed the array.
Fixes: bd104e6db6f0 ("powerpc/pseries/svm: Use shared memory for LPPACA structures")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
[mpe: Reword change log to clarify we're fixing not removing the check]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200619070113.16696-1-sathnaga@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a6e2c226c3d51fd93636320e47cabc8a8f0824c5 ]
With CONFIG_DEBUG_VIRTUAL=y, we can hit a BUG() if we take a hard
lockup watchdog interrupt when in OPAL mode.
This happens in show_instructions() if the kernel takes the watchdog
NMI IPI, or any other interrupt, with MSR_IR == 0. show_instructions()
updates the variable pc in the loop and the second iteration will
result in BUG().
We hit the BUG_ON due the below check in __va()
#define __va(x)
({
VIRTUAL_BUG_ON((unsigned long)(x) >= PAGE_OFFSET);
(void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET);
})
Fix it by moving the check out of the loop. Also update nip so that
the nip == pc check still matches.
Fixes: 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Use IS_ENABLED(), massage change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200524093822.423487-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8a5054d8cbbe03c68dcb0957c291c942132e4101 ]
The architecture allows for machine check exceptions to cause idle
wakeups which resume at the 0x200 address which has to return via
the idle wakeup code, but the early machine check handler is run
first.
The case of a no state-loss sleep is broken because the early
handler uses non-volatile register r1 , which is needed for the wakeup
protocol, but it is not restored.
Fix this by loading r1 from the MCE exception frame before returning
to the idle wakeup code. Also update the comment which has become
stale since the idle rewrite in C.
This crash was found and fix confirmed with a machine check injection
test in qemu powernv model (which is not upstream in qemu yet).
Fixes: 10d91611f426d ("powerpc/64s: Reimplement book3s idle code in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200508043408.886394-2-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ffa8b7dc11752827329e4e84a574ea6aaf24716 ]
Aneesh increased the size of struct pt_regs by 16 bytes and started
seeing this WARN_ON:
smp: Bringing up secondary CPUs ...
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at arch/powerpc/kernel/process.c:455 giveup_all+0xb4/0x110
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+ #318
NIP: c00000000001a2b4 LR: c00000000001a29c CTR: c0000000031d0000
REGS: c0000000026d3980 TRAP: 0700 Not tainted (5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+)
MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 48048224 XER: 00000000
CFAR: c000000000019cc8 IRQMASK: 1
GPR00: c00000000001a264 c0000000026d3c20 c0000000026d7200 800000000280b033
GPR04: 0000000000000001 0000000000000000 0000000000000077 30206d7372203164
GPR08: 0000000000002000 0000000002002000 800000000280b033 3230303030303030
GPR12: 0000000000008800 c0000000031d0000 0000000000800050 0000000002000066
GPR16: 000000000309a1a0 000000000309a4b0 000000000309a2d8 000000000309a890
GPR20: 00000000030d0098 c00000000264da40 00000000fd620000 c0000000ff798080
GPR24: c00000000264edf0 c0000001007469f0 00000000fd620000 c0000000020e5e90
GPR28: c00000000264edf0 c00000000264d200 000000001db60000 c00000000264d200
NIP [c00000000001a2b4] giveup_all+0xb4/0x110
LR [c00000000001a29c] giveup_all+0x9c/0x110
Call Trace:
[c0000000026d3c20] [c00000000001a264] giveup_all+0x64/0x110 (unreliable)
[c0000000026d3c90] [c00000000001ae34] __switch_to+0x104/0x480
[c0000000026d3cf0] [c000000000e0b8a0] __schedule+0x320/0x970
[c0000000026d3dd0] [c000000000e0c518] schedule_idle+0x38/0x70
[c0000000026d3df0] [c00000000019c7c8] do_idle+0x248/0x3f0
[c0000000026d3e70] [c00000000019cbb8] cpu_startup_entry+0x38/0x40
[c0000000026d3ea0] [c000000000011bb0] rest_init+0xe0/0xf8
[c0000000026d3ed0] [c000000002004820] start_kernel+0x990/0x9e0
[c0000000026d3f90] [c00000000000c49c] start_here_common+0x1c/0x400
Which was unexpected. The warning is checking the thread.regs->msr
value of the task we are switching from:
usermsr = tsk->thread.regs->msr;
...
WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
ie. if MSR_VSX is set then both of MSR_FP and MSR_VEC are also set.
Dumping tsk->thread.regs->msr we see that it's: 0x1db60000
Which is not a normal looking MSR, in fact the only valid bit is
MSR_VSX, all the other bits are reserved in the current definition of
the MSR.
We can see from the oops that it was swapper/0 that we were switching
from when we hit the warning, ie. init_task. So its thread.regs points
to the base (high addresses) in init_stack.
Dumping the content of init_task->thread.regs, with the members of
pt_regs annotated (the 16 bytes larger version), we see:
0000000000000000 c000000002780080 gpr[0] gpr[1]
0000000000000000 c000000002666008 gpr[2] gpr[3]
c0000000026d3ed0 0000000000000078 gpr[4] gpr[5]
c000000000011b68 c000000002780080 gpr[6] gpr[7]
0000000000000000 0000000000000000 gpr[8] gpr[9]
c0000000026d3f90 0000800000002200 gpr[10] gpr[11]
c000000002004820 c0000000026d7200 gpr[12] gpr[13]
000000001db60000 c0000000010aabe8 gpr[14] gpr[15]
c0000000010aabe8 c0000000010aabe8 gpr[16] gpr[17]
c00000000294d598 0000000000000000 gpr[18] gpr[19]
0000000000000000 0000000000001ff8 gpr[20] gpr[21]
0000000000000000 c00000000206d608 gpr[22] gpr[23]
c00000000278e0cc 0000000000000000 gpr[24] gpr[25]
000000002fff0000 c000000000000000 gpr[26] gpr[27]
0000000002000000 0000000000000028 gpr[28] gpr[29]
000000001db60000 0000000004750000 gpr[30] gpr[31]
0000000002000000 000000001db60000 nip msr
0000000000000000 0000000000000000 orig_r3 ctr
c00000000000c49c 0000000000000000 link xer
0000000000000000 0000000000000000 ccr softe
0000000000000000 0000000000000000 trap dar
0000000000000000 0000000000000000 dsisr result
0000000000000000 0000000000000000 ppr kuap
0000000000000000 0000000000000000 pad[2] pad[3]
This looks suspiciously like stack frames, not a pt_regs. If we look
closely we can see return addresses from the stack trace above,
c000000002004820 (start_kernel) and c00000000000c49c (start_here_common).
init_task->thread.regs is setup at build time in processor.h:
#define INIT_THREAD { \
.ksp = INIT_SP, \
.regs = (struct pt_regs *)INIT_SP - 1, /* XXX bogus, I think */ \
The early boot code where we setup the initial stack is:
LOAD_REG_ADDR(r3,init_thread_union)
/* set up a stack pointer */
LOAD_REG_IMMEDIATE(r1,THREAD_SIZE)
add r1,r3,r1
li r0,0
stdu r0,-STACK_FRAME_OVERHEAD(r1)
Which creates a stack frame of size 112 bytes (STACK_FRAME_OVERHEAD).
Which is far too small to contain a pt_regs.
So the result is init_task->thread.regs is pointing at some stack
frames on the init stack, not at a pt_regs.
We have gotten away with this for so long because with pt_regs at its
current size the MSR happens to point into the first frame, at a
location that is not written to by the early asm. With the 16 byte
expansion the MSR falls into the second frame, which is used by the
compiler, and collides with a saved register that tends to be
non-zero.
As far as I can see this has been wrong since the original merge of
64-bit ppc support, back in 2002.
Conceptually swapper should have no regs, it never entered from
userspace, and in fact that's what we do on 32-bit. It's also
presumably what the "bogus" comment is referring to.
So I think the right fix is to just not-initialise regs at all. I'm
slightly worried this will break some code that isn't prepared for a
NULL regs, but we'll have to see.
Remove the comment in head_64.S which refers to us setting up the
regs (even though we never did), and is otherwise not really accurate
any more.
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200428123130.73078-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit be5470e0c285a68dc3afdea965032f5ddc8269d7 ]
'mem=" option is an easy way to put high pressure on memory during
some test. Hence after applying the memory limit, instead of total
mem, the actual usable memory should be considered when reserving mem
for crashkernel. Otherwise the boot up may experience OOM issue.
E.g. it would reserve 4G prior to the change and 512M afterward, if
passing
crashkernel="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G",
and mem=5G on a 256G machine.
This issue is powerpc specific because it puts higher priority on
fadump and kdump reservation than on "mem=". Referring the following
code:
if (fadump_reserve_mem() == 0)
reserve_crashkernel();
...
/* Ensure that total memory size is page-aligned. */
limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE);
memblock_enforce_memory_limit(limit);
While on other arches, the effect of "mem=" takes a higher priority
and pass through memblock_phys_mem_size() before calling
reserve_crashkernel().
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1585749644-4148-1-git-send-email-kernelfans@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 912c0a7f2b5daa3cbb2bc10f303981e493de73bd upstream.
At boot the FSCR is initialised via one of two paths. On most systems
it's set to a hard coded value in __init_FSCR().
On newer skiboot systems we use the device tree CPU features binding,
where firmware can tell Linux what bits to set in FSCR (and HFSCR).
In both cases the value that's configured at boot is not propagated
into the init_task.thread.fscr value prior to the initial fork of init
(pid 1), which means the value is not used by any processes other than
swapper (the idle task).
For the __init_FSCR() case this is OK, because the value in
init_task.thread.fscr is initialised to something sensible. However it
does mean that the value set in __init_FSCR() is not used other than
for swapper, which is odd and confusing.
The bigger problem is for the device tree CPU features case it
prevents firmware from setting (or clearing) FSCR bits for use by user
space. This means all existing kernels can not have features
enabled/disabled by firmware if those features require
setting/clearing FSCR bits.
We can handle both cases by saving the FSCR value into
init_task.thread.fscr after we have initialised it at boot. This fixes
the bug for device tree CPU features, and will allow us to simplify
the initialisation for the __init_FSCR() case in a future patch.
Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-3-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 993e3d96fd08c3ebf7566e43be9b8cd622063e6d upstream.
The device tree CPU features binding includes FSCR bit numbers which
Linux is instructed to set by firmware.
Whether that's a good idea or not, in the case of the DSCR the Linux
implementation has a hard requirement that the FSCR_DSCR bit not be
set by default. We use it to track when a process reads/writes to
DSCR, so it must be clear to begin with.
So if firmware tells us to set FSCR_DSCR we must ignore it.
Currently this does not cause a bug in our DSCR handling because the
value of FSCR that the device tree CPU features code establishes is
only used by swapper. All other tasks use the value hard coded in
init_task.thread.fscr.
However we'd like to fix that in a future commit, at which point this
will become necessary.
Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-2-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9a2921e5baca1d25eb8d21f21d1e90581a6d0f68 upstream.
If the memory chunk found for reserving memory overshoots the memory
limit imposed, do not proceed with reserving memory. Default behavior
was this until commit 140777a3d8df ("powerpc/fadump: consider reserved
ranges while reserving memory") changed it unwittingly.
Fixes: 140777a3d8df ("powerpc/fadump: consider reserved ranges while reserving memory")
Cc: stable@vger.kernel.org
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159057266320.22331.6571453892066907320.stgit@hbathini.in.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 140777a3d8dfdb3d3f20ea7707c0f1c0ce1b0aa5 upstream.
Commit 0962e8004e97 ("powerpc/prom: Scan reserved-ranges node for
memory reservations") enabled support to parse reserved-ranges DT
node and reserve kernel memory falling in these ranges for F/W
purposes. Memory reserved for FADump should not overlap with these
ranges as it could corrupt memory meant for F/W or crash'ed kernel
memory to be exported as vmcore.
But since commit 579ca1a27675 ("powerpc/fadump: make use of memblock's
bottom up allocation mode"), memblock_find_in_range() is being used to
find the appropriate area to reserve memory for FADump, which can't
account for reserved-ranges as these ranges are reserved only after
FADump memory reservation.
With reserved-ranges now being populated during early boot, look out
for these memory ranges while reserving memory for FADump. Without
this change, MPIPL on PowerNV systems aborts with hostboot failure,
when memory reserved for FADump is less than 4096MB.
Fixes: 579ca1a27675 ("powerpc/fadump: make use of memblock's bottom up allocation mode")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/158737297693.26700.16193820746269425424.stgit@hbathini.in.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 02c04e374e176ae3a3f64a682f80702f8d2fb65d upstream.
At times, memory ranges have to be looked up during early boot, when
kernel couldn't be initialized for dynamic memory allocation. In fact,
reserved-ranges look up is needed during FADump memory reservation.
Without accounting for reserved-ranges in reserving memory for FADump,
MPIPL boot fails with memory corruption issues. So, extend memory
ranges handling to support static allocation and populate reserved
memory ranges during early boot.
Fixes: dda9dbfeeb7a ("powerpc/fadump: consider reserved ranges while releasing memory")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/158737294432.26700.4830263187856221314.stgit@hbathini.in.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 90ceddcb495008ac8ba7a3dce297841efcd7d584 upstream.
Simplify gen_btf logic to make it work with llvm-objcopy. The existing
'file format' and 'architecture' parsing logic is brittle and does not
work with llvm-objcopy/llvm-objdump.
'file format' output of llvm-objdump>=11 will match GNU objdump, but
'architecture' (bfdarch) may not.
.BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag
because it is part of vmlinux image used for introspection. C code
can reference the section via linker script defined __start_BTF and
__stop_BTF. This fixes a small problem that previous .BTF had the
SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data).
Additionally, `objcopy -I binary` synthesized symbols
_binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not
used elsewhere) are replaced with more commonplace __start_BTF and
__stop_BTF.
Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns
"empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?"
We use a dd command to change the e_type field in the ELF header from
ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o. Accepting
ET_EXEC as an input file is an extremely rare GNU ld feature that lld
does not intend to support, because this is error-prone.
The output section description .BTF in include/asm-generic/vmlinux.lds.h
avoids potential subtle orphan section placement issues and suppresses
--orphan-handling=warn warnings.
Fixes: df786c9b9476 ("bpf: Force .BTF section start to zero when dumping from vmlinux")
Fixes: cb0cc635c7a9 ("powerpc: Include .BTF section")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Stanislav Fomichev <sdf@google.com>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://github.com/ClangBuiltLinux/linux/issues/871
Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com
Signed-off-by: Maria Teguiani <teguiani@google.com>
Tested-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit feb8e960d780e170e992a70491eec9dd68f4dbf2 upstream.
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: e2fb9f544431 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 94c0b013c98583614e1ad911e8795ca36da34a85 upstream.
If {i,d}-cache-block-size is set and {i,d}-cache-line-size is not, use
the block-size value for both. Per the devicetree spec cache-line-size
is only needed if it differs from the block size.
Originally the code would fallback from block size to line size. An
error message was printed if both properties were missing.
Later the code was refactored to use clearer names and logic but it
inadvertently made line size a required property, meaning on systems
without a line size property we fall back to the default from the
cputable.
On powernv (OPAL) platforms, since the introduction of device tree CPU
features (5a61ef74f269 ("powerpc/64s: Support new device tree binding
for discovering CPU features")), that has led to the wrong value being
used, as the fallback value is incorrect for Power8/Power9 CPUs.
The incorrect values flow through to the VDSO and also to the sysconf
values, SC_LEVEL1_ICACHE_LINESIZE etc.
Fixes: bd067f83b084 ("powerpc/64: Fix naming of cache block vs. cache line")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reported-by: Qian Cai <cai@lca.pw>
[mpe: Add even more detail to change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200416221908.7886-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit abc3fce76adbdfa8f87272c784b388cd20b46049 ]
This reverts commit ebb37cf3ffd39fdb6ec5b07111f8bb2f11d92c5f.
That commit does not play well with soft-masked irq state
manipulations in idle, interrupt replay, and possibly others due to
tracing code sometimes using irq_work_queue (e.g., in
trace_hardirqs_on()). That can cause PACA_IRQ_DEC to become set when
it is not expected, and be ignored or cleared or cause warnings.
The net result seems to be missing an irq_work until the next timer
interrupt in the worst case which is usually not going to be noticed,
however it could be a long time if the tick is disabled, which is
against the spirit of irq_work and might cause real problems.
The idea is still solid, but it would need more work. It's not really
clear if it would be worth added complexity, so revert this for
now (not a straight revert, but replace with a comment explaining why
we might see interrupts happening, and gives git blame something to
find).
Fixes: ebb37cf3ffd3 ("powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402120401.1115883-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 74bb84e5117146fa73eb9d01305975c53022b3c3 ]
The "os-term" RTAS calls has one argument with a message address of OS
termination cause. rtas_os_term() already passes it but the recently
added prom_init's version of that missed it; it also does not fill
args correctly.
This passes the message address and initializes the number of arguments.
Fixes: 6a9c930bd775 ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200312074404.87293-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 upstream.
Declaring setjmp()/longjmp() as taking longs makes the signature
non-standard, and makes clang complain. In the past, this has been
worked around by adding -ffreestanding to the compile flags.
The implementation looks like it only ever propagates the value
(in longjmp) or sets it to 1 (in setjmp), and we only call longjmp
with integer parameters.
This allows removing -ffreestanding from the compilation flags.
Fixes: c9029ef9c957 ("powerpc: Avoid clang warnings around setjmp and longjmp")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Clement Courbet <courbet@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@google.com
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7053f80d96967d8e72e9f2a724bbfc3906ce2b07 upstream.
The previous commit reduced the amount of code that is run before we
setup a paca. However there are still a few remaining functions that
run with no paca, or worse, with an arbitrary value in r13 that will
be used as a paca pointer.
In particular the stack protector canary is stored in the paca, so if
stack protector is activated for any of these functions we will read
the stack canary from wherever r13 points. If r13 happens to point
outside of memory we will get a machine check / checkstop.
For example if we modify initialise_paca() to trigger stack
protection, and then boot in the mambo simulator with r13 poisoned in
skiboot before calling the kernel:
DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis r2,r12,0x6D [fetch]
DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr r12 [fetch]
FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off
DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld r8,0xCF8(r13) [Instruction Failed]
INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop, **
systemsim % bt
pc: 0xC0000000191FCA7C initialise_paca+0x54
lr: 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBED0 0x0 +0x0
stack:0x00000000198CBF00 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBF90 0x1801C968 +0x1801C968
So annotate the relevant functions to ensure stack protection is never
enabled for them.
Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-2-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Christophe Leroy