When sequential instruction fetching facility is present,
certain guarantees are provided for code patching. In particular,
atomic overwrites within 8 aligned bytes is safe from an
instruction-fetching point of view.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In the past two save areas existed because interrupt handlers
and system call / program check handlers where entered with
interrupts enabled. To prevent a handler from overwriting the
save areas from the previous handler, interrupts used the async
save area, while system call and program check handler used the
sync save area.
Since the removal of critical section cleanup from entry.S, handlers are
entered with interrupts disabled. When the interrupts are re-enabled,
the save area is no longer need. Therefore merge both save areas into one.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
There is a possibility to deadlock with an recursive
lock of the AP bus scan mutex ap_scan_bus_mutex:
... kernel: ============================================
... kernel: WARNING: possible recursive locking detected
... kernel: 5.14.0-496.el9.s390x #3 Not tainted
... kernel: --------------------------------------------
... kernel: kworker/12:1/130 is trying to acquire lock:
... kernel: 0000000358bc1510 (ap_scan_bus_mutex){+.+.}-{3:3}, at: ap_bus_force_rescan+0x92/0x108
... kernel:
but task is already holding lock:
... kernel: 0000000358bc1510 (ap_scan_bus_mutex){+.+.}-{3:3}, at: ap_scan_bus_wq_callback+0x28/0x60
... kernel:
other info that might help us debug this:
... kernel: Possible unsafe locking scenario:
... kernel: CPU0
... kernel: ----
... kernel: lock(ap_scan_bus_mutex);
... kernel: lock(ap_scan_bus_mutex);
... kernel:
*** DEADLOCK ***
Here is how the callstack looks like:
... [<00000003576fe9ce>] process_one_work+0x2a6/0x748
... [<0000000358150c00>] ap_scan_bus_wq_callback+0x40/0x60 <- mutex locked
... [<00000003581506e2>] ap_scan_bus+0x5a/0x3b0
... [<000000035815037c>] ap_scan_adapter+0x5b4/0x8c0
... [<000000035814fa34>] ap_scan_domains+0x2d4/0x668
... [<0000000357d989b4>] device_add+0x4a4/0x6b8
... [<0000000357d9bb54>] bus_probe_device+0xb4/0xc8
... [<0000000357d9daa8>] __device_attach+0x120/0x1b0
... [<0000000357d9a632>] bus_for_each_drv+0x8a/0xd0
... [<0000000357d9d548>] __device_attach_driver+0xc0/0x140
... [<0000000357d9d3d8>] driver_probe_device+0x40/0xf0
... [<0000000357d9cec2>] really_probe+0xd2/0x460
... [<000000035814d7b0>] ap_device_probe+0x150/0x208
... [<000003ff802a5c46>] zcrypt_cex4_queue_probe+0xb6/0x1c0 [zcrypt_cex4]
... [<000003ff7fb2d36e>] zcrypt_queue_register+0xe6/0x1b0 [zcrypt]
... [<000003ff7fb2c8ac>] zcrypt_rng_device_add+0x94/0xd8 [zcrypt]
... [<0000000357d7bc52>] hwrng_register+0x212/0x228
... [<0000000357d7b8c2>] add_early_randomness+0x102/0x110
... [<000003ff7fb29c94>] zcrypt_rng_data_read+0x94/0xb8 [zcrypt]
... [<0000000358150aca>] ap_bus_force_rescan+0x92/0x108
... [<0000000358177572>] mutex_lock_interruptible_nested+0x32/0x40 <- lock again
Note this only happens when the very first random data providing
crypto card appears via hot plug in the system AND is in disabled
state ("deconfig"). Then the initial pull of random data fails and
a re-scan of the AP bus is triggered while already in the middle
of an AP bus scan caused by the appearing new hardware.
The fix is relatively simple once the scenario us understood:
The AP bus force rescan function will immediately return if there
is currently an AP bus scan running with the very same thread id.
Fixes: eacf5b3651 ("s390/ap: introduce mutex to lock the AP bus scan")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
On newer machines the SHA3 performance of CPACF instructions KIMD and
KLMD can be enhanced by using additional modifier bits. This allows the
application to omit initializing the ICV, but also affects the internal
processing of the instructions. Performance is mostly gained when
processing short messages.
The new CPACF feature is backwards compatible with older machines, i.e.
the new modifier bits are ignored on older machines. However, to save the
ICV initialization, the application must detect the MSA level and omit
the ICV initialization only if this feature is supported.
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Joerg Schmidbauer <jschmidb@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
There is a use case during early boot with an secure key encrypted
root file system where the paes cipher may try to derive a protected
key from secure key while the AP bus is still in the process of
scanning the bus and building up the zcrypt device drivers. As the
detection of CEX cards also triggers the modprobe of the pkey handler
modules, these modules may come into existence too late.
Yet another use case happening during early boot is for use of an
protected key encrypted swap file(system). There is an ephemeral
protected key read via sysfs to set up the swap file. But this only
works when the pkey_pckmo module is already in - which may happen at a
later time as the load is triggered via CPU feature.
This patch introduces a new function pkey_handler_request_modules()
and invokes it which unconditional tries to load in the pkey handler
modules. This function is called for the in-kernel API to derive a
protected key from whatever and in the sysfs API when the first
attempt to simple invoke the handler function failed.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
For some keys there exists an alternative but usually slower
path to convert the key material into a protected key.
This patch introduces a new handler function
slowpath_key_to_protkey()
which provides this alternate path for the CCA and EP11
handler code. With that even the knowledge about how
and when this can be used within the pkey API code can
be removed. So now the pkey API just tries the primary
way and if that fails simple tries the alternative way.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Introduce pkey base kernel code with a simple pkey handler registry.
Regroup the pkey code into these kernel modules:
- pkey is the pkey api supporting the ioctls, sysfs and in-kernel api.
Also the pkey base code which offers the handler registry and
handler wrapping invocation functions is integrated there. This
module is automatically loaded in via CPU feature if the MSA feature
is available.
- pkey-cca is the CCA related handler code kernel module a offering
CCA specific implementation for pkey. This module is loaded in
via MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available.
- pkey-ep11 is the EP11 related handler code kernel module offering an
EP11 specific implementation for pkey. This module is loaded in via
MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available.
- pkey-pckmo is the PCKMO related handler code kernel module. This
module is loaded in via CPU feature if the MSA feature is available,
but on init a check for availability of the pckmo instruction is
performed.
The handler modules register via a pkey_handler struct at the pkey
base code and the pkey customer (that is currently the pkey api code
fetches a handler via pkey handler registry functions and calls the
unified handler functions via the pkey base handler functions.
As a result the pkey-cca, pkey-ep11 and pkey-pckmo modules get
independent from each other and it becomes possible to write new
handlers which offer another kind of implementation without implicit
dependencies to other handler implementations and/or kernel device
drivers.
For each of these 4 kernel modules there is an individual Kconfig
entry: CONFIG_PKEY for the base and api, CONFIG_PKEY_CCA for the PKEY
CCA support handler, CONFIG_PKEY_EP11 for the EP11 support handler and
CONFIG_PKEY_PCKMO for the pckmo support. The both CEX related handler
modules (PKEY CCA and PKEY EP11) have a dependency to the zcrypt api
of the zcrypt device driver.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
As a preparation step for introducing a common function API
between the pkey API module and the handlers (that is the
cca, ep11 and pckmo code) this patch unifies the functions
signatures exposed by the handlers and reworks all the
invocation code of these functions.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This is a huge rework of all the pkey kernel module code.
The goal is to split the code into individual parts with
a dedicated calling interface:
- move all the sysfs related code into pkey_sysfs.c
- all the CCA related code goes to pkey_cca.c
- the EP11 stuff has been moved to pkey_ep11.c
- the PCKMO related code is now in pkey_pckmo.c
The CCA, EP11 and PCKMO code may be seen as "handlers" with
a similar calling interface. The new header file pkey_base.h
declares this calling interface. The remaining code in
pkey_api.c handles the ioctl, the pkey module things and the
"handler" independent code on top of the calling interface
invoking the handlers.
This regrouping of the code will be the base for a real
pkey kernel module split into a pkey base module which acts
as a dispatcher and handler modules providing their service.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Split the very huge ioctl handling function pkey_unlocked_ioctl()
into individual functions per each IOCTL command.
There is no change in functional code coming with this patch.
The work is a simple copy-and-paste with the goal to have
the functionality absolutely untouched.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add new cipher exploiting the full AES-XTS hardware acceleration
introduced with message-security assist extension 10.
The full AES-XTS cipher is registered as preferred cipher in addition
to the discrete AES-XTS variant.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Remove leftover dentry variable after hypfs refactoring.
Before 2fcb3686e1, hypfs_diag.c and other hypfs files were using
debugfs_create_file() explicitly for creating debugfs files and
were storing the returned pointer.
After the refactor, common debugfs file operations and also the
related dentry pointers have been moved into hypfs_dbfs.c and
redefined as new common mechanisms.
Therefore the dentry variable and the debugfs_remove() function
calls in hypfs_diag.c are now redundant.
Current code is not effected since the dentry pointer in
hypfs_diag is implicitly assigned to NULL and debugfs_remove()
returns without an error if the passed pointer is NULL.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Since commit ba05b39d54 ("s390/expoline: Make modules use kernel
expolines"), there is no longer any reason not to use
CONFIG_EXPOLINE_EXTERN when supported by the compiler.
On the positive side:
- there is only a single set of expolines generated and used by both the
kernel code and modules,
- it eliminates expolines "comdat" sections, which can confuse tools
like kpatch.
Always enable EXPOLINE_EXTERN if supported by the compiler.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Over the course of CPU generations a few instructions got extended,
changing their base mnemonic, while keeping the former as an extended
mnemonic. Update the instruction mnemonics in the disassembler to their
latest base mnemonic as documented in the latest IBM z/Architecture
Principles of Operation specification [1].
With the IBM z14 the base mnemonics of the following vector instructions
have been changed:
- Vector FP Load Lengthened (VFLL)
- Vector FP Load Rounded (VFLR)
With Message-Security-Assist Extension 5 Perform Pseudorandom Number
Operation (PPNO) has been renamed to Perform Random Number Operation
(PRNO).
With Vector Enhancements Facility 2 the base mnemonics of the following
vector instructions have been changed:
- Vector FP Convert from Fixed (VCFPS)
- Vector FP Convert from Logical (VCFPL)
- Vector FP Convert to Fixed (VCSFP)
- Vector FP Convert to Logical (VCLFP)
[1] IBM z/Architecture Principles of Operation, SA22-7832-13, IBM z16,
https://publibfp.dhe.ibm.com/epubs/pdf/a227832d.pdf
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Treat register numbers as unsigned. Treat signed operand values as
signed.
This resolves multiple instances of the Cppcheck warning:
warning: %i in format string (no. 1) requires 'int' but the argument
type is 'unsigned int'. [invalidPrintfArgType_sint]
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
ftrace_return_address() is called extremely often from
performance-critical code paths when debugging features like
CONFIG_TRACE_IRQFLAGS are enabled. For example, with debug_defconfig,
ftrace selftests on my LPAR currently execute ftrace_return_address()
as follows:
ftrace_return_address(0) - 0 times (common code uses __builtin_return_address(0) instead)
ftrace_return_address(1) - 2,986,805,401 times (with this patch applied)
ftrace_return_address(2) - 140 times
ftrace_return_address(>2) - 0 times
The use of __builtin_return_address(n) was replaced by return_address()
with an unwinder call by commit cae74ba8c2 ("s390/ftrace:
Use unwinder instead of __builtin_return_address()") because
__builtin_return_address(n) simply walks the stack backchain and doesn't
check for reaching the stack top. For shallow stacks with fewer than
"n" frames, this results in reads at low addresses and random
memory accesses.
While calling the fully functional unwinder "works", it is very slow
for this purpose. Moreover, potentially following stack switches and
walking past IRQ context is simply wrong thing to do for
ftrace_return_address().
Reimplement return_address() to essentially be __builtin_return_address(n)
with checks for reaching the stack top. Since the ftrace_return_address(n)
argument is always a constant, keep the implementation in the header,
allowing both GCC and Clang to unroll the loop and optimize it to the
bare minimum.
Fixes: cae74ba8c2 ("s390/ftrace: Use unwinder instead of __builtin_return_address()")
Cc: stable@vger.kernel.org
Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Since commit 778666df60 ("s390: compile relocatable kernel without
-fPIE") the kernel vmlinux ELF file is linked with --emit-relocs to
preserve all relocations, so that all absolute relocations can be
extracted using the 'relocs' tool to adjust them during boot.
Port and adapt Petr Pavlu's x86 commit 9d9173e9ce ("x86/build: Avoid
relocation information in final vmlinux") to s390 to strip all
relocations from the final vmlinux ELF file to optimize its size.
Following is his original commit message with minor adaptions for s390:
The Linux build process on s390 roughly consists of compiling all input
files, statically linking them into a vmlinux ELF file, and then taking
and turning this file into an actual bzImage bootable file.
vmlinux has in this process two main purposes:
1) It is an intermediate build target on the way to produce the final
bootable image.
2) It is a file that is expected to be used by debuggers and standard
ELF tooling to work with the built kernel.
For the second purpose, a vmlinux file is typically collected by various
package build recipes, such as distribution spec files, including the
kernel's own tar-pkg target.
When building the kernel vmlinux contains also relocation information
produced by using the --emit-relocs linker option. This is utilized by
subsequent build steps to create relocs.S and produce a relocatable
image. However, the information is not needed by debuggers and other
standard ELF tooling.
The issue is then that the collected vmlinux file and hence distribution
packages end up unnecessarily large because of this extra data. The
following is a size comparison of vmlinux v6.10 with and without the
relocation information:
| Configuration | With relocs | Stripped relocs |
| defconfig | 696 MB | 320 MB |
| -CONFIG_DEBUG_INFO | 48 MB | 32 MB |
Optimize a resulting vmlinux by adding a postlink step that splits the
relocation information into relocs.S and then strips it from the vmlinux
binary.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Now that both the kernel modules area and the kernel image itself are
located within 4 GB, there is no longer a need to maintain a separate
ftrace_plt trampoline. Use the existing trampoline in the kernel.
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
If the early program check handler cannot resolve a program check dump
register contents and a call trace to the console before loading a disabled
wait psw. This makes debugging much easier.
Emit an extra message with early_printk() for cases where regular printk()
via the early console is not yet working so that at least some information
is available.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
__do_early_pgm_check() is a function which is only needed during early
setup code. Mark it __init in order to save a few bytes.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Remove WARN_ON_ONCE statements. These have not triggered in the
past.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Rework debug messages:
- Remove most of the debug_sprintf_event() invocations.
- Do not split string format statements
- Remove colon after function name.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
qsi() executes the instruction qsi (query sample information)
and stores the result of the query in a sample information block
pointed to by the function argument. The instruction does not
change the condition code register. The return code is always
zero. No need to check for errors. Remove now unreferenced
macros PMC_FAILURE and RS_INIT_FAILURE_QSI.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
sf_disable() returns the condition code of instruction lsctl (load
sampling controls). However the parameter to lsctl() in
sf_disable() is a sample control block containing
all zeroes. This invocation of lsctl() does not fail and returns
always zero even when there is no authorization for sampling
on the machine. In short, sampling can be always turned off.
Ignore the return code of sf_disable() and change the function
return to void.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The dynamic debugging provides function names on request. So remove
all explicit function strings.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
[dengler: fix indent]
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The dynamic debugging provides function names on request. So remove
all explicit function strings.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The dynamic debugging provides function names on request. So remove
all explicit function strings.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The dynamic debugging provides function names on request. So remove
all explicit function strings.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The dynamic debugging provides function names on request. So remove
all explicit function strings.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Save some bytes and move early_pgm_check_handler() to init text
section.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add missing warning handling to the early program check handler. This
way a warning is printed to the console as soon as the early console
is setup, and the kernel continues to boot.
Before this change a disabled wait psw was loaded instead and the
machine was silently stopped without giving an idea about what
happened.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add the missing pieces so the early program check handler also works
with a relocated lowcore. Right now the result of an early program
check in case of a relocated lowcore would be a program check loop.
Fixes: 8f1e70adb1 ("s390/boot: Add cmdline option to relocate lowcore")
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Have all program check handlers in one file to make future changes easy.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Generate the address marker array dynamically instead of modifying a large
static array at kernel startup. Each marker is added twice to the array:
with and without a "start" indicator. This way the code and logic stays
similar to other architectures.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
All functions but setup_pmc_cpu() use a local variable named
cpuhw to refer to struct cpu_hw_sf.
In setup_pmc_cpu() rename variable cpusf to cpuhw. This makes
the naming scheme consistent with all other functions.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Define and initialize a variable in one place.
Remove space between cast and variable.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The macros PERF_CPUM_CF_MAX_CTR and PERF_EVENT_CPUM_CF_DIAG
are used in only one source file arch/s390/kernel/perf_cpum_cf.c.
Move these defines from the header file
arch/s390/include/asm/perf_event.h to the only user.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Some defines in common header file arch/s390/include/asm/perf_event.h
are only used in one source file arch/s390/kernel/perf_cpum_sf.c.
Move these defines from header to source file.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Rename macro SAMPLE_FREQ_MODE to SAMPL_FREQ_MODE to make its
prefix consistent with all other macro starting with prefix
SAMPL_XXX.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Member hw_perf_event::reg.reg is set but never used, so remove it.
Defines REG_NONE and REG_OVERFLOW are not referenced anymore.
The initialization to zero takes place in function
perf_event_alloc() where
...
event = kmem_cache_alloc_node(perf_event_cache,
GFP_KERNEL | __GFP_ZERO, node);
...
makes sure memory allocated for the event is zero'ed.
This is done in the kernel's common code in kernel/events/core.c
The struct perf_event contains member hw_perf_event as in
struct perf_event {
....
struct hw_perf_event hw;
....
};
This contained sub-structure is also initialized to zero.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The kernel sleep profile is no longer working due to a recursive locking
bug introduced by commit 42a20f86dc ("sched: Add wrapper for get_wchan()
to keep task blocked")
Booting with the 'profile=sleep' kernel command line option added or
executing
# echo -n sleep > /sys/kernel/profiling
after boot causes the system to lock up.
Lockdep reports
kthreadd/3 is trying to acquire lock:
ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: get_wchan+0x32/0x70
but task is already holding lock:
ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x53/0x370
with the call trace being
lock_acquire+0xc8/0x2f0
get_wchan+0x32/0x70
__update_stats_enqueue_sleeper+0x151/0x430
enqueue_entity+0x4b0/0x520
enqueue_task_fair+0x92/0x6b0
ttwu_do_activate+0x73/0x140
try_to_wake_up+0x213/0x370
swake_up_locked+0x20/0x50
complete+0x2f/0x40
kthread+0xfb/0x180
However, since nobody noticed this regression for more than two years,
let's remove 'profile=sleep' support based on the assumption that nobody
needs this functionality.
Fixes: 42a20f86dc ("sched: Add wrapper for get_wchan() to keep task blocked")
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Prevent a deadlock on cpu_hotplug_lock in the aperf/mperf driver.
A recent change in the ACPI code which consolidated code pathes moved
the invocation of init_freq_invariance_cppc() to be moved to a CPU
hotplug handler. The first invocation on AMD CPUs ends up enabling a
static branch which dead locks because the static branch enable tries to
acquire cpu_hotplug_lock but that lock is already held write by the
hotplug machinery.
Use static_branch_enable_cpuslocked() instead and take the hotplug
lock read for the Intel code path which is invoked from the
architecture code outside of the CPU hotplug operations.
- Fix the number of reserved bits in the sev_config structure bit field
so that the bitfield does not exceed 64 bit.
- Add missing Zen5 model numbers
- Fix the alignment assumptions of pti_clone_pgtable() and
clone_entry_text() on 32-bit:
The code assumes PMD aligned code sections, but on 32-bit the kernel
entry text is not PMD aligned. So depending on the code size and
location, which is configuration and compiler dependent, entry text
can cross a PMD boundary. As the start is not PMD aligned adding PMD
size to the start address is larger than the end address which
results in partially mapped entry code for user space. That causes
endless recursion on the first entry from userspace (usually #PF).
Cure this by aligning the start address in the addition so it ends up
at the next PMD start address.
clone_entry_text() enforces PMD mapping, but on 32-bit the tail might
eventually be PTE mapped, which causes a map fail because the PMD for
the tail is not a large page mapping. Use PTI_LEVEL_KERNEL_IMAGE for
the clone() invocation which resolves to PTE on 32-bit and PMD on
64-bit.
- Zero the 8-byte case for get_user() on range check failure on 32-bit
The recend consolidation of the 8-byte get_user() case broke the
zeroing in the failure case again. Establish it by clearing ECX
before the range check and not afterwards as that obvioulsy can't be
reached when the range check fails
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Merge tag 'x86-urgent-2024-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
- Prevent a deadlock on cpu_hotplug_lock in the aperf/mperf driver.
A recent change in the ACPI code which consolidated code pathes moved
the invocation of init_freq_invariance_cppc() to be moved to a CPU
hotplug handler. The first invocation on AMD CPUs ends up enabling a
static branch which dead locks because the static branch enable tries
to acquire cpu_hotplug_lock but that lock is already held write by
the hotplug machinery.
Use static_branch_enable_cpuslocked() instead and take the hotplug
lock read for the Intel code path which is invoked from the
architecture code outside of the CPU hotplug operations.
- Fix the number of reserved bits in the sev_config structure bit field
so that the bitfield does not exceed 64 bit.
- Add missing Zen5 model numbers
- Fix the alignment assumptions of pti_clone_pgtable() and
clone_entry_text() on 32-bit:
The code assumes PMD aligned code sections, but on 32-bit the kernel
entry text is not PMD aligned. So depending on the code size and
location, which is configuration and compiler dependent, entry text
can cross a PMD boundary. As the start is not PMD aligned adding PMD
size to the start address is larger than the end address which
results in partially mapped entry code for user space. That causes
endless recursion on the first entry from userspace (usually #PF).
Cure this by aligning the start address in the addition so it ends up
at the next PMD start address.
clone_entry_text() enforces PMD mapping, but on 32-bit the tail might
eventually be PTE mapped, which causes a map fail because the PMD for
the tail is not a large page mapping. Use PTI_LEVEL_KERNEL_IMAGE for
the clone() invocation which resolves to PTE on 32-bit and PMD on
64-bit.
- Zero the 8-byte case for get_user() on range check failure on 32-bit
The recend consolidation of the 8-byte get_user() case broke the
zeroing in the failure case again. Establish it by clearing ECX
before the range check and not afterwards as that obvioulsy can't be
reached when the range check fails
* tag 'x86-urgent-2024-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/uaccess: Zero the 8-byte get_range case on failure on 32-bit
x86/mm: Fix pti_clone_entry_text() for i386
x86/mm: Fix pti_clone_pgtable() alignment assumption
x86/setup: Parse the builtin command line before merging
x86/CPU/AMD: Add models 0x60-0x6f to the Zen5 range
x86/sev: Fix __reserved field in sev_config
x86/aperfmperf: Fix deadlock on cpu_hotplug_lock
