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Add struct ctlreg to enforce strict type checking / usage for control
register functions.
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>
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Open code struct per_regs within kprobes and ptrace code, since at both
locations a struct per_regs is passed to __local_ctl_load() and
__local_ctl_store() which prevents to implement type checking for both
functions.
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>
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Change __local_ctl_load() and __local_ctl_store(), so that control
register parameters come first.
This way all control handling functions consistently have control
register(s) parameter first.
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>
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Add local and system prefix to some functions to clarify they change
control register contents on either the local CPU or the on all CPUs.
This results in the following API:
Two defines which load and save multiple control registers.
The defines correlate with the following C prototypes:
void __local_ctl_load(unsigned long *, unsigned int cr_low, unsigned int cr_high);
void __local_ctl_store(unsigned long *, unsigned int cr_low, unsigned int cr_high);
Two functions which locally set or clear one bit for a specified
control register:
void local_ctl_set_bit(unsigned int cr, unsigned int bit);
void local_ctl_clear_bit(unsigned int cr, unsigned int bit);
Two functions which set or clear one bit for a specified control
register on all CPUs:
void system_ctl_set_bit(unsigned int cr, unsigned int bit);
void system_ctl_clear_bit(unsigend int cr, unsigned int bit);
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>
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Given that set_memory_rox() and set_memory_rwnx() exist, it is possible
to get rid of all open coded __set_memory() usages and replace them with
proper helper calls everywhere.
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>
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Recent test_kprobe_missed kprobes kunit test uncovers the following
problem. Once kprobe is triggered from another kprobe (kprobe reenter),
all future kprobes on this cpu are considered as kprobe reenter, thus
pre_handler and post_handler are not being called and kprobes are counted
as "missed".
Commit b9599798f953 ("[S390] kprobes: activation and deactivation")
introduced a simpler scheme for kprobes (de)activation and status
tracking by using push_kprobe/pop_kprobe, which supposed to work for
both initial kprobe entry as well as kprobe reentry and helps to avoid
handling those two cases differently. The problem is that a sequence of
calls in case of kprobes reenter:
push_kprobe() <- NULL (current_kprobe)
push_kprobe() <- kprobe1 (current_kprobe)
pop_kprobe() -> kprobe1 (current_kprobe)
pop_kprobe() -> kprobe1 (current_kprobe)
leaves "kprobe1" as "current_kprobe" on this cpu, instead of setting it
to NULL. In fact push_kprobe/pop_kprobe can only store a single state
(there is just one prev_kprobe in kprobe_ctlblk). Which is a hack but
sufficient, there is no need to have another prev_kprobe just to store
NULL. To make a simple and backportable fix simply reset "prev_kprobe"
when kprobe is poped from this "stack". No need to worry about
"kprobe_status" in this case, because its value is only checked when
current_kprobe != NULL.
Cc: stable@vger.kernel.org
Fixes: b9599798f953 ("[S390] kprobes: activation and deactivation")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Recent test_kprobe_missed kprobes kunit test uncovers the following error
(reported when CONFIG_DEBUG_ATOMIC_SLEEP is enabled):
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 662, name: kunit_try_catch
preempt_count: 0, expected: 0
RCU nest depth: 0, expected: 0
no locks held by kunit_try_catch/662.
irq event stamp: 280
hardirqs last enabled at (279): [<00000003e60a3d42>] __do_pgm_check+0x17a/0x1c0
hardirqs last disabled at (280): [<00000003e3bd774a>] kprobe_exceptions_notify+0x27a/0x318
softirqs last enabled at (0): [<00000003e3c5c890>] copy_process+0x14a8/0x4c80
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 46 PID: 662 Comm: kunit_try_catch Tainted: G N 6.2.0-173644-g44c18d77f0c0 #2
Hardware name: IBM 3931 A01 704 (LPAR)
Call Trace:
[<00000003e60a3a00>] dump_stack_lvl+0x120/0x198
[<00000003e3d02e82>] __might_resched+0x60a/0x668
[<00000003e60b9908>] __mutex_lock+0xc0/0x14e0
[<00000003e60bad5a>] mutex_lock_nested+0x32/0x40
[<00000003e3f7b460>] unregister_kprobe+0x30/0xd8
[<00000003e51b2602>] test_kprobe_missed+0xf2/0x268
[<00000003e51b5406>] kunit_try_run_case+0x10e/0x290
[<00000003e51b7dfa>] kunit_generic_run_threadfn_adapter+0x62/0xb8
[<00000003e3ce30f8>] kthread+0x2d0/0x398
[<00000003e3b96afa>] __ret_from_fork+0x8a/0xe8
[<00000003e60ccada>] ret_from_fork+0xa/0x40
The reason for this error report is that kprobes handling code failed
to restore irqs.
The problem is that when kprobe is triggered from another kprobe
post_handler current sequence of enable_singlestep / disable_singlestep
is the following:
enable_singlestep <- original kprobe (saves kprobe_saved_imask)
enable_singlestep <- kprobe triggered from post_handler (clobbers kprobe_saved_imask)
disable_singlestep <- kprobe triggered from post_handler (restores kprobe_saved_imask)
disable_singlestep <- original kprobe (restores wrong clobbered kprobe_saved_imask)
There is just one kprobe_ctlblk per cpu and both calls saves and
loads irq mask to kprobe_saved_imask. To fix the problem simply move
resume_execution (which calls disable_singlestep) before calling
post_handler. This also fixes the problem that post_handler is called
with pt_regs which were not yet adjusted after single-stepping.
Cc: stable@vger.kernel.org
Fixes: 4ba069b802c2 ("[S390] add kprobes support.")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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That's an adaptation of commit f3a112c0c40d ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86") to s390.
Replaces the kretprobe code with rethook on s390. With this patch,
kretprobe on s390 uses the rethook instead of kretprobe specific
trampoline code.
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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clang warns about an unused insn cache ops function:
arch/s390/kernel/kprobes.c:34:1:
error: unused function 'is_kprobe_s390_insn_slot' [-Werror,-Wunused-function]
DEFINE_INSN_CACHE_OPS(s390_insn);
^
./include/linux/kprobes.h:335:20: note: expanded from macro 'DEFINE_INSN_CACHE_OPS'
static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
^
<scratch space>:88:1: note: expanded from here
is_kprobe_s390_insn_slot
^
Move the definition to a private header file, which is also similar to
the generic insn cache ops.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Use regs->gprs[15] for framepointer verification. This enables
additional sanity checks for nested kretprobes.
Reviewed-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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So far, s390 registered a krobe on __kretprobe_trampoline which is
called everytime a kretprobe fires. This kprobe would then determine
the correct return address and adjust the psw accordingly, such that
the kretprobe would branch to the appropriate address after completion.
Some other archs handle kretprobes without such an additional kprobe.
This approach is adopted to s390 with this patch.
Furthermore, the __kretprobe_trampoline now uses an assembler function
to correctly gather the register and psw content to be passed to the
registered kretprobe handler as struct pt_regs. After completion, the
register content and the psw are set based on the contents of said
pt_regs struct.
Note that a change to the psw address in struct pt_regs will not have
an impact, as the probe will still return to the original return
address of the probed function.
The return address is now recovered by using the appropriate function
arch_kretprobe_fixup_return.
The no longer needed kprobe is removed.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Add and use fixup_exception helper function in order to remove the
duplicated exception handler fixup code at several places.
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>
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:
- Add support for ftrace with direct call and ftrace direct call
samples.
- Add support for kernel command lines longer than current 896 bytes
and make its length configurable.
- Add support for BEAR enhancement facility to improve last breaking
event instruction tracking.
- Add kprobes sanity checks and testcases to prevent kprobe in the mid
of an instruction.
- Allow concurrent access to /dev/hwc for the CPUMF users.
- Various ftrace / jump label improvements.
- Convert unwinder tests to KUnit.
- Add s390_iommu_aperture kernel parameter to tweak the limits on
concurrently usable DMA mappings.
- Add ap.useirq AP module option which can be used to disable interrupt
use.
- Add add_disk() error handling support to block device drivers.
- Drop arch specific and use generic implementation of strlcpy and
strrchr.
- Several __pa/__va usages fixes.
- Various cio, crypto, pci, kernel doc and other small fixes and
improvements all over the code.
[ Merge fixup as per https://lore.kernel.org/all/YXAqZ%2FEszRisunQw@osiris/ ]
* tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (63 commits)
s390: make command line configurable
s390: support command lines longer than 896 bytes
s390/kexec_file: move kernel image size check
s390/pci: add s390_iommu_aperture kernel parameter
s390/spinlock: remove incorrect kernel doc indicator
s390/string: use generic strlcpy
s390/string: use generic strrchr
s390/ap: function rework based on compiler warning
s390/cio: make ccw_device_dma_* more robust
s390/vfio-ap: s390/crypto: fix all kernel-doc warnings
s390/hmcdrv: fix kernel doc comments
s390/ap: new module option ap.useirq
s390/cpumf: Allow multiple processes to access /dev/hwc
s390/bitops: return true/false (not 1/0) from bool functions
s390: add support for BEAR enhancement facility
s390: introduce nospec_uses_trampoline()
s390: rename last_break to pgm_last_break
s390/ptrace: add last_break member to pt_regs
s390/sclp: sort out physical vs virtual pointers usage
s390/setup: convert start and end initrd pointers to virtual
...
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Check whether the specified address points to the start of an
instruction to prevent users from setting a kprobe in the mid of
an instruction which would crash the kernel.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Since now there is kretprobe_trampoline_addr() for referring the
address of kretprobe trampoline code, we don't need to access
kretprobe_trampoline directly.
Make it harder to refer by renaming it to __kretprobe_trampoline().
Link: https://lkml.kernel.org/r/163163045446.489837.14510577516938803097.stgit@devnote2
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The __kretprobe_trampoline_handler() callback, called from low level
arch kprobes methods, has the 'trampoline_address' parameter, which is
entirely superfluous as it basically just replicates:
dereference_kernel_function_descriptor(kretprobe_trampoline)
In fact we had bugs in arch code where it wasn't replicated correctly.
So remove this superfluous parameter and use kretprobe_trampoline_addr()
instead.
Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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This clean up the error/notification messages in kprobes related code.
Basically this defines 'pr_fmt()' macros for each files and update
the messages which describes
- what happened,
- what is the kernel going to do or not do,
- is the kernel fine,
- what can the user do about it.
Also, if the message is not needed (e.g. the function returns unique
error code, or other error message is already shown.) remove it,
and replace the message with WARN_*() macros if suitable.
Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Use is_kernel() helper instead of is_kernel_addr().
[hca@linux.ibm.com: add missing unsigned long cast]
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Merge more updates from Andrew Morton:
"190 patches.
Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
signals, exec, kcov, selftests, compress/decompress, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
ipc/util.c: use binary search for max_idx
ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
ipc: use kmalloc for msg_queue and shmid_kernel
ipc sem: use kvmalloc for sem_undo allocation
lib/decompressors: remove set but not used variabled 'level'
selftests/vm/pkeys: exercise x86 XSAVE init state
selftests/vm/pkeys: refill shadow register after implicit kernel write
selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
kcov: add __no_sanitize_coverage to fix noinstr for all architectures
exec: remove checks in __register_bimfmt()
x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
hfsplus: report create_date to kstat.btime
hfsplus: remove unnecessary oom message
nilfs2: remove redundant continue statement in a while-loop
kprobes: remove duplicated strong free_insn_page in x86 and s390
init: print out unknown kernel parameters
checkpatch: do not complain about positive return values starting with EPOLL
checkpatch: improve the indented label test
checkpatch: scripts/spdxcheck.py now requires python3
...
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free_insn_page() in x86 and s390 is same with the common weak function in
kernel/kprobes.c. Plus, the comment "Recover page to RW mode before
releasing it" in x86 seems insensible to be there since resetting mapping
is done by common code in vfree() of module_memfree(). So drop these two
duplicated strong functions and related comment, then mark the common one
in kernel/kprobes.c strong.
Link: https://lkml.kernel.org/r/20210608065736.32656-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Kprobes has a counter 'nmissed', that is used to count the number of
times a probe handler was not called. This generally happens when we hit
a kprobe while handling another kprobe.
However, if one of the probe handlers causes a fault, we are currently
incrementing 'nmissed'. The comment in fault handler indicates that this
can be used to account faults taken by the probe handlers. But, this has
never been the intention as is evident from the comment above 'nmissed'
in 'struct kprobe':
/*count the number of times this probe was temporarily disarmed */
unsigned long nmissed;
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20210601120150.672652-1-naveen.n.rao@linux.vnet.ibm.com
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The reason for kprobe::fault_handler(), as given by their comment:
* We come here because instructions in the pre/post
* handler caused the page_fault, this could happen
* if handler tries to access user space by
* copy_from_user(), get_user() etc. Let the
* user-specified handler try to fix it first.
Is just plain bad. Those other handlers are ran from non-preemptible
context and had better use _nofault() functions. Also, there is no
upstream usage of this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:
- Remove address space overrides using set_fs()
- Convert to generic vDSO
- Convert to generic page table dumper
- Add ARCH_HAS_DEBUG_WX support
- Add leap seconds handling support
- Add NVMe firmware-assisted kernel dump support
- Extend NVMe boot support with memory clearing control and addition of
kernel parameters
- AP bus and zcrypt api code rework. Add adapter configure/deconfigure
interface. Extend debug features. Add failure injection support
- Add ECC secure private keys support
- Add KASan support for running protected virtualization host with
4-level paging
- Utilize destroy page ultravisor call to speed up secure guests
shutdown
- Implement ioremap_wc() and ioremap_prot() with MIO in PCI code
- Various checksum improvements
- Other small various fixes and improvements all over the code
* tag 's390-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (85 commits)
s390/uaccess: fix indentation
s390/uaccess: add default cases for __put_user_fn()/__get_user_fn()
s390/zcrypt: fix wrong format specifications
s390/kprobes: move insn_page to text segment
s390/sie: fix typo in SIGP code description
s390/lib: fix kernel doc for memcmp()
s390/zcrypt: Introduce Failure Injection feature
s390/zcrypt: move ap_msg param one level up the call chain
s390/ap/zcrypt: revisit ap and zcrypt error handling
s390/ap: Support AP card SCLP config and deconfig operations
s390/sclp: Add support for SCLP AP adapter config/deconfig
s390/ap: add card/queue deconfig state
s390/ap: add error response code field for ap queue devices
s390/ap: split ap queue state machine state from device state
s390/zcrypt: New config switch CONFIG_ZCRYPT_DEBUG
s390/zcrypt: introduce msg tracking in zcrypt functions
s390/startup: correct early pgm check info formatting
s390: remove orphaned extern variables declarations
s390/kasan: make sure int handler always run with DAT on
s390/ipl: add support to control memory clearing for nvme re-IPL
...
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Move the in-kernel kprobes insn page to text segment. Rationale:
having that page in rw data segment is suboptimal, since as soon as a
kprobe is set, this will split the 1:1 kernel mapping for a single
page which get new permissions.
Note: there is always at least one kprobe present for the kretprobe
trampoline; so the mapping will always be split into smaller 4k
mappings because of this.
Moving the kprobes insn page into text segment makes sure that the
page is mapped RO/X in any case, and avoids that the 1:1 mapping is
split.
The kprobe insn_page is defined as a dummy function which is filled
with "br %r14" instructions.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Make sure that kprobe insn pages are not writable anymore.
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Use the generic kretprobe trampoline handler. Don't use
framepointer verification.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/159870612453.1229682.15950927742606892302.stgit@devnote2
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This is a s390 port of commit 548acf19234d ("x86/mm: Expand the
exception table logic to allow new handling options"), which is needed
for implementing BPF_PROBE_MEM on s390.
The new handler field is made 64-bit in order to allow pointing from
dynamically allocated entries to handlers in kernel text. Unlike on x86,
NULL is used instead of ex_handler_default. This is because exception
tables are used by boot/text_dma.S, and it would be a pain to preserve
ex_handler_default.
The new infrastructure is ignored in early_pgm_check_handler, since
there is no pt_regs.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Instead of using our own kprobes-on-ftrace handling convert the
code to support KPROBES_ON_FTRACE.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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With a relocatable kernel that could reside at any place in memory, code
and data that has to stay below 2 GB needs special handling.
This patch introduces .dma sections for such text, data and ex_table.
The sections will be part of the decompressor kernel, so they will not
be relocated and stay below 2 GB. Their location is passed over to the
decompressed / relocated kernel via the .boot.preserved.data section.
The duald and aste for control register setup also need to stay below
2 GB, so move the setup code from arch/s390/kernel/head64.S to
arch/s390/boot/head.S. The duct and linkage_stack could reside above
2 GB, but their content has to be preserved for the decompresed kernel,
so they are also moved into the .dma section.
The start and end address of the .dma sections is added to vmcoreinfo,
for crash support, to help debugging in case the kernel crashed there.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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With a relocatable kernel that could reside at any place in memory, the
current logic for allocating a kprobes insn_page does not work. The
GFP_DMA allocated buffer might be more than 2 GB away from the kernel.
Use a static buffer for the insn_page instead.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Clear current_kprobe and enable preemption in kprobe
even if pre_handler returns !0.
This simplifies function override using kprobes.
Jprobe used to require to keep the preemption disabled and
keep current_kprobe until it returned to original function
entry. For this reason kprobe_int3_handler() and similar
arch dependent kprobe handers checks pre_handler result
and exit without enabling preemption if the result is !0.
After removing the jprobe, Kprobes does not need to
keep preempt disabled even if user handler returns !0
anymore.
But since the function override handler in error-inject
and bpf is also returns !0 if it overrides a function,
to balancing the preempt count, it enables preemption
and reset current kprobe by itself.
That is a bad design that is very buggy. This fixes
such unbalanced preempt-count and current_kprobes setting
in kprobes, bpf and error-inject.
Note: for powerpc and x86, this removes all preempt_disable
from kprobe_ftrace_handler because ftrace callbacks are
called under preempt disabled.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942494574.15209.12323837825873032258.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Don't call the ->break_handler() from the s390 kprobes code,
because it was only used by jprobes which got removed.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942485849.15209.16608277783809018031.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/s390.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942453967.15209.8535227381029256754.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Remove %p because the kprobe will be dumped in dump_kprobe().
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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These duplicate includes have been found with scripts/checkincludes.pl but
they have been removed manually to avoid removing false positives.
Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Now that the SPDX tag is in all arch/s390/kernel/ files, that identifies
the license in a specific and legally-defined manner. So the extra GPL
text wording can be removed as it is no longer needed at all.
This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.
No copyright headers or other non-license-description text was removed.
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.
Update the arch/s390/kernel/ files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.
This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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For an unknown reason the s390 kprobes instruction replacement
function modifies the kprobe_status of the current CPU to
KPROBE_SWAP_INST. This was supposed to catch traps that happened
during instruction patching. Such a fault is not supposed to happen,
and silently discarding such a fault is certainly also not what we
want. In fact s390 is the only architecture which has this odd piece
of code.
Just remove this and behave like all other architectures. This was
pointed out by Jens Remus.
Reported-by: Jens Remus <jremus@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The text patching functions which are invoked from jump_label and kprobes
code are protected against cpu hotplug at the call sites.
Use stop_machine_cpuslocked() to avoid recursion on the cpu hotplug
rwsem. stop_machine_cpuslocked() contains a lockdep assertion to catch any
unprotected callers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20170524081549.354513406@linutronix.de
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set_memory_* functions have moved to set_memory.h. Switch to this
explicitly
Link: http://lkml.kernel.org/r/1488920133-27229-5-git-send-email-labbott@redhat.com
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Bit 0x100 of a page table, segment table of region table entry
can be used to disallow code execution for the virtual addresses
associated with the entry.
There is one tricky bit, the system call to return from a signal
is part of the signal frame written to the user stack. With a
non-executable stack this would stop working. To avoid breaking
things the protection fault handler checks the opcode that caused
the fault for 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn)
and injects a system call. This is preferable to the alternative
solution with a stub function in the vdso because it works for
vdso=off and statically linked binaries as well.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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These files were only including module.h for exception table
related functions. We've now separated that content out into its
own file "extable.h" so now move over to that and avoid all the
extra header content in module.h that we don't really need to compile
these files.
The additions of uaccess.h are to deal with implict includes like:
arch/s390/kernel/traps.c: In function 'do_report_trap':
arch/s390/kernel/traps.c:56:4: error: implicit declaration of function 'extable_fixup' [-Werror=implicit-function-declaration]
arch/s390/kernel/traps.c: In function 'illegal_op':
arch/s390/kernel/traps.c:173:3: error: implicit declaration of function 'get_user' [-Werror=implicit-function-declaration]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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This fixes the same issue Steven already fixed for x86
in following commit:
237d28db036e ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing
It fixes the crash, that happens when function graph tracing
and jprobes are used simultaneously. Please refer to above
commit for details.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
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Yet another leftover from the 31 bit era. The usual operation
"y = x & PSW_ADDR_INSN" with the PSW_ADDR_INSN mask is a nop for
CONFIG_64BIT.
Therefore remove all usages and hope the code is a bit less confusing.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
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This is a leftover from the 31 bit area. For CONFIG_64BIT the usual
operation "y = x | PSW_ADDR_AMODE" is a nop. Therefore remove all
usages of PSW_ADDR_AMODE and make the code a bit less confusing.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
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Remove the s390 architecture implementation of probe_kernel_write() and
instead use a new function s390_kernel_write() to modify kernel text and
data everywhere.
The s390 implementation of probe_kernel_write() was potentially broken
since it modified memory in a read-modify-write fashion, which read four
bytes, modified the requested bytes within those four bytes and wrote
the result back.
If two cpus would modify the same four byte area at different locations
within that area, this could lead to corruption.
Right now the only places which called probe_kernel_write() did run within
stop_machine_run. Therefore the scenario can't happen right now, however
that might change at any time.
To fix this rename probe_kernel_write() to s390_kernel_write() which can
have special semantics, like only call it while running within stop_machine().
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Make use of gcc's hotpatch support to generate better code for ftrace
function tracing.
The generated code now contains only a six byte nop in each function
prologue instead of a 24 byte code block which will be runtime patched to
support function tracing.
With the new code generation the runtime overhead for supporting function
tracing is close to zero, while the original code did show a significant
performance impact.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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When we generate the instruction for out of line execution the length
of the to be copied instruction was evaluated from a not initialized
memory location.
Therefore we ended up with a random (2, 4 or 6) number of bytes being
copied instead of taking the real instruction length into account.
This works surprisingly well most of the time, but still not always.
Reported-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Use NOKPROBE_SYMBOL() instead of __kprobes annotation.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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