linux-dev/arch/s390/kernel/kprobes.c, branch linus/master

s390/kprobes: enable kretprobes framepointer verification

2022-03-27T20:18:39Z

Use regs->gprs[15] for framepointer verification. This enables additional sanity checks for nested kretprobes. Reviewed-by: Tobias Huschle Signed-off-by: Vasily Gorbik

s390/kprobes: Avoid additional kprobe in kretprobe handling

2022-03-10T14:58:17Z

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 Signed-off-by: Tobias Huschle Signed-off-by: Vasily Gorbik

s390/extable: add and use fixup_exception helper function

2022-03-07T23:33:00Z

Add and use fixup_exception helper function in order to remove the duplicated exception handler fixup code at several places. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2021-11-06T21:48:06Z

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 ...

s390/kprobes: add sanity check

2021-10-04T07:49:36Z

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 Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

kprobes: treewide: Make it harder to refer kretprobe_trampoline directly

2021-10-01T01:24:06Z

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 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()

2021-10-01T01:24:06Z

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 Tested-by: Andrii Nakryiko Signed-off-by: Steven Rostedt (VMware)

kprobes: treewide: Cleanup the error messages for kprobes

2021-10-01T01:24:05Z

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 Signed-off-by: Steven Rostedt (VMware)

s390/kprobes: use is_kernel() helper

2021-07-05T10:44:23Z

Use is_kernel() helper instead of is_kernel_addr(). [hca@linux.ibm.com: add missing unsigned long cast] Cc: Vasily Gorbik Cc: Christian Borntraeger Signed-off-by: Kefeng Wang Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

Merge branch 'akpm' (patches from Andrew)

2021-07-02T19:08:10Z

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 : (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 ...