user/sven/linux.git/arch/powerpc/kernel/ptrace, branch master

powerpc/ptrace: Convert gpr32_set_common_user() to scoped user access

2026-04-01T03:51:07Z

Commit 861574d51bbd ("powerpc/uaccess: Implement masked user access") provides optimised user access by avoiding the cost of access_ok(). Convert gpr32_set_common_user() to scoped user access to benefit from masked user access. Scoped user access also make the code simpler. Also changes label from Efault to efault to avoid checkpatch complaining about CamelCase. Signed-off-by: Christophe Leroy (CS GROUP) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/2409643daab08b4bc07004c2b88f42085d1ef45a.1773136838.git.chleroy@kernel.org

powerpc/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names

2025-07-15T05:27:48Z

Instead of having the core code guess the note name for each regset, use USER_REGSET_NOTE_TYPE() to pick the correct name from elf.h. Signed-off-by: Dave Martin Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Oleg Nesterov Cc: Kees Cook Cc: Akihiko Odaki Cc: linuxppc-dev@lists.ozlabs.org Reviewed-by: Akihiko Odaki Link: https://lore.kernel.org/r/20250701135616.29630-16-Dave.Martin@arm.com Signed-off-by: Kees Cook

seccomp: remove the 'sd' argument from __secure_computing()

2025-02-10T17:26:22Z

After the previous changes 'sd' is always NULL. Signed-off-by: Oleg Nesterov Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20250128150313.GA15336@redhat.com Signed-off-by: Kees Cook

powerpc: Fix typos

2024-05-07T14:21:30Z

Fix typos, most reported by "codespell arch/powerpc". Only touches comments, no code changes. Signed-off-by: Bjorn Helgaas Signed-off-by: Michael Ellerman Link: https://msgid.link/20240103231605.1801364-8-helgaas@kernel.org

powerpc/dexcr: Track the DEXCR per-process

2024-05-03T10:46:51Z

Add capability to make the DEXCR act as a per-process SPR. We do not yet have an interface for changing the values per task. We also expect the kernel to use a single DEXCR value across all tasks while in privileged state, so there is no need to synchronize after changing it (the userspace aspects will synchronize upon returning to userspace). Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20240417112325.728010-3-bgray@linux.ibm.com

powerpc: Replace GPL 2.0+ README.legal boilerplate with SPDX

2023-09-19T10:05:58Z

Upstream Linux never had a "README.legal" file, but it was present in early source releases of Linux/m68k. It contained a simple copyright notice and a link to a version of the "COPYING" file that predated the addition of the "only valid GPL version is v2" clause. Get rid of the references to non-existent files by replacing the boilerplate with SPDX license identifiers. Signed-off-by: Geert Uytterhoeven Acked-by: Michael Ellerman Signed-off-by: Michael Ellerman Link: https://msgid.link/d91725ff1ed5d4b6ba42474e2ebfeebe711cba23.1695031668.git.geert@linux-m68k.org

powerpc/ptrace: Split gpr32_set_common

2023-08-16T13:54:50Z

objtool reports the following warning: arch/powerpc/kernel/ptrace/ptrace-view.o: warning: objtool: gpr32_set_common+0x23c (.text+0x860): redundant UACCESS disable gpr32_set_common() conditionally opens and closes UACCESS based on whether kbuf pointer is NULL or not. This is wackelig. Split gpr32_set_common() in two fonctions, one for user one for kernel. Signed-off-by: Christophe Leroy [mpe: Fix oops in gpr32_set_common_user() due to NULL kbuf] Signed-off-by: Michael Ellerman Link: https://msgid.link/b8d6ae4483fcfd17524e79d803c969694a85cc02.1687428075.git.christophe.leroy@csgroup.eu

powerpc/ptrace: Expose HASHKEYR register to ptrace

2023-06-19T07:36:27Z

The HASHKEYR register contains a secret per-process key to enable unique hashes per process. In general it should not be exposed to userspace at all and a regular process has no need to know its key. However, checkpoint restore in userspace (CRIU) functionality requires that a process be able to set the HASHKEYR of another process, otherwise existing hashes on the stack would be invalidated by a new random key. Exposing HASHKEYR in this way also makes it appear in core dumps, which is a security concern. Multiple threads may share a key, for example just after a fork() call, where the kernel cannot know if the child is going to return back along the parent's stack. If such a thread is coerced into making a core dump, then the HASHKEYR value will be readable and able to be used against all other threads sharing that key, effectively undoing any protection offered by hashst/hashchk. Therefore we expose HASHKEYR to ptrace when CONFIG_CHECKPOINT_RESTORE is enabled, providing a choice of increased security or migratable ROP protected processes. This is similar to how ARM exposes its PAC keys. Signed-off-by: Benjamin Gray Reviewed-by: Russell Currey Signed-off-by: Michael Ellerman Link: https://msgid.link/20230616034846.311705-8-bgray@linux.ibm.com

powerpc/ptrace: Expose DEXCR and HDEXCR registers to ptrace

2023-06-19T07:36:26Z

The DEXCR register is of interest when ptracing processes. Currently it is static, but eventually will be dynamically controllable by a process. If a process can control its own, then it is useful for it to be ptrace-able to (e.g., for checkpoint-restore functionality). It is also relevant to core dumps (the NPHIE aspect in particular), which use the ptrace mechanism (or is it the other way around?) to decide what to dump. The HDEXCR is useful here too, as the NPHIE aspect may be set in the HDEXCR without being set in the DEXCR. Although the HDEXCR is per-cpu and we don't track it in the task struct (it's useless in normal operation), it would be difficult to imagine why a hypervisor would set it to different values within a guest. A hypervisor cannot safely set NPHIE differently at least, as that would break programs. Expose a read-only view of the userspace DEXCR and HDEXCR to ptrace. The HDEXCR is always readonly, and is useful for diagnosing the core dumps (as the HDEXCR may set NPHIE without the DEXCR setting it). Signed-off-by: Benjamin Gray Reviewed-by: Russell Currey [mpe: Use lower_32_bits() rather than open coding] Signed-off-by: Michael Ellerman Link: https://msgid.link/20230616034846.311705-7-bgray@linux.ibm.com

powerpc/ptrace: Add missing include

2023-06-19T07:36:25Z

ptrace-decl.h uses user_regset_get2_fn (among other things) from regset.h. While all current users of ptrace-decl.h include regset.h before it anyway, it adds an implicit ordering dependency and breaks source tooling that tries to inspect ptrace-decl.h by itself. Signed-off-by: Benjamin Gray Reviewed-by: Russell Currey Signed-off-by: Michael Ellerman Link: https://msgid.link/20230616034846.311705-3-bgray@linux.ibm.com