linux-stable.git/arch/powerpc/kernel/ptrace, branch master Linux kernel stable tree powerpc: Remove unused functions 2026-05-20T01:27:14+00:00 Mukesh Kumar Chaurasiya mkchauras@linux.ibm.com 2026-04-27T12:27:42+00:00 6ed60999d33d49251b42976a5511f1bb089797ed After enabling GENERIC_ENTRY some functions are left unused. Cleanup all those functions which includes: - do_syscall_trace_enter - do_syscall_trace_leave - do_notify_resume - do_seccomp Signed-off-by: Mukesh Kumar Chaurasiya <mkchauras@linux.ibm.com> Tested-by: Samir M <samir@linux.ibm.com> Tested-by: David Gow <davidgow@google.com> Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20260427122742.210074-9-mkchauras@gmail.com 
After enabling GENERIC_ENTRY some functions are left unused.
Cleanup all those functions which includes:
 - do_syscall_trace_enter
 - do_syscall_trace_leave
 - do_notify_resume
 - do_seccomp

Signed-off-by: Mukesh Kumar Chaurasiya <mkchauras@linux.ibm.com>
Tested-by: Samir M <samir@linux.ibm.com>
Tested-by: David Gow <davidgow@google.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260427122742.210074-9-mkchauras@gmail.com
powerpc: Enable GENERIC_ENTRY feature 2026-05-20T01:27:14+00:00 Mukesh Kumar Chaurasiya mkchauras@linux.ibm.com 2026-04-27T12:27:41+00:00 bee25f97ad24641df55cb3887eb5bfcb2b9d8fbc Enable the generic IRQ entry/exit infrastructure on PowerPC by selecting GENERIC_ENTRY and integrating the architecture-specific interrupt and syscall handlers with the generic entry/exit APIs. This change replaces PowerPC’s local interrupt entry/exit handling with calls to the generic irqentry_* helpers, aligning the architecture with the common kernel entry model. The macros that define interrupt, async, and NMI handlers are updated to use irqentry_enter()/irqentry_exit() and irqentry_nmi_enter()/irqentry_nmi_exit() where applicable also convert the PowerPC syscall entry and exit paths to use the generic entry/exit framework and integrating with the common syscall handling routines. Key updates include: - The architecture now selects GENERIC_ENTRY in Kconfig. - Replace interrupt_enter/exit_prepare() with arch_interrupt_* helpers. - Integrate irqentry_enter()/exit() in standard and async interrupt paths. - Integrate irqentry_nmi_enter()/exit() in NMI handlers. - Remove redundant irq_enter()/irq_exit() calls now handled generically. - Use irqentry_exit_cond_resched() for preemption checks. - interrupt.c and syscall.c are simplified to delegate context management and user exit handling to the generic entry path. - The new pt_regs field `exit_flags` introduced earlier is now used to carry per-syscall exit state flags (e.g. _TIF_RESTOREALL). - Remove unused code. This change establishes the necessary wiring for PowerPC to use the generic IRQ entry/exit framework while maintaining existing semantics. This aligns PowerPC with the common entry code used by other architectures and reduces duplicated logic around syscall tracing, context tracking, and signal handling. The performance benchmarks from perf bench basic syscall are below: perf bench syscall usec/op (-ve is improvement) | Syscall | Base | test | change % | | ------- | ----------- | ----------- | -------- | | basic | 0.093543 | 0.093023 | -0.56 | | execve | 446.557781 | 450.107172 | +0.79 | | fork | 1142.204391 | 1156.377214 | +1.24 | | getpgid | 0.097666 | 0.092677 | -5.11 | perf bench syscall ops/sec (+ve is improvement) | Syscall | Base | New | change % | | ------- | -------- | -------- | -------- | | basic | 10690548 | 10750140 | +0.56 | | execve | 2239 | 2221 | -0.80 | | fork | 875 | 864 | -1.26 | | getpgid | 10239026 | 10790324 | +5.38 | IPI latency benchmark (-ve is improvement) | Metric | Base (ns) | New (ns) | % Change | | -------------- | ------------- | ------------- | -------- | | Dry run | 583136.56 | 584136.35 | 0.17% | | Self IPI | 4167393.42 | 4149093.90 | -0.44% | | Normal IPI | 61769347.82 | 61753728.39 | -0.03% | | Broadcast IPI | 2235584825.02 | 2227521401.45 | -0.36% | | Broadcast lock | 2164964433.31 | 2125658641.76 | -1.82% | Thats very close to performance earlier with arch specific handling. Signed-off-by: Mukesh Kumar Chaurasiya <mkchauras@linux.ibm.com> Tested-by: Samir M <samir@linux.ibm.com> Tested-by: David Gow <davidgow@google.com> Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20260427122742.210074-8-mkchauras@gmail.com 
Enable the generic IRQ entry/exit infrastructure on PowerPC by selecting
GENERIC_ENTRY and integrating the architecture-specific interrupt and
syscall handlers with the generic entry/exit APIs.

This change replaces PowerPC’s local interrupt entry/exit handling with
calls to the generic irqentry_* helpers, aligning the architecture with
the common kernel entry model. The macros that define interrupt, async,
and NMI handlers are updated to use irqentry_enter()/irqentry_exit()
and irqentry_nmi_enter()/irqentry_nmi_exit() where applicable also
convert the PowerPC syscall entry and exit paths to use the generic
entry/exit framework and integrating with the common syscall handling
routines.

Key updates include:
 - The architecture now selects GENERIC_ENTRY in Kconfig.
 - Replace interrupt_enter/exit_prepare() with arch_interrupt_* helpers.
 - Integrate irqentry_enter()/exit() in standard and async interrupt paths.
 - Integrate irqentry_nmi_enter()/exit() in NMI handlers.
 - Remove redundant irq_enter()/irq_exit() calls now handled generically.
 - Use irqentry_exit_cond_resched() for preemption checks.
 - interrupt.c and syscall.c are simplified to delegate context
   management and user exit handling to the generic entry path.
 - The new pt_regs field `exit_flags` introduced earlier is now used
   to carry per-syscall exit state flags (e.g. _TIF_RESTOREALL).
 - Remove unused code.

This change establishes the necessary wiring for PowerPC to use the
generic IRQ entry/exit framework while maintaining existing semantics.
This aligns PowerPC with the common entry code used by other
architectures and reduces duplicated logic around syscall tracing,
context tracking, and signal handling.

The performance benchmarks from perf bench basic syscall are below:

perf bench syscall usec/op (-ve is improvement)

| Syscall | Base        | test        | change % |
| ------- | ----------- | ----------- | -------- |
| basic   | 0.093543    | 0.093023    | -0.56    |
| execve  | 446.557781  | 450.107172  | +0.79    |
| fork    | 1142.204391 | 1156.377214 | +1.24    |
| getpgid | 0.097666    | 0.092677    | -5.11    |

perf bench syscall ops/sec (+ve is improvement)

| Syscall | Base     | New      | change % |
| ------- | -------- | -------- | -------- |
| basic   | 10690548 | 10750140 | +0.56    |
| execve  | 2239     | 2221     | -0.80    |
| fork    | 875      | 864      | -1.26    |
| getpgid | 10239026 | 10790324 | +5.38    |

IPI latency benchmark (-ve is improvement)

| Metric         | Base (ns)     | New (ns)      | % Change |
| -------------- | ------------- | ------------- | -------- |
| Dry run        | 583136.56     | 584136.35     | 0.17%    |
| Self IPI       | 4167393.42    | 4149093.90    | -0.44%   |
| Normal IPI     | 61769347.82   | 61753728.39   | -0.03%   |
| Broadcast IPI  | 2235584825.02 | 2227521401.45 | -0.36%   |
| Broadcast lock | 2164964433.31 | 2125658641.76 | -1.82%   |

Thats very close to performance earlier with arch specific handling.

Signed-off-by: Mukesh Kumar Chaurasiya <mkchauras@linux.ibm.com>
Tested-by: Samir M <samir@linux.ibm.com>
Tested-by: David Gow <davidgow@google.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260427122742.210074-8-mkchauras@gmail.com
powerpc: add exit_flags field in pt_regs 2026-05-20T01:27:14+00:00 Mukesh Kumar Chaurasiya mchauras@linux.ibm.com 2026-04-27T12:27:39+00:00 d7a6797e0bc1ee7bddb8a298f2d1acddb300efb3 Add a new field `exit_flags` in the pt_regs structure. This field will hold the flags set during interrupt or syscall execution that are required during exit to user mode. Specifically, the `TIF_RESTOREALL` flag, stored in this field, helps the exit routine determine if any NVGPRs were modified and need to be restored before returning to userspace. This addition ensures a clean and architecture-specific mechanism to track per-syscall or per-interrupt state transitions related to register restore. Changes: - Add `exit_flags` and `__pt_regs_pad` to maintain 16-byte stack alignment - Update asm-offsets.c and ptrace.c for offset and validation - Update PT_* constants in uapi header to reflect the new layout Signed-off-by: Mukesh Kumar Chaurasiya <mchauras@linux.ibm.com> Tested-by: Samir M <samir@linux.ibm.com> Tested-by: David Gow <davidgow@google.com> Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20260427122742.210074-6-mkchauras@gmail.com 
Add a new field `exit_flags` in the pt_regs structure. This field will hold
the flags set during interrupt or syscall execution that are required during
exit to user mode.

Specifically, the `TIF_RESTOREALL` flag, stored in this field, helps the
exit routine determine if any NVGPRs were modified and need to be restored
before returning to userspace.

This addition ensures a clean and architecture-specific mechanism to track
per-syscall or per-interrupt state transitions related to register restore.

Changes:
 - Add `exit_flags` and `__pt_regs_pad` to maintain 16-byte stack alignment
 - Update asm-offsets.c and ptrace.c for offset and validation
 - Update PT_* constants in uapi header to reflect the new layout

Signed-off-by: Mukesh Kumar Chaurasiya <mchauras@linux.ibm.com>
Tested-by: Samir M <samir@linux.ibm.com>
Tested-by: David Gow <davidgow@google.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260427122742.210074-6-mkchauras@gmail.com
powerpc/ptrace: Convert gpr32_set_common_user() to scoped user access 2026-04-01T03:51:07+00:00 Christophe Leroy (CS GROUP) chleroy@kernel.org 2026-03-10T10:00:53+00:00 679fa9c756c7d6fcb6ae611f695d286c53dca076 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) <chleroy@kernel.org> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/2409643daab08b4bc07004c2b88f42085d1ef45a.1773136838.git.chleroy@kernel.org 
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) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/2409643daab08b4bc07004c2b88f42085d1ef45a.1773136838.git.chleroy@kernel.org
powerpc/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names 2025-07-15T05:27:48+00:00 Dave Martin Dave.Martin@arm.com 2025-07-01T13:56:08+00:00 307035acefbd6ce31e6f7086c064a645a39ba980 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 <Dave.Martin@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <kees@kernel.org> Cc: Akihiko Odaki <akihiko.odaki@daynix.com> Cc: linuxppc-dev@lists.ozlabs.org Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Link: https://lore.kernel.org/r/20250701135616.29630-16-Dave.Martin@arm.com Signed-off-by: Kees Cook <kees@kernel.org> 
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 <Dave.Martin@arm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Link: https://lore.kernel.org/r/20250701135616.29630-16-Dave.Martin@arm.com
Signed-off-by: Kees Cook <kees@kernel.org>
seccomp: remove the 'sd' argument from __secure_computing() 2025-02-10T17:26:22+00:00 Oleg Nesterov oleg@redhat.com 2025-01-28T15:03:13+00:00 1027cd8084bbcdf80d8a096d5e2c6da91402fc3c After the previous changes 'sd' is always NULL. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250128150313.GA15336@redhat.com Signed-off-by: Kees Cook <kees@kernel.org> 
After the previous changes 'sd' is always NULL.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250128150313.GA15336@redhat.com
Signed-off-by: Kees Cook <kees@kernel.org>
powerpc: Fix typos 2024-05-07T14:21:30+00:00 Bjorn Helgaas bhelgaas@google.com 2024-01-03T23:16:04+00:00 0ddbbb8960eaf91c7b432ec80566dfa60a8d79e4 Fix typos, most reported by "codespell arch/powerpc". Only touches comments, no code changes. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240103231605.1801364-8-helgaas@kernel.org 
Fix typos, most reported by "codespell arch/powerpc".  Only touches
comments, no code changes.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240103231605.1801364-8-helgaas@kernel.org
powerpc/dexcr: Track the DEXCR per-process 2024-05-03T10:46:51+00:00 Benjamin Gray bgray@linux.ibm.com 2024-04-17T11:23:18+00:00 75171f06c4507c3b6b5a69d793879fb20d108bb1 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 <bgray@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240417112325.728010-3-bgray@linux.ibm.com 
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 <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-3-bgray@linux.ibm.com
powerpc: Replace GPL 2.0+ README.legal boilerplate with SPDX 2023-09-19T10:05:58+00:00 Geert Uytterhoeven geert@linux-m68k.org 2023-09-18T10:14:44+00:00 6fcb13972bc2b41211e1dddb02f5e73199addc75 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 <geert@linux-m68k.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/d91725ff1ed5d4b6ba42474e2ebfeebe711cba23.1695031668.git.geert@linux-m68k.org 
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 <geert@linux-m68k.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/d91725ff1ed5d4b6ba42474e2ebfeebe711cba23.1695031668.git.geert@linux-m68k.org
powerpc/ptrace: Split gpr32_set_common 2023-08-16T13:54:50+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2023-06-22T10:01:23+00:00 9a32584bc108c8fe4d02fa33b16caf686e4a788a 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 <christophe.leroy@csgroup.eu> [mpe: Fix oops in gpr32_set_common_user() due to NULL kbuf] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/b8d6ae4483fcfd17524e79d803c969694a85cc02.1687428075.git.christophe.leroy@csgroup.eu 
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 <christophe.leroy@csgroup.eu>
[mpe: Fix oops in gpr32_set_common_user() due to NULL kbuf]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/b8d6ae4483fcfd17524e79d803c969694a85cc02.1687428075.git.christophe.leroy@csgroup.eu