kernel/linux.git/arch/powerpc/include/asm/syscall.h, branch v6.18.22

syscall.h: introduce syscall_set_nr()

2025-05-12T00:48:15+00:00

Similar to syscall_set_arguments() that complements syscall_get_arguments(), introduce syscall_set_nr() that complements syscall_get_nr(). syscall_set_nr() is going to be needed along with syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK architectures to implement PTRACE_SET_SYSCALL_INFO API. Link: https://lkml.kernel.org/r/20250303112020.GD24170@strace.io Signed-off-by: Dmitry V. Levin Tested-by: Charlie Jenkins Reviewed-by: Charlie Jenkins Acked-by: Helge Deller # parisc Reviewed-by: Maciej W. Rozycki # mips Cc: Alexander Gordeev Cc: Alexey Gladkov (Intel) Cc: Andreas Larsson Cc: anton ivanov Cc: Arnd Bergmann Cc: Borislav Betkov Cc: Brian Cain Cc: Christian Borntraeger Cc: Christian Zankel Cc: Christophe Leroy Cc: Dave Hansen Cc: Davide Berardi Cc: David S. Miller Cc: Dinh Nguyen Cc: Eugene Syromiatnikov Cc: Eugene Syromyatnikov Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Jonas Bonn Cc: Madhavan Srinivasan Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Frysinger Cc: Naveen N Rao Cc: Nicholas Piggin Cc: Oleg Nesterov Cc: Renzo Davoi Cc: Richard Weinberger Cc: Rich Felker Cc: Russel King Cc: Shuah Khan Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Sven Schnelle Cc: Thomas Gleinxer Cc: Vasily Gorbik Cc: Vineet Gupta Cc: WANG Xuerui Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton

syscall.h: add syscall_set_arguments()

2025-05-12T00:48:15+00:00

This function is going to be needed on all HAVE_ARCH_TRACEHOOK architectures to implement PTRACE_SET_SYSCALL_INFO API. This partially reverts commit 7962c2eddbfe ("arch: remove unused function syscall_set_arguments()") by reusing some of old syscall_set_arguments() implementations. [nathan@kernel.org: fix compile time fortify checks] Link: https://lkml.kernel.org/r/20250408213131.GA2872426@ax162 Link: https://lkml.kernel.org/r/20250303112009.GC24170@strace.io Signed-off-by: Dmitry V. Levin Signed-off-by: Nathan Chancellor Tested-by: Charlie Jenkins Reviewed-by: Charlie Jenkins Acked-by: Helge Deller # parisc Reviewed-by: Maciej W. Rozycki [mips] Cc: Alexander Gordeev Cc: Alexey Gladkov (Intel) Cc: Andreas Larsson Cc: anton ivanov Cc: Arnd Bergmann Cc: Borislav Betkov Cc: Brian Cain Cc: Christian Borntraeger Cc: Christian Zankel Cc: Christophe Leroy Cc: Dave Hansen Cc: Davide Berardi Cc: David S. Miller Cc: Dinh Nguyen Cc: Eugene Syromiatnikov Cc: Eugene Syromyatnikov Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Jonas Bonn Cc: Madhavan Srinivasan Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Frysinger Cc: Naveen N Rao Cc: Nicholas Piggin Cc: Oleg Nesterov Cc: Renzo Davoi Cc: Richard Weinberger Cc: Rich Felker Cc: Russel King Cc: Shuah Khan Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Sven Schnelle Cc: Thomas Gleinxer Cc: Vasily Gorbik Cc: Vineet Gupta Cc: WANG Xuerui Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton

powerpc: Provide syscall wrapper

2022-09-28T09:22:09+00:00

Implement syscall wrapper as per s390, x86, arm64. When enabled cause handlers to accept parameters from a stack frame rather than from user scratch register state. This allows for user registers to be safely cleared in order to reduce caller influence on speculation within syscall routine. The wrapper is a macro that emits syscall handler symbols that call into the target handler, obtaining its parameters from a struct pt_regs on the stack. As registers are already saved to the stack prior to calling system_call_exception, it appears that this function is executed more efficiently with the new stack-pointer convention than with parameters passed by registers, avoiding the allocation of a stack frame for this method. On a 32-bit system, we see >20% performance increases on the null_syscall microbenchmark, and on a Power 8 the performance gains amortise the cost of clearing and restoring registers which is implemented at the end of this series, seeing final result of ~5.6% performance improvement on null_syscall. Syscalls are wrapped in this fashion on all platforms except for the Cell processor as this commit does not provide SPU support. This can be quickly fixed in a successive patch, but requires spu_sys_callback to allocate a pt_regs structure to satisfy the wrapped calling convention. Co-developed-by: Andrew Donnellan Signed-off-by: Andrew Donnellan Signed-off-by: Rohan McLure Reviewed-by: Nicholas Piggin [mpe: Make incompatible with COMPAT to retain clearing of high bits of args] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220921065605.1051927-22-rmclure@linux.ibm.com

powerpc: Use common syscall handler type

2022-09-28T09:22:09+00:00

Cause syscall handlers to be typed as follows when called indirectly throughout the kernel. This is to allow for better type checking. typedef long (*syscall_fn)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); Since both 32 and 64-bit abis allow for at least the first six machine-word length parameters to a function to be passed by registers, even handlers which admit fewer than six parameters may be viewed as having the above type. Coercing syscalls to syscall_fn requires a cast to void* to avoid -Wcast-function-type. Fixup comparisons in VDSO to avoid pointer-integer comparison. Introduce explicit cast on systems with SPUs. Signed-off-by: Rohan McLure Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220921065605.1051927-19-rmclure@linux.ibm.com

powerpc/audit: Fix syscall_get_arch()

2022-01-15T01:21:26+00:00

Commit 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()") and commit 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()") replaced test_tsk_thread_flag(task, TIF_32BIT)) by is_32bit_task(). But is_32bit_task() applies on current task while be want the test done on task 'task' So add a new macro is_tsk_32bit_task() to check any task. Fixes: 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()") Fixes: 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()") Cc: stable@vger.kernel.org Reported-by: Dmitry V. Levin Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c55cddb8f65713bf5859ed675d75a50cb37d5995.1642159570.git.christophe.leroy@csgroup.eu

arch: remove unused function syscall_set_arguments()

2021-09-14T14:06:20+00:00

This function appears to have been unused since it was first introduced in commit 828c365cc8b8 ("tracehook: asm/syscall.h"). Signed-off-by: Peter Collingbourne Link: https://linux-review.googlesource.com/id/I8ce04f002903a37c0b6c1d16e9b2a3afa716c097 Signed-off-by: Arnd Bergmann

powerpc/audit: Simplify syscall_get_arch()

2021-08-20T12:38:13+00:00

Make use of is_32bit_task() and CONFIG_CPU_LITTLE_ENDIAN to simplify syscall_get_arch(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4be53b9187a4d8c163968f4d224267e41a7fcc33.1629451479.git.christophe.leroy@csgroup.eu

powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()

2021-08-20T12:38:08+00:00

Use is_32bit_task() which already handles CONFIG_COMPAT. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ba49cdd574558a0363300c3f6b5b062b397cb071.1629451483.git.christophe.leroy@csgroup.eu

powerpc/64s/syscall: Fix ptrace syscall info with scv syscalls

2021-05-20T14:58:56+00:00

The scv implementation missed updating syscall return value and error value get/set functions to deal with the changed register ABI. This broke ptrace PTRACE_GET_SYSCALL_INFO as well as some kernel auditing and tracing functions. Fix. tools/testing/selftests/ptrace/get_syscall_info now passes when scv is used. Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Cc: stable@vger.kernel.org # v5.9+ Reported-by: "Dmitry V. Levin" Signed-off-by: Nicholas Piggin Reviewed-by: Dmitry V. Levin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210520111931.2597127-2-npiggin@gmail.com

powerpc: trap_is_syscall() helper to hide syscall trap number

2020-05-15T01:58:54+00:00

A new system call interrupt will be added with a new trap number. Hide the explicit 0xc00 test behind an accessor to reduce churn in callers. Signed-off-by: Nicholas Piggin [mpe: Make it a static inline] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200507121332.2233629-3-mpe@ellerman.id.au