Re: [PATCH v2 2/8] powerpc: Prepare to build with generic entry/exit framework
From: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Date: 2025-12-16 09:28:08
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Le 14/12/2025 à 14:02, Mukesh Kumar Chaurasiya a écrit :
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From: Mukesh Kumar Chaurasiya <redacted> This patch introduces preparatory changes needed to support building PowerPC with the generic entry/exit (irqentry) framework. The following infrastructure updates are added: - Add a syscall_work field to struct thread_info to hold SYSCALL_WORK_* flags. - Provide a stub implementation of arch_syscall_is_vdso_sigreturn(), returning false for now. - Introduce on_thread_stack() helper to detect if the current stack pointer lies within the task’s kernel stack. These additions enable later integration with the generic entry/exit infrastructure while keeping existing PowerPC behavior unchanged. No functional change is intended in this patch. Signed-off-by: Mukesh Kumar Chaurasiya <redacted> --- arch/powerpc/include/asm/entry-common.h | 11 +++++++++++ arch/powerpc/include/asm/stacktrace.h | 6 ++++++ arch/powerpc/include/asm/syscall.h | 5 +++++ arch/powerpc/include/asm/thread_info.h | 1 + 4 files changed, 23 insertions(+) create mode 100644 arch/powerpc/include/asm/entry-common.hdiff --git a/arch/powerpc/include/asm/entry-common.h b/arch/powerpc/include/asm/entry-common.h new file mode 100644 index 000000000000..3af16d821d07 --- /dev/null +++ b/arch/powerpc/include/asm/entry-common.h@@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_PPC_ENTRY_COMMON_H +#define _ASM_PPC_ENTRY_COMMON_H + +#ifdef CONFIG_GENERIC_IRQ_ENTRY
Why do you need this #ifdef ? I see no reason, the build works well without this #ifdef. At the time being, CONFIG_GENERIC_IRQ_ENTRY is never selected by powerpc, meaning you are introducing dead code. If really needed it would be more explicit to add a "#if 0"
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+ +#include <asm/stacktrace.h> + +#endif /* CONFIG_GENERIC_IRQ_ENTRY */ +#endif /* _ASM_PPC_ENTRY_COMMON_H */diff --git a/arch/powerpc/include/asm/stacktrace.h b/arch/powerpc/include/asm/stacktrace.h index 6149b53b3bc8..a81a9373d723 100644 --- a/arch/powerpc/include/asm/stacktrace.h +++ b/arch/powerpc/include/asm/stacktrace.h@@ -10,4 +10,10 @@ void show_user_instructions(struct pt_regs *regs); +static inline bool on_thread_stack(void)
Shouldn't it be __always_inline ?
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+{ + return !(((unsigned long)(current->stack) ^ current_stack_pointer) + & ~(THREAD_SIZE - 1)); +} + #endif /* _ASM_POWERPC_STACKTRACE_H */diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h index 4b3c52ed6e9d..834fcc4f7b54 100644 --- a/arch/powerpc/include/asm/syscall.h +++ b/arch/powerpc/include/asm/syscall.h@@ -139,4 +139,9 @@ static inline int syscall_get_arch(struct task_struct *task) else return AUDIT_ARCH_PPC64; } + +static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs) +{ + return false; +} #endif /* _ASM_SYSCALL_H */diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index b0f200aba2b3..9c8270354f0b 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h@@ -57,6 +57,7 @@ struct thread_info { #ifdef CONFIG_SMP unsigned int cpu; #endif + unsigned long syscall_work; /* SYSCALL_WORK_ flags */
This is not used, why add it here ?
unsigned long local_flags; /* private flags for thread */ #ifdef CONFIG_LIVEPATCH_64 unsigned long *livepatch_sp;