[PATCH v14 0/4] arm64: Use generic TIF bits for common thread flags

[PATCH v14 0/4] arm64: Use generic TIF bits for common thread flags

[Jinjie Ruan]

This series use generic TIF bits for common thread flags and add
Syscall User Dispatch (SUD) testcase support for AArch64. So we can
enables RSEQ optimizations for arm64.

These patches follow the foundational series (v13 resend 1-10, "arm64:
entry: Convert to Generic Entry") and are intended for the next cycle or
an immutable branch based on v7.0-rc1.

Changes in v14:
- Split into two patch sets as Linus Walleij suggested, this is the second
  patch set.
- Remove TIF_FREEZE for arm64.
- Add Signed-off-by and test results for sud_benchmark.
- Collect Reviewed-by and Acked-by.
- Link to v13 resend: https://lore.kernel.org/all/20260317082020.737779-15-ruanjinjie@huawei.com/

Changes in v13 resend:
- Fix exit_to_user_mode_prepare_legacy() issues.
- Also move TIF_SINGLESTEP to generic TIF infrastructure for loongarch.
- Use generic TIF bits for arm64 and moving TIF_SINGLESTEP to
  generic TIF for related architectures separately.
- Refactor syscall_trace_enter/exit() to accept flags and Use
  syscall_get_nr() helper separately.
- Tested with slice_test for rseq optimizations.
- Add acked-by.
- Link to v13: https://lore.kernel.org/all/20260313094738.3985794-1-ruanjinjie@huawei.com/

Changes in v13:
- Rebased on v7.0-rc3, so drop the firt applied arm64 patch.
- Use generic TIF bits to enables RSEQ optimization.
- Update most of the commit message to make it more clear.
- Link to v12: https://lore.kernel.org/all/20260203133728.848283-1-ruanjinjie@huawei.com/

Changes in v12:
- Rebased on "sched/core", so remove the four generic entry patches.
- Move "Expand secure_computing() in place" and
  "Use syscall_get_arguments() helper" patch forward, which will group all
  non-functional cleanups at the front.
- Adjust the explanation for moving rseq_syscall() before
  audit_syscall_exit().
- Link to v11: https://lore.kernel.org/all/20260128031934.3906955-1-ruanjinjie@huawei.com/

Changes in v11:
- Remove unused syscall in syscall_trace_enter().
- Update and provide a detailed explanation of the differences after
  moving rseq_syscall() before audit_syscall_exit().
- Rebased on arm64 (for-next/entry), and remove the first applied 3 patchs.
- syscall_exit_to_user_mode_work() for arch reuse instead of adding
  new syscall_exit_to_user_mode_work_prepare() helper.
- Link to v10: https://lore.kernel.org/all/20251222114737.1334364-1-ruanjinjie@huawei.com/

Changes in v10:
- Rebased on v6.19-rc1, rename syscall_exit_to_user_mode_prepare() to
  syscall_exit_to_user_mode_work_prepare() to avoid conflict.
- Also inline syscall_trace_enter().
- Support aarch64 for sud_benchmark.
- Update and correct the commit message.
- Add Reviewed-by.
- Link to v9: https://lore.kernel.org/all/20251204082123.2792067-1-ruanjinjie@huawei.com/

Changes in v9:
- Move "Return early for ptrace_report_syscall_entry() error" patch ahead
  to make it not introduce a regression.
- Not check _TIF_SECCOMP/SYSCALL_EMU for syscall_exit_work() in
  a separate patch.
- Do not report_syscall_exit() for PTRACE_SYSEMU_SINGLESTEP in a separate
  patch.
- Add two performance patch to improve the arm64 performance.
- Add Reviewed-by.
- Link to v8: https://lore.kernel.org/all/20251126071446.3234218-1-ruanjinjie@huawei.com/

Changes in v8:
- Rename "report_syscall_enter()" to "report_syscall_entry()".
- Add ptrace_save_reg() to avoid duplication.
- Remove unused _TIF_WORK_MASK in a standalone patch.
- Align syscall_trace_enter() return value with the generic version.
- Use "scno" instead of regs->syscallno in el0_svc_common().
- Move rseq_syscall() ahead in a standalone patch to clarify it clearly.
- Rename "syscall_trace_exit()" to "syscall_exit_work()".
- Keep the goto in el0_svc_common().
- No argument was passed to __secure_computing() and check -1 not -1L.
- Remove "Add has_syscall_work() helper" patch.
- Move "Add syscall_exit_to_user_mode_prepare() helper" patch later.
- Add miss header for asm/entry-common.h.
- Update the implementation of arch_syscall_is_vdso_sigreturn().
- Add "ARCH_SYSCALL_WORK_EXIT" to be defined as "SECCOMP | SYSCALL_EMU"
  to keep the behaviour unchanged.
- Add more testcases test.
- Add Reviewed-by.
- Update the commit message.
- Link to v7: https://lore.kernel.org/all/20251117133048.53182-1-ruanjinjie@huawei.com/

Jinjie Ruan (3):
  s390: Rename TIF_SINGLE_STEP to TIF_SINGLESTEP
  asm-generic: Move TIF_SINGLESTEP to generic TIF bits
  arm64: Use generic TIF bits for common thread flags

kemal (1):
  selftests: sud_test: Support aarch64

 arch/arm64/Kconfig                            |  1 +
 arch/arm64/include/asm/thread_info.h          | 61 ++++++++-----------
 arch/loongarch/include/asm/thread_info.h      | 11 ++--
 arch/s390/include/asm/thread_info.h           |  7 +--
 arch/s390/kernel/process.c                    |  2 +-
 arch/s390/kernel/ptrace.c                     | 20 +++---
 arch/s390/kernel/signal.c                     |  6 +-
 arch/x86/include/asm/thread_info.h            |  6 +-
 include/asm-generic/thread_info_tif.h         |  5 ++
 .../syscall_user_dispatch/sud_benchmark.c     |  2 +-
 .../syscall_user_dispatch/sud_test.c          |  4 ++
 11 files changed, 61 insertions(+), 64 deletions(-)

-- 
2.34.1

[PATCH v14 1/4] s390: Rename TIF_SINGLE_STEP to TIF_SINGLESTEP

[Jinjie Ruan]

Rename TIF_SINGLE_STEP to TIF_SINGLESTEP to align with the naming
convention used by arm64, x86, and other architectures.

By aligning the name, TIF_SINGLESTEP can be consolidated into the generic
TIF bits definitions, reducing architectural divergence and simplifying
cross-architecture entry/exit logic.

No functional changes intended.

Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/s390/include/asm/thread_info.h |  4 ++--
 arch/s390/kernel/process.c          |  2 +-
 arch/s390/kernel/ptrace.c           | 20 ++++++++++----------
 arch/s390/kernel/signal.c           |  6 +++---
 4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 6a548a819400..1bcd42614e41 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -69,7 +69,7 @@ void arch_setup_new_exec(void);
 #define TIF_GUARDED_STORAGE	17	/* load guarded storage control block */
 #define TIF_ISOLATE_BP_GUEST	18	/* Run KVM guests with isolated BP */
 #define TIF_PER_TRAP		19	/* Need to handle PER trap on exit to usermode */
-#define TIF_SINGLE_STEP		21	/* This task is single stepped */
+#define TIF_SINGLESTEP		21	/* This task is single stepped */
 #define TIF_BLOCK_STEP		22	/* This task is block stepped */
 #define TIF_UPROBE_SINGLESTEP	23	/* This task is uprobe single stepped */
 
@@ -77,7 +77,7 @@ void arch_setup_new_exec(void);
 #define _TIF_GUARDED_STORAGE	BIT(TIF_GUARDED_STORAGE)
 #define _TIF_ISOLATE_BP_GUEST	BIT(TIF_ISOLATE_BP_GUEST)
 #define _TIF_PER_TRAP		BIT(TIF_PER_TRAP)
-#define _TIF_SINGLE_STEP	BIT(TIF_SINGLE_STEP)
+#define _TIF_SINGLESTEP	BIT(TIF_SINGLESTEP)
 #define _TIF_BLOCK_STEP		BIT(TIF_BLOCK_STEP)
 #define _TIF_UPROBE_SINGLESTEP	BIT(TIF_UPROBE_SINGLESTEP)
 
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 0df95dcb2101..3accc0c064a0 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -122,7 +122,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	/* Don't copy debug registers */
 	memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
 	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
-	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
+	clear_tsk_thread_flag(p, TIF_SINGLESTEP);
 	p->thread.per_flags = 0;
 	/* Initialize per thread user and system timer values */
 	p->thread.user_timer = 0;
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 125ca4c4e30c..d2cf91f4ac3f 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -90,8 +90,8 @@ void update_cr_regs(struct task_struct *task)
 	new.start.val = thread->per_user.start;
 	new.end.val = thread->per_user.end;
 
-	/* merge TIF_SINGLE_STEP into user specified PER registers. */
-	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
+	/* merge TIF_SINGLESTEP into user specified PER registers. */
+	if (test_tsk_thread_flag(task, TIF_SINGLESTEP) ||
 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
 			new.control.val |= PER_EVENT_BRANCH;
@@ -119,18 +119,18 @@ void update_cr_regs(struct task_struct *task)
 void user_enable_single_step(struct task_struct *task)
 {
 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
-	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
+	set_tsk_thread_flag(task, TIF_SINGLESTEP);
 }
 
 void user_disable_single_step(struct task_struct *task)
 {
 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
-	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
+	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 }
 
 void user_enable_block_step(struct task_struct *task)
 {
-	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
+	set_tsk_thread_flag(task, TIF_SINGLESTEP);
 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 }
 
@@ -143,7 +143,7 @@ void ptrace_disable(struct task_struct *task)
 {
 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
-	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
+	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 	clear_tsk_thread_flag(task, TIF_PER_TRAP);
 	task->thread.per_flags = 0;
 }
@@ -155,19 +155,19 @@ static inline unsigned long __peek_user_per(struct task_struct *child,
 {
 	if (addr == offsetof(struct per_struct_kernel, cr9))
 		/* Control bits of the active per set. */
-		return test_thread_flag(TIF_SINGLE_STEP) ?
+		return test_thread_flag(TIF_SINGLESTEP) ?
 			PER_EVENT_IFETCH : child->thread.per_user.control;
 	else if (addr == offsetof(struct per_struct_kernel, cr10))
 		/* Start address of the active per set. */
-		return test_thread_flag(TIF_SINGLE_STEP) ?
+		return test_thread_flag(TIF_SINGLESTEP) ?
 			0 : child->thread.per_user.start;
 	else if (addr == offsetof(struct per_struct_kernel, cr11))
 		/* End address of the active per set. */
-		return test_thread_flag(TIF_SINGLE_STEP) ?
+		return test_thread_flag(TIF_SINGLESTEP) ?
 			-1UL : child->thread.per_user.end;
 	else if (addr == offsetof(struct per_struct_kernel, bits))
 		/* Single-step bit. */
-		return test_thread_flag(TIF_SINGLE_STEP) ?
+		return test_thread_flag(TIF_SINGLESTEP) ?
 			(1UL << (BITS_PER_LONG - 1)) : 0;
 	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 		/* Start address of the user specified per set. */
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 4874de5edea0..83f7650f2032 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -423,7 +423,7 @@ static void handle_signal(struct ksignal *ksig, sigset_t *oldset,
 	else
 		ret = setup_frame(ksig->sig, &ksig->ka, oldset, regs);
 
-	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
+	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
 }
 
 /*
@@ -491,7 +491,7 @@ void arch_do_signal_or_restart(struct pt_regs *regs)
 			regs->gprs[2] = regs->orig_gpr2;
 			current->restart_block.arch_data = regs->psw.addr;
 			regs->psw.addr = VDSO_SYMBOL(current, restart_syscall);
-			if (test_thread_flag(TIF_SINGLE_STEP))
+			if (test_thread_flag(TIF_SINGLESTEP))
 				clear_thread_flag(TIF_PER_TRAP);
 			break;
 		case -ERESTARTNOHAND:
@@ -499,7 +499,7 @@ void arch_do_signal_or_restart(struct pt_regs *regs)
 		case -ERESTARTNOINTR:
 			regs->gprs[2] = regs->orig_gpr2;
 			regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
-			if (test_thread_flag(TIF_SINGLE_STEP))
+			if (test_thread_flag(TIF_SINGLESTEP))
 				clear_thread_flag(TIF_PER_TRAP);
 			break;
 		}
-- 
2.34.1

[PATCH v14 2/4] asm-generic: Move TIF_SINGLESTEP to generic TIF bits

[Jinjie Ruan]

Currently, x86, ARM64, s390, and LoongArch all define and use
TIF_SINGLESTEP to track single-stepping state.

Since this flag is shared across multiple major architectures and serves
a common purpose in the generic entry/exit paths, move TIF_SINGLESTEP
into the generic Thread Information Flags (TIF) infrastructure.

This consolidation reduces architecture-specific boilerplate code and
ensures consistency for generic features that rely on single-step
state tracking.

Cc: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/loongarch/include/asm/thread_info.h | 11 +++++------
 arch/s390/include/asm/thread_info.h      |  7 +++----
 arch/x86/include/asm/thread_info.h       |  6 ++----
 include/asm-generic/thread_info_tif.h    |  5 +++++
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/loongarch/include/asm/thread_info.h b/arch/loongarch/include/asm/thread_info.h
index 4d7117fcdc78..a2ec87f18e1d 100644
--- a/arch/loongarch/include/asm/thread_info.h
+++ b/arch/loongarch/include/asm/thread_info.h
@@ -70,6 +70,7 @@ register unsigned long current_stack_pointer __asm__("$sp");
  */
 #define HAVE_TIF_NEED_RESCHED_LAZY
 #define HAVE_TIF_RESTORE_SIGMASK
+#define HAVE_TIF_SINGLESTEP
 
 #include <asm-generic/thread_info_tif.h>
 
@@ -82,11 +83,10 @@ register unsigned long current_stack_pointer __asm__("$sp");
 #define TIF_32BIT_REGS		21	/* 32-bit general purpose registers */
 #define TIF_32BIT_ADDR		22	/* 32-bit address space */
 #define TIF_LOAD_WATCH		23	/* If set, load watch registers */
-#define TIF_SINGLESTEP		24	/* Single Step */
-#define TIF_LSX_CTX_LIVE	25	/* LSX context must be preserved */
-#define TIF_LASX_CTX_LIVE	26	/* LASX context must be preserved */
-#define TIF_USEDLBT		27	/* LBT was used by this task this quantum (SMP) */
-#define TIF_LBT_CTX_LIVE	28	/* LBT context must be preserved */
+#define TIF_LSX_CTX_LIVE	24	/* LSX context must be preserved */
+#define TIF_LASX_CTX_LIVE	25	/* LASX context must be preserved */
+#define TIF_USEDLBT		26	/* LBT was used by this task this quantum (SMP) */
+#define TIF_LBT_CTX_LIVE	27	/* LBT context must be preserved */
 
 #define _TIF_NOHZ		BIT(TIF_NOHZ)
 #define _TIF_USEDFPU		BIT(TIF_USEDFPU)
@@ -96,7 +96,6 @@ register unsigned long current_stack_pointer __asm__("$sp");
 #define _TIF_32BIT_REGS		BIT(TIF_32BIT_REGS)
 #define _TIF_32BIT_ADDR		BIT(TIF_32BIT_ADDR)
 #define _TIF_LOAD_WATCH		BIT(TIF_LOAD_WATCH)
-#define _TIF_SINGLESTEP		BIT(TIF_SINGLESTEP)
 #define _TIF_LSX_CTX_LIVE	BIT(TIF_LSX_CTX_LIVE)
 #define _TIF_LASX_CTX_LIVE	BIT(TIF_LASX_CTX_LIVE)
 #define _TIF_USEDLBT		BIT(TIF_USEDLBT)
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 1bcd42614e41..95be5258a422 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -61,6 +61,7 @@ void arch_setup_new_exec(void);
  */
 #define HAVE_TIF_NEED_RESCHED_LAZY
 #define HAVE_TIF_RESTORE_SIGMASK
+#define HAVE_TIF_SINGLESTEP
 
 #include <asm-generic/thread_info_tif.h>
 
@@ -69,15 +70,13 @@ void arch_setup_new_exec(void);
 #define TIF_GUARDED_STORAGE	17	/* load guarded storage control block */
 #define TIF_ISOLATE_BP_GUEST	18	/* Run KVM guests with isolated BP */
 #define TIF_PER_TRAP		19	/* Need to handle PER trap on exit to usermode */
-#define TIF_SINGLESTEP		21	/* This task is single stepped */
-#define TIF_BLOCK_STEP		22	/* This task is block stepped */
-#define TIF_UPROBE_SINGLESTEP	23	/* This task is uprobe single stepped */
+#define TIF_BLOCK_STEP		20	/* This task is block stepped */
+#define TIF_UPROBE_SINGLESTEP	21	/* This task is uprobe single stepped */
 
 #define _TIF_ASCE_PRIMARY	BIT(TIF_ASCE_PRIMARY)
 #define _TIF_GUARDED_STORAGE	BIT(TIF_GUARDED_STORAGE)
 #define _TIF_ISOLATE_BP_GUEST	BIT(TIF_ISOLATE_BP_GUEST)
 #define _TIF_PER_TRAP		BIT(TIF_PER_TRAP)
-#define _TIF_SINGLESTEP	BIT(TIF_SINGLESTEP)
 #define _TIF_BLOCK_STEP		BIT(TIF_BLOCK_STEP)
 #define _TIF_UPROBE_SINGLESTEP	BIT(TIF_UPROBE_SINGLESTEP)
 
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 0067684afb5b..f59072ba1473 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -98,9 +98,8 @@ struct thread_info {
 #define TIF_IO_BITMAP		22	/* uses I/O bitmap */
 #define TIF_SPEC_FORCE_UPDATE	23	/* Force speculation MSR update in context switch */
 #define TIF_FORCED_TF		24	/* true if TF in eflags artificially */
-#define TIF_SINGLESTEP		25	/* reenable singlestep on user return*/
-#define TIF_BLOCKSTEP		26	/* set when we want DEBUGCTLMSR_BTF */
-#define TIF_ADDR32		27	/* 32-bit address space on 64 bits */
+#define TIF_BLOCKSTEP		25	/* set when we want DEBUGCTLMSR_BTF */
+#define TIF_ADDR32		26	/* 32-bit address space on 64 bits */
 
 #define _TIF_SSBD		BIT(TIF_SSBD)
 #define _TIF_SPEC_IB		BIT(TIF_SPEC_IB)
@@ -112,7 +111,6 @@ struct thread_info {
 #define _TIF_SPEC_FORCE_UPDATE	BIT(TIF_SPEC_FORCE_UPDATE)
 #define _TIF_FORCED_TF		BIT(TIF_FORCED_TF)
 #define _TIF_BLOCKSTEP		BIT(TIF_BLOCKSTEP)
-#define _TIF_SINGLESTEP		BIT(TIF_SINGLESTEP)
 #define _TIF_ADDR32		BIT(TIF_ADDR32)
 
 /* flags to check in __switch_to() */
diff --git a/include/asm-generic/thread_info_tif.h b/include/asm-generic/thread_info_tif.h
index da1610a78f92..b277fe06aee3 100644
--- a/include/asm-generic/thread_info_tif.h
+++ b/include/asm-generic/thread_info_tif.h
@@ -48,4 +48,9 @@
 #define TIF_RSEQ		11	// Run RSEQ fast path
 #define _TIF_RSEQ		BIT(TIF_RSEQ)
 
+#ifdef HAVE_TIF_SINGLESTEP
+#define TIF_SINGLESTEP		12	/* reenable singlestep on user return*/
+#define _TIF_SINGLESTEP		BIT(TIF_SINGLESTEP)
+#endif
+
 #endif /* _ASM_GENERIC_THREAD_INFO_TIF_H_ */
-- 
2.34.1

[PATCH v14 3/4] arm64: Use generic TIF bits for common thread flags

[Jinjie Ruan]

Use the generic TIF bits defined in <asm-generic/thread_info_tif.h> for
standard thread flags (TIF_SIGPENDING, TIF_NEED_RESCHED, TIF_NOTIFY_RESUME,
TIF_RESTORE_SIGMASK, TIF_SINGLESTEP, etc.) instead of defining
them locally.

Arm64-specific bits (TIF_FOREIGN_FPSTATE, TIF_MTE_ASYNC_FAULT, TIF_SVE,
TIF_SSBD, etc.) are renumbered to start at bit 16 to avoid conflicts.

This enables RSEQ optimizations which require CONFIG_HAVE_GENERIC_TIF_BITS
combined with the generic entry infrastructure (already used by arm64).

By the way, remove TIF_FREEZE because this flag became unused since
commit d88e4cb67197 ("freezer: remove now unused TIF_FREEZE").

Cc: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/arm64/Kconfig                   |  1 +
 arch/arm64/include/asm/thread_info.h | 61 ++++++++++++----------------
 2 files changed, 27 insertions(+), 35 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 96fef01598be..33cf901fb1a0 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -224,6 +224,7 @@ config ARM64
 	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
 	select HAVE_BUILDTIME_MCOUNT_SORT
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
+	select HAVE_GENERIC_TIF_BITS
 	select HAVE_GUP_FAST
 	select HAVE_FTRACE_GRAPH_FUNC
 	select HAVE_FUNCTION_TRACER
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index f89a15dc6ad5..57c37b05b961 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -58,42 +58,33 @@ void arch_setup_new_exec(void);
 
 #endif
 
-#define TIF_SIGPENDING		0	/* signal pending */
-#define TIF_NEED_RESCHED	1	/* rescheduling necessary */
-#define TIF_NEED_RESCHED_LAZY	2	/* Lazy rescheduling needed */
-#define TIF_NOTIFY_RESUME	3	/* callback before returning to user */
-#define TIF_FOREIGN_FPSTATE	4	/* CPU's FP state is not current's */
-#define TIF_UPROBE		5	/* uprobe breakpoint or singlestep */
-#define TIF_MTE_ASYNC_FAULT	6	/* MTE Asynchronous Tag Check Fault */
-#define TIF_NOTIFY_SIGNAL	7	/* signal notifications exist */
-#define TIF_PATCH_PENDING	13	/* pending live patching update */
-#define TIF_MEMDIE		18	/* is terminating due to OOM killer */
-#define TIF_FREEZE		19
-#define TIF_RESTORE_SIGMASK	20
-#define TIF_SINGLESTEP		21
-#define TIF_32BIT		22	/* 32bit process */
-#define TIF_SVE			23	/* Scalable Vector Extension in use */
-#define TIF_SVE_VL_INHERIT	24	/* Inherit SVE vl_onexec across exec */
-#define TIF_SSBD		25	/* Wants SSB mitigation */
-#define TIF_TAGGED_ADDR		26	/* Allow tagged user addresses */
-#define TIF_SME			27	/* SME in use */
-#define TIF_SME_VL_INHERIT	28	/* Inherit SME vl_onexec across exec */
-#define TIF_KERNEL_FPSTATE	29	/* Task is in a kernel mode FPSIMD section */
-#define TIF_TSC_SIGSEGV		30	/* SIGSEGV on counter-timer access */
-#define TIF_LAZY_MMU_PENDING	31	/* Ops pending for lazy mmu mode exit */
+/*
+ * Tell the generic TIF infrastructure which bits arm64 supports
+ */
+#define HAVE_TIF_NEED_RESCHED_LAZY
+#define HAVE_TIF_RESTORE_SIGMASK
+#define HAVE_TIF_SINGLESTEP
+
+#include <asm-generic/thread_info_tif.h>
+
+#define TIF_FOREIGN_FPSTATE	16	/* CPU's FP state is not current's */
+#define TIF_MTE_ASYNC_FAULT	17	/* MTE Asynchronous Tag Check Fault */
+#define TIF_32BIT		18      /* 32bit process */
+#define TIF_SVE			19	/* Scalable Vector Extension in use */
+#define TIF_SVE_VL_INHERIT	20	/* Inherit SVE vl_onexec across exec */
+#define TIF_SSBD		21	/* Wants SSB mitigation */
+#define TIF_TAGGED_ADDR		22	/* Allow tagged user addresses */
+#define TIF_SME			23	/* SME in use */
+#define TIF_SME_VL_INHERIT	24	/* Inherit SME vl_onexec across exec */
+#define TIF_KERNEL_FPSTATE	25	/* Task is in a kernel mode FPSIMD section */
+#define TIF_TSC_SIGSEGV		26	/* SIGSEGV on counter-timer access */
+#define TIF_LAZY_MMU_PENDING	27	/* Ops pending for lazy mmu mode exit */
 
-#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
-#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
-#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
-#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
-#define _TIF_FOREIGN_FPSTATE	(1 << TIF_FOREIGN_FPSTATE)
-#define _TIF_PATCH_PENDING	(1 << TIF_PATCH_PENDING)
-#define _TIF_UPROBE		(1 << TIF_UPROBE)
-#define _TIF_32BIT		(1 << TIF_32BIT)
-#define _TIF_SVE		(1 << TIF_SVE)
-#define _TIF_MTE_ASYNC_FAULT	(1 << TIF_MTE_ASYNC_FAULT)
-#define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
-#define _TIF_TSC_SIGSEGV	(1 << TIF_TSC_SIGSEGV)
+#define _TIF_FOREIGN_FPSTATE	BIT(TIF_FOREIGN_FPSTATE)
+#define _TIF_32BIT		BIT(TIF_32BIT)
+#define _TIF_SVE		BIT(TIF_SVE)
+#define _TIF_MTE_ASYNC_FAULT	BIT(TIF_MTE_ASYNC_FAULT)
+#define _TIF_TSC_SIGSEGV	BIT(TIF_TSC_SIGSEGV)
 
 #ifdef CONFIG_SHADOW_CALL_STACK
 #define INIT_SCS							\
-- 
2.34.1

Re: [PATCH v14 3/4] arm64: Use generic TIF bits for common thread flags

[Catalin Marinas]

On Fri, Mar 20, 2026 at 06:42:21PM +0800, Jinjie Ruan wrote:
> Use the generic TIF bits defined in <asm-generic/thread_info_tif.h> for
> standard thread flags (TIF_SIGPENDING, TIF_NEED_RESCHED, TIF_NOTIFY_RESUME,
> TIF_RESTORE_SIGMASK, TIF_SINGLESTEP, etc.) instead of defining
> them locally.
> 
> Arm64-specific bits (TIF_FOREIGN_FPSTATE, TIF_MTE_ASYNC_FAULT, TIF_SVE,
> TIF_SSBD, etc.) are renumbered to start at bit 16 to avoid conflicts.
> 
> This enables RSEQ optimizations which require CONFIG_HAVE_GENERIC_TIF_BITS
> combined with the generic entry infrastructure (already used by arm64).
> 
> By the way, remove TIF_FREEZE because this flag became unused since
> commit d88e4cb67197 ("freezer: remove now unused TIF_FREEZE").
> 
> Cc: Thomas Gleixner <tglx@kernel.org>
> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
> Reviewed-by: Linus Walleij <linusw@kernel.org>
> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

Given that it's touching multiple trees, I guess it's a series for
Andrew?

-- 
Catalin

Re: [PATCH v14 3/4] arm64: Use generic TIF bits for common thread flags

[Jinjie Ruan]

On 2026/4/1 18:55, Catalin Marinas wrote:
> On Fri, Mar 20, 2026 at 06:42:21PM +0800, Jinjie Ruan wrote:
>> Use the generic TIF bits defined in <asm-generic/thread_info_tif.h> for
>> standard thread flags (TIF_SIGPENDING, TIF_NEED_RESCHED, TIF_NOTIFY_RESUME,
>> TIF_RESTORE_SIGMASK, TIF_SINGLESTEP, etc.) instead of defining
>> them locally.
>>
>> Arm64-specific bits (TIF_FOREIGN_FPSTATE, TIF_MTE_ASYNC_FAULT, TIF_SVE,
>> TIF_SSBD, etc.) are renumbered to start at bit 16 to avoid conflicts.
>>
>> This enables RSEQ optimizations which require CONFIG_HAVE_GENERIC_TIF_BITS
>> combined with the generic entry infrastructure (already used by arm64).
>>
>> By the way, remove TIF_FREEZE because this flag became unused since
>> commit d88e4cb67197 ("freezer: remove now unused TIF_FREEZE").
>>
>> Cc: Thomas Gleixner <tglx@kernel.org>
>> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
>> Reviewed-by: Linus Walleij <linusw@kernel.org>
>> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> 
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> 
> Given that it's touching multiple trees, I guess it's a series for
> Andrew?

Yes, this series touches x86, arm64, s390 and loongarch. It's best for
Andrew to help merge this in the -mm tree.

Moreover, the latter two arm64-related patches depend on patch serise
"arm64:
entry: Convert to Generic Entry" v14 being merged first, while the first
two patches can be merged in advance.

> 

[PATCH v14 4/4] selftests: sud_test: Support aarch64

[Jinjie Ruan]

From: kemal <kmal@cock.li>

Support aarch64 to test "Syscall User Dispatch" feature with
sud_test selftest testcase.

On qemu-kvm machine, the sud_benchmark test results are as below:

	# ./sud_benchmark
	Calibrating test set to last ~5 seconds...
	test iterations = 24500000
	Avg syscall time 208ns.
	Enabling syscall trapping.
	Caught sys_1c2
	trapped_call_count 1, native_call_count 0.
	Avg syscall time 213ns.
	Interception overhead: 2.5% (+5ns).

Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: kemal <kmal@cock.li>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 tools/testing/selftests/syscall_user_dispatch/sud_benchmark.c | 2 +-
 tools/testing/selftests/syscall_user_dispatch/sud_test.c      | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/syscall_user_dispatch/sud_benchmark.c b/tools/testing/selftests/syscall_user_dispatch/sud_benchmark.c
index 073a03702ff5..6059abe75cb3 100644
--- a/tools/testing/selftests/syscall_user_dispatch/sud_benchmark.c
+++ b/tools/testing/selftests/syscall_user_dispatch/sud_benchmark.c
@@ -41,7 +41,7 @@
  * out of the box, but don't enable them until they support syscall user
  * dispatch.
  */
-#if defined(__x86_64__) || defined(__i386__)
+#if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__)
 #define TEST_BLOCKED_RETURN
 #endif
 
diff --git a/tools/testing/selftests/syscall_user_dispatch/sud_test.c b/tools/testing/selftests/syscall_user_dispatch/sud_test.c
index b855c6000287..3ffea2f4a66d 100644
--- a/tools/testing/selftests/syscall_user_dispatch/sud_test.c
+++ b/tools/testing/selftests/syscall_user_dispatch/sud_test.c
@@ -192,6 +192,10 @@ static void handle_sigsys(int sig, siginfo_t *info, void *ucontext)
 	((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A0] =
 			((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A7];
 #endif
+#ifdef __aarch64__
+	((ucontext_t *)ucontext)->uc_mcontext.regs[0] = (unsigned int)
+			((ucontext_t *)ucontext)->uc_mcontext.regs[8];
+#endif
 }
 
 int setup_sigsys_handler(void)
-- 
2.34.1

Re: [PATCH v14 4/4] selftests: sud_test: Support aarch64

[Linus Walleij]

On Fri, Mar 20, 2026 at 11:41 AM Jinjie Ruan <ruanjinjie@huawei.com> wrote:

> From: kemal <kmal@cock.li>
>
> Support aarch64 to test "Syscall User Dispatch" feature with
> sud_test selftest testcase.
>
> On qemu-kvm machine, the sud_benchmark test results are as below:
>
>         # ./sud_benchmark
>         Calibrating test set to last ~5 seconds...
>         test iterations = 24500000
>         Avg syscall time 208ns.
>         Enabling syscall trapping.
>         Caught sys_1c2
>         trapped_call_count 1, native_call_count 0.
>         Avg syscall time 213ns.
>         Interception overhead: 2.5% (+5ns).
>
> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
> Signed-off-by: kemal <kmal@cock.li>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij