Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
to use the generic entry infrastructure from kernel/entry/*.
The generic entry makes maintainers' work easier and codes more elegant.
The changes are below:
- Remove TIF_SYSCALL_* flag, _TIF_WORK_MASK, _TIF_SYSCALL_WORK
- Remove syscall_trace_enter/exit() and use generic identical functions.
Tested ok with following test cases on Qemu virt platform:
- Perf tests.
- Different `dynamic preempt` mode switch.
- Pseudo NMI tests.
- Stress-ng CPU stress test.
- MTE test case in Documentation/arch/arm64/memory-tagging-extension.rst
and all test cases in tools/testing/selftests/arm64/mte/*.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
v5:
- Rebased on the previous patch udapte.
- Define ARCH_SYSCALL_WORK_EXIT.
---
arch/arm64/Kconfig | 2 +-
arch/arm64/include/asm/entry-common.h | 70 ++++++++++++++
arch/arm64/include/asm/syscall.h | 7 +-
arch/arm64/include/asm/thread_info.h | 23 +----
arch/arm64/kernel/debug-monitors.c | 7 ++
arch/arm64/kernel/ptrace.c | 134 --------------------------
arch/arm64/kernel/signal.c | 2 +-
arch/arm64/kernel/syscall.c | 6 +-
8 files changed, 87 insertions(+), 164 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3751ab9f2a21..a1d96712428e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -148,9 +148,9 @@ config ARM64
select GENERIC_CPU_DEVICES
select GENERIC_CPU_VULNERABILITIES
select GENERIC_EARLY_IOREMAP
+ select GENERIC_ENTRY
select GENERIC_IDLE_POLL_SETUP
select GENERIC_IOREMAP
- select GENERIC_IRQ_ENTRY
select GENERIC_IRQ_IPI
select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
select GENERIC_IRQ_PROBE
diff --git a/arch/arm64/include/asm/entry-common.h b/arch/arm64/include/asm/entry-common.h
index 1cc9d966a6c3..6082393c61f2 100644
--- a/arch/arm64/include/asm/entry-common.h
+++ b/arch/arm64/include/asm/entry-common.h
@@ -10,6 +10,12 @@
#include <asm/mte.h>
#include <asm/stacktrace.h>
+enum ptrace_syscall_dir {
+ PTRACE_SYSCALL_ENTER = 0,
+ PTRACE_SYSCALL_EXIT,
+};
+
+#define ARCH_SYSCALL_WORK_EXIT (SYSCALL_WORK_SECCOMP | SYSCALL_WORK_SYSCALL_EMU)
#define ARCH_EXIT_TO_USER_MODE_WORK (_TIF_MTE_ASYNC_FAULT | _TIF_FOREIGN_FPSTATE)
static __always_inline void arch_exit_to_user_mode_work(struct pt_regs *regs,
@@ -61,4 +67,68 @@ static inline bool arch_irqentry_exit_need_resched(void)
#define arch_irqentry_exit_need_resched arch_irqentry_exit_need_resched
+static inline int arch_ptrace_report_syscall_entry(struct pt_regs *regs)
+{
+ unsigned long saved_reg;
+ int regno, ret;
+
+ /*
+ * We have some ABI weirdness here in the way that we handle syscall
+ * exit stops because we indicate whether or not the stop has been
+ * signalled from syscall entry or syscall exit by clobbering a general
+ * purpose register (ip/r12 for AArch32, x7 for AArch64) in the tracee
+ * and restoring its old value after the stop. This means that:
+ *
+ * - Any writes by the tracer to this register during the stop are
+ * ignored/discarded.
+ *
+ * - The actual value of the register is not available during the stop,
+ * so the tracer cannot save it and restore it later.
+ *
+ * - Syscall stops behave differently to seccomp and pseudo-step traps
+ * (the latter do not nobble any registers).
+ */
+ regno = (is_compat_task() ? 12 : 7);
+ saved_reg = regs->regs[regno];
+ regs->regs[regno] = PTRACE_SYSCALL_ENTER;
+
+ ret = ptrace_report_syscall_entry(regs);
+ if (ret)
+ forget_syscall(regs);
+
+ regs->regs[regno] = saved_reg;
+
+ return ret;
+}
+
+#define arch_ptrace_report_syscall_entry arch_ptrace_report_syscall_entry
+
+static inline void arch_ptrace_report_syscall_exit(struct pt_regs *regs,
+ int step)
+{
+ unsigned long saved_reg;
+ int regno;
+
+ /* See comment for arch_ptrace_report_syscall_entry() */
+ regno = (is_compat_task() ? 12 : 7);
+ saved_reg = regs->regs[regno];
+ regs->regs[regno] = PTRACE_SYSCALL_EXIT;
+
+ if (!test_thread_flag(TIF_SINGLESTEP)) {
+ ptrace_report_syscall_exit(regs, 0);
+ regs->regs[regno] = saved_reg;
+ } else {
+ regs->regs[regno] = saved_reg;
+
+ /*
+ * Signal a pseudo-step exception since we are stepping but
+ * tracer modifications to the registers may have rewound the
+ * state machine.
+ */
+ ptrace_report_syscall_exit(regs, 1);
+ }
+}
+
+#define arch_ptrace_report_syscall_exit arch_ptrace_report_syscall_exit
+
#endif /* _ASM_ARM64_ENTRY_COMMON_H */
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 6eeb1e7b033f..9891b15da4c3 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -85,12 +85,9 @@ static inline int syscall_get_arch(struct task_struct *task)
return AUDIT_ARCH_AARCH64;
}
-static inline bool has_syscall_work(unsigned long flags)
+static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
{
- return unlikely(flags & _TIF_SYSCALL_WORK);
+ return false;
}
-int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long flags);
-void syscall_exit_to_user_mode_prepare(struct pt_regs *regs);
-
#endif /* __ASM_SYSCALL_H */
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 1114c1c3300a..543fdb00d713 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -43,6 +43,7 @@ struct thread_info {
void *scs_sp;
#endif
u32 cpu;
+ unsigned long syscall_work; /* SYSCALL_WORK_ flags */
};
#define thread_saved_pc(tsk) \
@@ -64,11 +65,6 @@ void arch_setup_new_exec(void);
#define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */
#define TIF_MTE_ASYNC_FAULT 5 /* MTE Asynchronous Tag Check Fault */
#define TIF_NOTIFY_SIGNAL 6 /* signal notifications exist */
-#define TIF_SYSCALL_TRACE 8 /* syscall trace active */
-#define TIF_SYSCALL_AUDIT 9 /* syscall auditing */
-#define TIF_SYSCALL_TRACEPOINT 10 /* syscall tracepoint for ftrace */
-#define TIF_SECCOMP 11 /* syscall secure computing */
-#define TIF_SYSCALL_EMU 12 /* syscall emulation active */
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_FREEZE 19
#define TIF_RESTORE_SIGMASK 20
@@ -87,28 +83,13 @@ void arch_setup_new_exec(void);
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_FOREIGN_FPSTATE (1 << TIF_FOREIGN_FPSTATE)
-#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
-#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
-#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
-#define _TIF_SECCOMP (1 << TIF_SECCOMP)
-#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
-#define _TIF_UPROBE (1 << TIF_UPROBE)
-#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
+#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_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
- _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
- _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \
- _TIF_NOTIFY_SIGNAL)
-
-#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
- _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
- _TIF_SYSCALL_EMU)
-
#ifdef CONFIG_SHADOW_CALL_STACK
#define INIT_SCS \
.scs_base = init_shadow_call_stack, \
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 460c09d03a73..95b70555a1a8 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -452,11 +452,18 @@ void user_enable_single_step(struct task_struct *task)
if (!test_and_set_ti_thread_flag(ti, TIF_SINGLESTEP))
set_regs_spsr_ss(task_pt_regs(task));
+
+ /*
+ * Ensure that a trap is triggered once stepping out of a system
+ * call prior to executing any user instruction.
+ */
+ set_task_syscall_work(task, SYSCALL_EXIT_TRAP);
}
NOKPROBE_SYMBOL(user_enable_single_step);
void user_disable_single_step(struct task_struct *task)
{
clear_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
+ clear_task_syscall_work(task, SYSCALL_EXIT_TRAP);
}
NOKPROBE_SYMBOL(user_disable_single_step);
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 3a7a1eaca0a9..a09058b9b7fb 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -42,9 +42,6 @@
#include <asm/traps.h>
#include <asm/system_misc.h>
-#define CREATE_TRACE_POINTS
-#include <trace/events/syscalls.h>
-
struct pt_regs_offset {
const char *name;
int offset;
@@ -2293,137 +2290,6 @@ long arch_ptrace(struct task_struct *child, long request,
return ptrace_request(child, request, addr, data);
}
-enum ptrace_syscall_dir {
- PTRACE_SYSCALL_ENTER = 0,
- PTRACE_SYSCALL_EXIT,
-};
-
-static int report_syscall_enter(struct pt_regs *regs)
-{
- unsigned long saved_reg;
- int regno, ret;
-
- /*
- * We have some ABI weirdness here in the way that we handle syscall
- * exit stops because we indicate whether or not the stop has been
- * signalled from syscall entry or syscall exit by clobbering a general
- * purpose register (ip/r12 for AArch32, x7 for AArch64) in the tracee
- * and restoring its old value after the stop. This means that:
- *
- * - Any writes by the tracer to this register during the stop are
- * ignored/discarded.
- *
- * - The actual value of the register is not available during the stop,
- * so the tracer cannot save it and restore it later.
- *
- * - Syscall stops behave differently to seccomp and pseudo-step traps
- * (the latter do not nobble any registers).
- */
- regno = (is_compat_task() ? 12 : 7);
- saved_reg = regs->regs[regno];
- regs->regs[regno] = PTRACE_SYSCALL_ENTER;
-
- ret = ptrace_report_syscall_entry(regs);
- if (ret)
- forget_syscall(regs);
-
- regs->regs[regno] = saved_reg;
-
- return ret;
-}
-
-static void report_syscall_exit(struct pt_regs *regs)
-{
- int regno;
- unsigned long saved_reg;
-
- /* See comment for report_syscall_enter() */
- regno = (is_compat_task() ? 12 : 7);
- saved_reg = regs->regs[regno];
- regs->regs[regno] = PTRACE_SYSCALL_EXIT;
-
- if (!test_thread_flag(TIF_SINGLESTEP)) {
- ptrace_report_syscall_exit(regs, 0);
- regs->regs[regno] = saved_reg;
- } else {
- regs->regs[regno] = saved_reg;
-
- /*
- * Signal a pseudo-step exception since we are stepping but
- * tracer modifications to the registers may have rewound the
- * state machine.
- */
- ptrace_report_syscall_exit(regs, 1);
- }
-}
-
-static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
-{
- if (unlikely(audit_context())) {
- unsigned long args[6];
-
- syscall_get_arguments(current, regs, args);
- audit_syscall_entry(syscall, args[0], args[1], args[2], args[3]);
- }
-
-}
-
-int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long flags)
-{
- int ret;
-
- if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
- ret = report_syscall_enter(regs);
- if (ret || (flags & _TIF_SYSCALL_EMU))
- return NO_SYSCALL;
- }
-
- /* Do the secure computing after ptrace; failures should be fast. */
- if (flags & _TIF_SECCOMP) {
- ret = __secure_computing(NULL);
- if (ret == -1L)
- return NO_SYSCALL;
- }
-
- /* Either of the above might have changed the syscall number */
- syscall = syscall_get_nr(current, regs);
-
- if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) {
- trace_sys_enter(regs, syscall);
-
- /*
- * Probes or BPF hooks in the tracepoint may have changed the
- * system call number as well.
- */
- syscall = syscall_get_nr(current, regs);
- }
-
- syscall_enter_audit(regs, syscall);
-
- return regs->syscallno;
-}
-
-static void syscall_trace_exit(struct pt_regs *regs, unsigned long flags)
-{
- audit_syscall_exit(regs);
-
- if (flags & _TIF_SYSCALL_TRACEPOINT)
- trace_sys_exit(regs, syscall_get_return_value(current, regs));
-
- if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP))
- report_syscall_exit(regs);
-}
-
-void syscall_exit_to_user_mode_prepare(struct pt_regs *regs)
-{
- unsigned long flags = read_thread_flags();
-
- rseq_syscall(regs);
-
- if (has_syscall_work(flags) || flags & _TIF_SINGLESTEP)
- syscall_trace_exit(regs, flags);
-}
-
/*
* SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a.
* We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which is
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 84b6628647c7..6cc8fe19e6a0 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -8,8 +8,8 @@
#include <linux/cache.h>
#include <linux/compat.h>
+#include <linux/entry-common.h>
#include <linux/errno.h>
-#include <linux/irq-entry-common.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/freezer.h>
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index a50db885fc34..5aa585111c4b 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -2,6 +2,7 @@
#include <linux/compiler.h>
#include <linux/context_tracking.h>
+#include <linux/entry-common.h>
#include <linux/errno.h>
#include <linux/nospec.h>
#include <linux/ptrace.h>
@@ -68,6 +69,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno,
static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
const syscall_fn_t syscall_table[])
{
+ unsigned long work = READ_ONCE(current_thread_info()->syscall_work);
unsigned long flags = read_thread_flags();
regs->orig_x0 = regs->regs[0];
@@ -101,7 +103,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
return;
}
- if (has_syscall_work(flags)) {
+ if (has_syscall_work(work)) {
/*
* The de-facto standard way to skip a system call using ptrace
* is to set the system call to -1 (NO_SYSCALL) and set x0 to a
@@ -119,7 +121,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
*/
if (scno == NO_SYSCALL)
syscall_set_return_value(current, regs, -ENOSYS, 0);
- scno = syscall_trace_enter(regs, regs->syscallno, flags);
+ scno = syscall_trace_enter(regs, regs->syscallno, work);
if (scno == NO_SYSCALL) {
syscall_exit_to_user_mode_prepare(regs);
return;
--
2.34.1