[PATCH v6 23/27] unicore32: add asm/syscall.h

[Dmitry V. Levin]

syscall_get_* functions are required to be implemented on all
architectures in order to extend the generic ptrace API with
PTRACE_GET_SYSCALL_INFO request.

This introduces asm/syscall.h on unicore32 implementing all 5
syscall_get_* functions as documented in asm-generic/syscall.h:
syscall_get_nr, syscall_get_arguments, syscall_get_error,
syscall_get_return_value, and syscall_get_arch.

A note for the unicore32 architecture maintainer: I have no idea about
the syscall semantics on this architecture, and the code is of little
help here.  All I could infer from the code is that it looks very
similar to ARM, so the implementation of syscall_get_* functions
is also similar to ARM.

Cc: Guan Xuetao <gxt@xxxxxxxxxx>
Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
Cc: Eric Paris <eparis@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Elvira Khabirova <lineprinter@xxxxxxxxxxxx>
Cc: Eugene Syromyatnikov <esyr@xxxxxxxxxx>
Cc: linux-audit@xxxxxxxxxx
Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
---

Notes:
    v6: made use of asm-generic/syscall.h
    v5: added syscall_get_nr, syscall_get_arguments, syscall_get_error,
        and syscall_get_return_value
    v1: added syscall_get_arch

 arch/unicore32/include/asm/syscall.h | 46 ++++++++++++++++++++++++++++
 include/uapi/linux/audit.h           |  1 +
 2 files changed, 47 insertions(+)
 create mode 100644 arch/unicore32/include/asm/syscall.h

diff --git a/arch/unicore32/include/asm/syscall.h b/arch/unicore32/include/asm/syscall.h
new file mode 100644
index 000000000000..267e97e256bd
--- /dev/null
+++ b/arch/unicore32/include/asm/syscall.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_UNICORE_SYSCALL_H
+#define _ASM_UNICORE_SYSCALL_H
+
+#include <linux/err.h>
+#include <asm/ptrace.h>
+#include <asm-generic/syscall.h>
+#include <uapi/linux/audit.h>
+
+static inline int
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+	return task_thread_info(task)->syscall;
+}
+
+static inline void
+__syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+			unsigned int i, unsigned int n, unsigned long *args)
+{
+	if (i == 0) {
+		args[0] = regs->UCreg_ORIG_00;
+		args++;
+		i++;
+		n--;
+	}
+	memcpy(args, &regs->UCreg_00 + i, n * sizeof(args[0]));
+}
+
+static inline long
+syscall_get_error(struct task_struct *task, struct pt_regs *regs)
+{
+	return IS_ERR_VALUE(regs->UCreg_00) ? regs->UCreg_00 : 0;
+}
+
+static inline long
+syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs->UCreg_00;
+}
+
+static inline int
+syscall_get_arch(void)
+{
+	return AUDIT_ARCH_UNICORE;
+}
+
+#endif	/* _ASM_UNICORE_SYSCALL_H */
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index bcc0619b046f..3901c51c0b93 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -424,6 +424,7 @@ enum {
 #define AUDIT_ARCH_TILEGX	(EM_TILEGX|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_TILEGX32	(EM_TILEGX|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_TILEPRO	(EM_TILEPRO|__AUDIT_ARCH_LE)
+#define AUDIT_ARCH_UNICORE	(EM_UNICORE|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_X86_64	(EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_XTENSA	(EM_XTENSA)
 
-- 
ldv