1 files changed, 32 insertions, 66 deletions

diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 709a574468f0..4cfe9b49709b 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -1,17 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #ifndef __ASM_SYSCALL_H
 #define __ASM_SYSCALL_H
@@ -20,7 +9,13 @@
 #include <linux/compat.h>
 #include <linux/err.h>
 
-extern const void *sys_call_table[];
+typedef long (*syscall_fn_t)(const struct pt_regs *regs);
+
+extern const syscall_fn_t sys_call_table[];
+
+#ifdef CONFIG_COMPAT
+extern const syscall_fn_t compat_sys_call_table[];
+#endif
 
 static inline int syscall_get_nr(struct task_struct *task,
 				 struct pt_regs *regs)
@@ -34,86 +29,57 @@ static inline void syscall_rollback(struct task_struct *task,
 	regs->regs[0] = regs->orig_x0;
 }
 
+static inline long syscall_get_return_value(struct task_struct *task,
+					    struct pt_regs *regs)
+{
+	unsigned long val = regs->regs[0];
+
+	if (is_compat_thread(task_thread_info(task)))
+		val = sign_extend64(val, 31);
+
+	return val;
+}
 
 static inline long syscall_get_error(struct task_struct *task,
 				     struct pt_regs *regs)
 {
-	unsigned long error = regs->regs[0];
-	return IS_ERR_VALUE(error) ? error : 0;
-}
+	unsigned long error = syscall_get_return_value(task, regs);
 
-static inline long syscall_get_return_value(struct task_struct *task,
-					    struct pt_regs *regs)
-{
-	return regs->regs[0];
+	return IS_ERR_VALUE(error) ? error : 0;
 }
 
 static inline void syscall_set_return_value(struct task_struct *task,
 					    struct pt_regs *regs,
 					    int error, long val)
 {
-	regs->regs[0] = (long) error ? error : val;
+	if (error)
+		val = error;
+
+	if (is_compat_thread(task_thread_info(task)))
+		val = lower_32_bits(val);
+
+	regs->regs[0] = val;
 }
 
 #define SYSCALL_MAX_ARGS 6
 
 static inline void syscall_get_arguments(struct task_struct *task,
 					 struct pt_regs *regs,
-					 unsigned int i, unsigned int n,
 					 unsigned long *args)
 {
-	if (n == 0)
-		return;
-
-	if (i + n > SYSCALL_MAX_ARGS) {
-		unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
-		unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
-		pr_warning("%s called with max args %d, handling only %d\n",
-			   __func__, i + n, SYSCALL_MAX_ARGS);
-		memset(args_bad, 0, n_bad * sizeof(args[0]));
-	}
-
-	if (i == 0) {
-		args[0] = regs->orig_x0;
-		args++;
-		i++;
-		n--;
-	}
-
-	memcpy(args, &regs->regs[i], n * sizeof(args[0]));
-}
+	args[0] = regs->orig_x0;
+	args++;
 
-static inline void syscall_set_arguments(struct task_struct *task,
-					 struct pt_regs *regs,
-					 unsigned int i, unsigned int n,
-					 const unsigned long *args)
-{
-	if (n == 0)
-		return;
-
-	if (i + n > SYSCALL_MAX_ARGS) {
-		pr_warning("%s called with max args %d, handling only %d\n",
-			   __func__, i + n, SYSCALL_MAX_ARGS);
-		n = SYSCALL_MAX_ARGS - i;
-	}
-
-	if (i == 0) {
-		regs->orig_x0 = args[0];
-		args++;
-		i++;
-		n--;
-	}
-
-	memcpy(&regs->regs[i], args, n * sizeof(args[0]));
+	memcpy(args, &regs->regs[1], 5 * sizeof(args[0]));
 }
 
 /*
  * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
  * AArch64 has the same system calls both on little- and big- endian.
  */
-static inline int syscall_get_arch(void)
+static inline int syscall_get_arch(struct task_struct *task)
 {
-	if (is_compat_task())
+	if (is_compat_thread(task_thread_info(task)))
 		return AUDIT_ARCH_ARM;
 
 	return AUDIT_ARCH_AARCH64;