xtensa: implement tracehook functions and enable HAVE_ARCH_TRACEHOOK

Implement syscall_get_nr, syscall_rollback, syscall_get_error,
syscall_{get,set}_return_value and syscall_{get,set}_arguments.
Select HAVE_ARCH_TRACEHOOK as Xtensa now has all support for that.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index d29b7365da8d9facd71a887a071b34bbb68ec5fc..55d13b589ff3e462fc9697e4a0ba0bdb734c8431 100644 (file)
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -18,6 +18,7 @@ config XTENSA
        select GENERIC_SCHED_CLOCK
        select GENERIC_STRNCPY_FROM_USER if KASAN
        select HAVE_ARCH_KASAN if MMU
+       select HAVE_ARCH_TRACEHOOK
        select HAVE_DEBUG_KMEMLEAK
        select HAVE_DMA_CONTIGUOUS
        select HAVE_EXIT_THREAD

diff --git a/arch/xtensa/include/asm/syscall.h b/arch/xtensa/include/asm/syscall.h
index 6969956d3f935cdcd0303b9f0b6efc7b5fb9699d..e47470ec8ea8d8bd09a33a8751b18d78e9b199e9 100644 (file)
--- a/arch/xtensa/include/asm/syscall.h
+++ b/arch/xtensa/include/asm/syscall.h
@@ -10,6 +10,8 @@
 #ifndef _ASM_SYSCALL_H
 #define _ASM_SYSCALL_H
 
+#include <linux/err.h>
+#include <asm/ptrace.h>
 #include <uapi/linux/audit.h>
 
 static inline int syscall_get_arch(void)
@@ -17,7 +19,83 @@ static inline int syscall_get_arch(void)
        return AUDIT_ARCH_XTENSA;
 }
 
-struct pt_regs;
+static inline long syscall_get_nr(struct task_struct *task,
+                                 struct pt_regs *regs)
+{
+       return regs->syscall;
+}
+
+static inline void syscall_rollback(struct task_struct *task,
+                                   struct pt_regs *regs)
+{
+       /* Do nothing. */
+}
+
+static inline long syscall_get_error(struct task_struct *task,
+                                    struct pt_regs *regs)
+{
+       /* 0 if syscall succeeded, otherwise -Errorcode */
+       return IS_ERR_VALUE(regs->areg[2]) ? regs->areg[2] : 0;
+}
+
+static inline long syscall_get_return_value(struct task_struct *task,
+                                           struct pt_regs *regs)
+{
+       return regs->areg[2];
+}
+
+static inline void syscall_set_return_value(struct task_struct *task,
+                                           struct pt_regs *regs,
+                                           int error, long val)
+{
+       regs->areg[0] = (long) error ? error : val;
+}
+
+#define SYSCALL_MAX_ARGS 6
+#define XTENSA_SYSCALL_ARGUMENT_REGS {6, 3, 4, 5, 8, 9}
+
+static inline void syscall_get_arguments(struct task_struct *task,
+                                        struct pt_regs *regs,
+                                        unsigned int i, unsigned int n,
+                                        unsigned long *args)
+{
+       static const unsigned int reg[] = XTENSA_SYSCALL_ARGUMENT_REGS;
+       unsigned int j;
+
+       if (n == 0)
+               return;
+
+       WARN_ON_ONCE(i + n > SYSCALL_MAX_ARGS);
+
+       for (j = 0; j < n; ++j) {
+               if (i + j < SYSCALL_MAX_ARGS)
+                       args[j] = regs->areg[reg[i + j]];
+               else
+                       args[j] = 0;
+       }
+}
+
+static inline void syscall_set_arguments(struct task_struct *task,
+                                        struct pt_regs *regs,
+                                        unsigned int i, unsigned int n,
+                                        const unsigned long *args)
+{
+       static const unsigned int reg[] = XTENSA_SYSCALL_ARGUMENT_REGS;
+       unsigned int j;
+
+       if (n == 0)
+               return;
+
+       if (WARN_ON_ONCE(i + n > SYSCALL_MAX_ARGS)) {
+               if (i < SYSCALL_MAX_ARGS)
+                       n = SYSCALL_MAX_ARGS - i;
+               else
+                       return;
+       }
+
+       for (j = 0; j < n; ++j)
+               regs->areg[reg[i + j]] = args[j];
+}
 
 asmlinkage long xtensa_rt_sigreturn(struct pt_regs*);
 asmlinkage long xtensa_shmat(int, char __user *, int);