[patch V3 07/13] x86/ptrace: Provide pt_regs helpers for entry/exit

[Thomas Gleixner]

As a preparatory step for moving the syscall and interrupt entry/exit
handling into generic code, provide pt_regs helpers which allow to:

  - Retrieve the syscall number from pt_regs
  - Retrieve the syscall return value from pt_regs
  - Retrieve the interrupt state from pt_regs to check whether interrupts
    are reenabled by return from interrupt/exception.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
 arch/x86/include/asm/ptrace.h |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -209,6 +209,21 @@ static inline void user_stack_pointer_se
        regs->sp = val;
 }
 
+static inline unsigned long regs_syscall_nr(struct pt_regs *regs)
+{
+       return regs->orig_ax;
+}
+
+static inline long regs_syscall_retval(struct pt_regs *regs)
+{
+       return regs->ax;
+}
+
+static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
+{
+       return !(regs->flags & X86_EFLAGS_IF);
+}
+
 /* Query offset/name of register from its name/offset */
 extern int regs_query_register_offset(const char *name);
 extern const char *regs_query_register_name(unsigned int offset);