Commit 6bfce775 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'core-entry-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull core entry code update from Thomas Gleixner:
 "A single update to the core entry code, which removes the empty user
  address limit check which is a leftover of the removed TIF_FSCHECK"

* tag 'core-entry-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Remove empty addr_limit_user_check()
parents b98af53c 1dfe3a5a

include/linux/syscalls.h

+0 −16
Original line number Diff line number Diff line
@@ -283,22 +283,6 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) 
#define SYSCALL32_DEFINE6 SYSCALL_DEFINE6

#endif



/*

 * Called before coming back to user-mode. Returning to user-mode with an

 * address limit different than USER_DS can allow to overwrite kernel memory.

 */

static inline void addr_limit_user_check(void)

{

#ifdef TIF_FSCHECK

	if (!test_thread_flag(TIF_FSCHECK))

		return;

#endif



#ifdef TIF_FSCHECK

	clear_thread_flag(TIF_FSCHECK);

#endif

}



/*

 * These syscall function prototypes are kept in the same order as

 * include/uapi/asm-generic/unistd.h. Architecture specific entries go below,

kernel/entry/common.c

+1 −2
Original line number Diff line number Diff line
@@ -205,8 +205,7 @@ static void exit_to_user_mode_prepare(struct pt_regs *regs) 


	arch_exit_to_user_mode_prepare(regs, ti_work);



	/* Ensure that the address limit is intact and no locks are held */

	addr_limit_user_check();

	/* Ensure that kernel state is sane for a return to userspace */

	kmap_assert_nomap();

	lockdep_assert_irqs_disabled();

	lockdep_sys_exit();