From 1dfe3a5a7cefbe2162cecb759f3933baea22c393 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 21 Aug 2023 17:35:26 +0100 Subject: entry: Remove empty addr_limit_user_check() Back when set_fs() was a generic API for altering the address limit, addr_limit_user_check() was a safety measure to prevent userspace being able to issue syscalls with an unbound limit. With the the removal of set_fs() as a generic API, the last user of addr_limit_user_check() was removed in commit: b5a5a01d8e9a44ec ("arm64: uaccess: remove addr_limit_user_check()") ... as since that commit, no architecture defines TIF_FSCHECK, and hence addr_limit_user_check() always expands to nothing. Remove addr_limit_user_check(), updating the comment in exit_to_user_mode_prepare() to no longer refer to it. At the same time, the comment is reworded to be a little more generic so as to cover kmap_assert_nomap() in addition to lockdep_sys_exit(). No functional change. Signed-off-by: Mark Rutland Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230821163526.2319443-1-mark.rutland@arm.com --- kernel/entry/common.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel/entry/common.c') diff --git a/kernel/entry/common.c b/kernel/entry/common.c index be61332c66b5..d7ee4bc3f2ba 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -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(); -- cgit v1.2.3