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

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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()
This commit is contained in:
Linus Torvalds
2023-08-28 14:04:55 -07:00
parent b98af53cb0 1dfe3a5a7c
commit 6bfce7759c
2 changed files with 1 additions and 18 deletions
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16
include/linux/syscalls.h
View File

@ -283,22 +283,6 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
#define SYSCALL32_DEFINE6 SYSCALL_DEFINE6 #define SYSCALL32_DEFINE6 SYSCALL_DEFINE6
#endif #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 * These syscall function prototypes are kept in the same order as
* include/uapi/asm-generic/unistd.h. Architecture specific entries go below, * include/uapi/asm-generic/unistd.h. Architecture specific entries go below,

3
kernel/entry/common.c
View File

@ -205,8 +205,7 @@ static void exit_to_user_mode_prepare(struct pt_regs *regs)
arch_exit_to_user_mode_prepare(regs, ti_work); arch_exit_to_user_mode_prepare(regs, ti_work);
/* Ensure that the address limit is intact and no locks are held */ /* Ensure that kernel state is sane for a return to userspace */
addr_limit_user_check();
kmap_assert_nomap(); kmap_assert_nomap();
lockdep_assert_irqs_disabled(); lockdep_assert_irqs_disabled();
lockdep_sys_exit(); lockdep_sys_exit();