From: John David Anglin dave.anglin@bell.net
stable inclusion from stable-v5.10.94 commit 3681e9f3f0f7df9a3821b02fadf17a669681ea43 bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 9e9d4b460f23bab61672eae397417d03917d116c ]
In handle_interruption(), we call faulthandler_disabled() to check whether the fault handler is not disabled. If the fault handler is disabled, we immediately call do_page_fault(). It then calls faulthandler_disabled(). If disabled, do_page_fault() attempts to fixup the exception by jumping to no_context:
no_context:
if (!user_mode(regs) && fixup_exception(regs)) { return; }
parisc_terminate("Bad Address (null pointer deref?)", regs, code, address);
Apart from the error messages, the two blocks of code perform the same function.
We can avoid two calls to faulthandler_disabled() by a simple revision to the code in handle_interruption().
Note: I didn't try to fix the formatting of this code block.
Signed-off-by: John David Anglin dave.anglin@bell.net Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- arch/parisc/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index 43f56335759a..269b737d2629 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -784,7 +784,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs) * unless pagefault_disable() was called before. */
- if (fault_space == 0 && !faulthandler_disabled()) + if (faulthandler_disabled() || fault_space == 0) { /* Clean up and return if in exception table. */ if (fixup_exception(regs))