From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Yonghong Song <yhs@fb.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v2 05/14] x86/fault: Document the locking in the fault_signal_pending() path
Date: Tue, 9 Feb 2021 18:33:37 -0800 [thread overview]
Message-ID: <c56de3d103f40e6304437b150aa7b215530d23f7.1612924255.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1612924255.git.luto@kernel.org>
If fault_signal_pending() returns true, then the core mm has unlocked the
mm for us. Add a comment to help future readers of this code.
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/mm/fault.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 3ffed003f281..013910b7b93f 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1380,8 +1380,11 @@ void do_user_addr_fault(struct pt_regs *regs,
*/
fault = handle_mm_fault(vma, address, flags, regs);
- /* Quick path to respond to signals */
if (fault_signal_pending(fault, regs)) {
+ /*
+ * Quick path to respond to signals. The core mm code
+ * has unlocked the mm for us if we get here.
+ */
if (!user_mode(regs))
no_context(regs, error_code, address, SIGBUS,
BUS_ADRERR);
--
2.29.2
next prev parent reply other threads:[~2021-02-10 2:38 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-10 2:33 [PATCH v2 00/14] x86/fault: #PF improvements, mostly related to USER bit Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 01/14] x86/fault: Fix AMD erratum #91 errata fixup for user code Andy Lutomirski
2021-02-10 7:34 ` Christoph Hellwig
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 02/14] x86/fault: Skip the AMD erratum #91 workaround on unaffected CPUs Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 03/14] x86/fault: Fold mm_fault_error() into do_user_addr_fault() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 04/14] x86/fault/32: Move is_f00f_bug() to do_kern_addr_fault() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` Andy Lutomirski [this message]
2021-02-10 17:45 ` [tip: x86/mm] x86/fault: Document the locking in the fault_signal_pending() path tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 06/14] x86/fault: Correct a few user vs kernel checks wrt WRUSS Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 07/14] x86/fault: Improve kernel-executing-user-memory handling Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 08/14] x86/fault: Skip erratum #93 workaround on new CPUs Andy Lutomirski
2021-02-10 6:06 ` Andy Lutomirski
2021-02-10 13:29 ` Borislav Petkov
2021-02-10 16:09 ` Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 09/14] x86/fault: Split the OOPS code out from no_context() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 10/14] x86/fault: Bypass no_context() for implicit kernel faults from usermode Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 11/14] x86/fault: Rename no_context() to kernelmode_fixup_or_oops() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 12/14] x86/fault: Don't look for extable entries for SMEP violations Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 13/14] x86/fault: Don't run fixups for SMAP violations Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 14/14] x86/fault, x86/efi: Fix and rename efi_recover_from_page_fault() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] x86/{fault,efi}: " tip-bot2 for Andy Lutomirski
2021-02-11 8:38 ` [PATCH v2 14/14] x86/fault, x86/efi: " Ard Biesheuvel
2021-02-10 13:57 ` [RFC][PATCH] kprobes: Remove kprobe::fault_handler Peter Zijlstra
2021-02-10 19:09 ` Christoph Hellwig
2021-02-10 19:47 ` Alexei Starovoitov
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