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 09/11] x86/fault: Rename no_context() to kernelmode_fixup_or_oops()
Date: Sun, 31 Jan 2021 09:24:40 -0800 [thread overview]
Message-ID: <5b0ad34afeeee15032393367b0945a5032903162.1612113550.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1612113550.git.luto@kernel.org>
The name no_context() has never been very clear. It's only called for
faults from kernel mode, so rename it and change the no-longer-useful
user_mode(regs) check to a WARN_ON_ONCE.
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 | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 177b612c7f33..04cc98ec2423 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -693,17 +693,10 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code,
}
static noinline void
-no_context(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, int signal, int si_code)
+kernelmode_fixup_or_oops(struct pt_regs *regs, unsigned long error_code,
+ unsigned long address, int signal, int si_code)
{
- if (user_mode(regs)) {
- /*
- * This is an implicit supervisor-mode access from user
- * mode. Bypass all the kernel-mode recovery code and just
- * OOPS.
- */
- goto oops;
- }
+ WARN_ON_ONCE(user_mode(regs));
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs, X86_TRAP_PF, error_code, address)) {
@@ -743,7 +736,6 @@ no_context(struct pt_regs *regs, unsigned long error_code,
if (is_prefetch(regs, error_code, address))
return;
-oops:
page_fault_oops(regs, error_code, address);
}
@@ -790,7 +782,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
struct task_struct *tsk = current;
if (!user_mode(regs)) {
- no_context(regs, error_code, address, pkey, si_code);
+ kernelmode_fixup_or_oops(regs, error_code, address, pkey, si_code);
return;
}
@@ -922,7 +914,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
{
/* Kernel mode? Handle exceptions or die: */
if (!user_mode(regs)) {
- no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
+ kernelmode_fixup_or_oops(regs, error_code, address, SIGBUS, BUS_ADRERR);
return;
}
@@ -1382,8 +1374,8 @@ void do_user_addr_fault(struct pt_regs *regs,
* has unlocked the mm for us if we get here.
*/
if (!user_mode(regs))
- no_context(regs, error_code, address, SIGBUS,
- BUS_ADRERR);
+ kernelmode_fixup_or_oops(regs, error_code, address,
+ SIGBUS, BUS_ADRERR);
return;
}
@@ -1403,15 +1395,15 @@ void do_user_addr_fault(struct pt_regs *regs,
return;
if (fatal_signal_pending(current) && !user_mode(regs)) {
- no_context(regs, error_code, address, 0, 0);
+ kernelmode_fixup_or_oops(regs, error_code, address, 0, 0);
return;
}
if (fault & VM_FAULT_OOM) {
/* Kernel mode? Handle exceptions or die: */
if (!user_mode(regs)) {
- no_context(regs, error_code, address,
- SIGSEGV, SEGV_MAPERR);
+ kernelmode_fixup_or_oops(regs, error_code, address,
+ SIGSEGV, SEGV_MAPERR);
return;
}
--
2.29.2
next prev parent reply other threads:[~2021-01-31 20:00 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-31 17:24 [PATCH 00/11] x86/fault: Cleanups and robustifications Andy Lutomirski
2021-01-31 17:24 ` [PATCH 01/11] x86/fault: Fix AMD erratum #91 errata fixup for user code Andy Lutomirski
2021-02-01 9:05 ` Christoph Hellwig
2021-02-01 20:31 ` Borislav Petkov
2021-01-31 17:24 ` [PATCH 02/11] x86/fault: Fold mm_fault_error() into do_user_addr_fault() Andy Lutomirski
2021-01-31 17:24 ` [PATCH 03/11] x86/fault/32: Move is_f00f_bug() do do_kern_addr_fault() Andy Lutomirski
2021-02-03 14:44 ` Borislav Petkov
2021-01-31 17:24 ` [PATCH 04/11] x86/fault: Document the locking in the fault_signal_pending() path Andy Lutomirski
2021-01-31 17:24 ` [PATCH 05/11] x86/fault: Correct a few user vs kernel checks wrt WRUSS Andy Lutomirski
2021-02-03 15:48 ` Borislav Petkov
2021-01-31 17:24 ` [PATCH 06/11] x86/fault: Improve kernel-executing-user-memory handling Andy Lutomirski
2021-02-01 9:08 ` Christoph Hellwig
2021-02-02 1:00 ` Andy Lutomirski
2021-02-03 16:01 ` Borislav Petkov
2021-02-03 16:23 ` Borislav Petkov
2021-01-31 17:24 ` [PATCH 07/11] x86/fault: Split the OOPS code out from no_context() Andy Lutomirski
2021-02-03 18:56 ` Borislav Petkov
2021-02-03 19:29 ` Andy Lutomirski
2021-02-03 19:46 ` Borislav Petkov
2021-02-09 20:09 ` Andy Lutomirski
2021-01-31 17:24 ` [PATCH 08/11] x86/fault: Bypass no_context() for implicit kernel faults from usermode Andy Lutomirski
2021-01-31 17:24 ` Andy Lutomirski [this message]
2021-02-01 9:14 ` [PATCH 09/11] x86/fault: Rename no_context() to kernelmode_fixup_or_oops() Christoph Hellwig
2021-02-02 1:01 ` Andy Lutomirski
2021-02-03 19:39 ` Borislav Petkov
2021-02-03 19:53 ` Andy Lutomirski
2021-02-03 20:07 ` Borislav Petkov
2021-02-03 20:14 ` Andy Lutomirski
2021-02-03 20:25 ` Borislav Petkov
2021-01-31 17:24 ` [PATCH 10/11] x86/fault: Don't run fixups for SMAP violations Andy Lutomirski
2021-02-03 19:50 ` Borislav Petkov
2021-01-31 17:24 ` [PATCH 11/11] x86/fault: Don't look for extable entries for SMEP violations Andy Lutomirski
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