| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <tip-0ed32f1aa66ee758e6c8164f549f7ff9d399a20e@git.kernel.org>
Date: Thu, 22 Nov 2018 02:09:54 -0800
From: tip-bot for Andy Lutomirski <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: hpa@...or.com, mingo@...nel.org, torvalds@...ux-foundation.org,
dave.hansen@...ux.intel.com, bp@...en8.de, tglx@...utronix.de,
linux-kernel@...r.kernel.org, peterz@...radead.org,
luto@...nel.org, yu-cheng.yu@...el.com, riel@...riel.com
Subject: [tip:x86/mm] x86/fault: Remove sw_error_code
Commit-ID: 0ed32f1aa66ee758e6c8164f549f7ff9d399a20e
Gitweb: https://git.kernel.org/tip/0ed32f1aa66ee758e6c8164f549f7ff9d399a20e
Author: Andy Lutomirski <luto@...nel.org>
AuthorDate: Wed, 21 Nov 2018 15:11:22 -0800
Committer: Ingo Molnar <mingo@...nel.org>
CommitDate: Thu, 22 Nov 2018 09:22:59 +0100
x86/fault: Remove sw_error_code
All of the fault handling code now corrently checks user_mode(regs)
as needed, and nothing depends on the X86_PF_USER bit being munged.
Get rid of the sw_error code and use hw_error_code everywhere.
Signed-off-by: Andy Lutomirski <luto@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rik van Riel <riel@...riel.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@...el.com>
Link: http://lkml.kernel.org/r/078f5b8ae6e8c79ff8ee7345b5c476c45003e5ac.1542841400.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/mm/fault.c | 50 +++++++++++---------------------------------------
1 file changed, 11 insertions(+), 39 deletions(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index b898a38093a3..82881bc5feef 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1217,7 +1217,6 @@ void do_user_addr_fault(struct pt_regs *regs,
unsigned long hw_error_code,
unsigned long address)
{
- unsigned long sw_error_code;
struct vm_area_struct *vma;
struct task_struct *tsk;
struct mm_struct *mm;
@@ -1262,13 +1261,6 @@ void do_user_addr_fault(struct pt_regs *regs,
return;
}
- /*
- * hw_error_code is literally the "page fault error code" passed to
- * the kernel directly from the hardware. But, we will shortly be
- * modifying it in software, so give it a new name.
- */
- sw_error_code = hw_error_code;
-
/*
* It's safe to allow irq's after cr2 has been saved and the
* vmalloc fault has been handled.
@@ -1278,26 +1270,6 @@ void do_user_addr_fault(struct pt_regs *regs,
*/
if (user_mode(regs)) {
local_irq_enable();
- /*
- * Up to this point, X86_PF_USER set in hw_error_code
- * indicated a user-mode access. But, after this,
- * X86_PF_USER in sw_error_code will indicate either
- * that, *or* an implicit kernel(supervisor)-mode access
- * which originated from user mode.
- */
- if (!(hw_error_code & X86_PF_USER)) {
- /*
- * The CPU was in user mode, but the CPU says
- * the fault was not a user-mode access.
- * Must be an implicit kernel-mode access,
- * which we do not expect to happen in the
- * user address space.
- */
- pr_warn_once("kernel-mode error from user-mode: %lx\n",
- hw_error_code);
-
- sw_error_code |= X86_PF_USER;
- }
flags |= FAULT_FLAG_USER;
} else {
if (regs->flags & X86_EFLAGS_IF)
@@ -1306,9 +1278,9 @@ void do_user_addr_fault(struct pt_regs *regs,
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
- if (sw_error_code & X86_PF_WRITE)
+ if (hw_error_code & X86_PF_WRITE)
flags |= FAULT_FLAG_WRITE;
- if (sw_error_code & X86_PF_INSTR)
+ if (hw_error_code & X86_PF_INSTR)
flags |= FAULT_FLAG_INSTRUCTION;
#ifdef CONFIG_X86_64
@@ -1321,7 +1293,7 @@ void do_user_addr_fault(struct pt_regs *regs,
* The vsyscall page does not have a "real" VMA, so do this
* emulation before we go searching for VMAs.
*/
- if ((sw_error_code & X86_PF_INSTR) && is_vsyscall_vaddr(address)) {
+ if ((hw_error_code & X86_PF_INSTR) && is_vsyscall_vaddr(address)) {
if (emulate_vsyscall(regs, address))
return;
}
@@ -1345,7 +1317,7 @@ void do_user_addr_fault(struct pt_regs *regs,
* Fault from code in kernel from
* which we do not expect faults.
*/
- bad_area_nosemaphore(regs, sw_error_code, address);
+ bad_area_nosemaphore(regs, hw_error_code, address);
return;
}
retry:
@@ -1361,17 +1333,17 @@ retry:
vma = find_vma(mm, address);
if (unlikely(!vma)) {
- bad_area(regs, sw_error_code, address);
+ bad_area(regs, hw_error_code, address);
return;
}
if (likely(vma->vm_start <= address))
goto good_area;
if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) {
- bad_area(regs, sw_error_code, address);
+ bad_area(regs, hw_error_code, address);
return;
}
if (unlikely(expand_stack(vma, address))) {
- bad_area(regs, sw_error_code, address);
+ bad_area(regs, hw_error_code, address);
return;
}
@@ -1380,8 +1352,8 @@ retry:
* we can handle it..
*/
good_area:
- if (unlikely(access_error(sw_error_code, vma))) {
- bad_area_access_error(regs, sw_error_code, address, vma);
+ if (unlikely(access_error(hw_error_code, vma))) {
+ bad_area_access_error(regs, hw_error_code, address, vma);
return;
}
@@ -1420,13 +1392,13 @@ good_area:
return;
/* Not returning to user mode? Handle exceptions or die: */
- no_context(regs, sw_error_code, address, SIGBUS, BUS_ADRERR);
+ no_context(regs, hw_error_code, address, SIGBUS, BUS_ADRERR);
return;
}
up_read(&mm->mmap_sem);
if (unlikely(fault & VM_FAULT_ERROR)) {
- mm_fault_error(regs, sw_error_code, address, fault);
+ mm_fault_error(regs, hw_error_code, address, fault);
return;
}
Powered by blists - more mailing lists