linux-kernel - [PATCH 23/25] mm/unicore32: Use mm_fault

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 15 Jun 2020 18:23:21 -0400
From:   Peter Xu <peterx@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     Peter Xu <peterx@...hat.com>,
        Gerald Schaefer <gerald.schaefer@...ibm.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Guan Xuetao <gxt@....edu.cn>
Subject: [PATCH 23/25] mm/unicore32: Use mm_fault_accounting()

Use the new mm_fault_accounting() helper for page fault accounting.

Avoid doing page fault accounting multiple times if the page fault is retried.
Also, the perf events for page faults will be accounted too when the config has
CONFIG_PERF_EVENTS defined.

CC: Guan Xuetao <gxt@....edu.cn>
Signed-off-by: Peter Xu <peterx@...hat.com>
---
 arch/unicore32/mm/fault.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
index 3022104aa613..240b38e81ed6 100644
--- a/arch/unicore32/mm/fault.c
+++ b/arch/unicore32/mm/fault.c
@@ -201,7 +201,7 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	struct task_struct *tsk;
 	struct mm_struct *mm;
 	int sig, code;
-	vm_fault_t fault;
+	vm_fault_t fault, major = 0;
 	unsigned int flags = FAULT_FLAG_DEFAULT;
 
 	tsk = current;
@@ -245,6 +245,7 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	}
 
 	fault = __do_pf(mm, addr, fsr, flags, tsk);
+	major |= fault & VM_FAULT_MAJOR;
 
 	/* If we need to retry but a fatal signal is pending, handle the
 	 * signal first. We do not need to release the mmap_sem because
@@ -254,10 +255,6 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 		return 0;
 
 	if (!(fault & VM_FAULT_ERROR) && (flags & FAULT_FLAG_ALLOW_RETRY)) {
-		if (fault & VM_FAULT_MAJOR)
-			tsk->maj_flt++;
-		else
-			tsk->min_flt++;
 		if (fault & VM_FAULT_RETRY) {
 			flags |= FAULT_FLAG_TRIED;
 			goto retry;
@@ -267,11 +264,13 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	up_read(&mm->mmap_sem);
 
 	/*
-	 * Handle the "normal" case first - VM_FAULT_MAJOR
+	 * Handle the "normal" case first
 	 */
-	if (likely(!(fault &
-	       (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS))))
+	if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
+			      VM_FAULT_BADACCESS)))) {
+		mm_fault_accounting(tsk, regs, addr, major);
 		return 0;
+	}
 
 	/*
 	 * If we are in kernel mode at this point, we
-- 
2.26.2