linux-kernel - [PATCH v2 1/4] mm/vmalloc: invoke classify_va_fit_type() in adjust_va_to_fit

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 for Android: free password hash cracker in your pocket

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

Date:   Tue,  7 Jun 2022 18:59:55 +0800
From:   Baoquan He <bhe@...hat.com>
To:     akpm@...ux-foundation.org, urezki@...il.com
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        hch@...radead.org, Baoquan He <bhe@...hat.com>
Subject: [PATCH v2 1/4] mm/vmalloc: invoke classify_va_fit_type() in adjust_va_to_fit_type()

In function adjust_va_to_fit_type(), it checks all values of passed
in fit type, including NOTHING_FIT in the else branch. However, the
check of NOTHING_FIT has been done inside adjust_va_to_fit_type() and
before it's called in all call sites.

In fact, both of these two functions are coupled tightly, since
classify_va_fit_type() is doing the preparation work for
adjust_va_to_fit_type(). So putting invocation of classify_va_fit_type()
inside adjust_va_to_fit_type() can simplify code logic and the redundant
check of NOTHING_FIT issue will go away.

Suggested-by: Uladzislau Rezki (Sony) <urezki@...il.com>
Signed-off-by: Baoquan He <bhe@...hat.com>
---
 mm/vmalloc.c | 23 ++++++-----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 07db42455dd4..f9d45aa90b7c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1335,10 +1335,10 @@ classify_va_fit_type(struct vmap_area *va,
 
 static __always_inline int
 adjust_va_to_fit_type(struct vmap_area *va,
-	unsigned long nva_start_addr, unsigned long size,
-	enum fit_type type)
+	unsigned long nva_start_addr, unsigned long size)
 {
 	struct vmap_area *lva = NULL;
+	enum fit_type type = classify_va_fit_type(va, nva_start_addr, size);
 
 	if (type == FL_FIT_TYPE) {
 		/*
@@ -1444,7 +1444,6 @@ __alloc_vmap_area(unsigned long size, unsigned long align,
 	bool adjust_search_size = true;
 	unsigned long nva_start_addr;
 	struct vmap_area *va;
-	enum fit_type type;
 	int ret;
 
 	/*
@@ -1472,14 +1471,9 @@ __alloc_vmap_area(unsigned long size, unsigned long align,
 	if (nva_start_addr + size > vend)
 		return vend;
 
-	/* Classify what we have found. */
-	type = classify_va_fit_type(va, nva_start_addr, size);
-	if (WARN_ON_ONCE(type == NOTHING_FIT))
-		return vend;
-
 	/* Update the free vmap_area. */
-	ret = adjust_va_to_fit_type(va, nva_start_addr, size, type);
-	if (ret)
+	ret = adjust_va_to_fit_type(va, nva_start_addr, size);
+	if (WARN_ON_ONCE(ret))
 		return vend;
 
 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
@@ -3735,7 +3729,6 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 	int area, area2, last_area, term_area;
 	unsigned long base, start, size, end, last_end, orig_start, orig_end;
 	bool purged = false;
-	enum fit_type type;
 
 	/* verify parameters and allocate data structures */
 	BUG_ON(offset_in_page(align) || !is_power_of_2(align));
@@ -3846,15 +3839,11 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 			/* It is a BUG(), but trigger recovery instead. */
 			goto recovery;
 
-		type = classify_va_fit_type(va, start, size);
-		if (WARN_ON_ONCE(type == NOTHING_FIT))
+		ret = adjust_va_to_fit_type(va, start, size);
+		if (WARN_ON_ONCE(unlikely(ret)))
 			/* It is a BUG(), but trigger recovery instead. */
 			goto recovery;
 
-		ret = adjust_va_to_fit_type(va, start, size, type);
-		if (unlikely(ret))
-			goto recovery;
-
 		/* Allocated area. */
 		va = vas[area];
 		va->va_start = start;
-- 
2.34.1