linux-kernel - [PATCH mm-unstable v2 14/16] mm: xtensa: Introduce arch_mmap

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]

Message-ID: <20241211232754.1583023-15-kaleshsingh@google.com>
Date: Wed, 11 Dec 2024 15:27:52 -0800
From: Kalesh Singh <kaleshsingh@...gle.com>
To: akpm@...ux-foundation.org, vbabka@...e.cz, yang@...amperecomputing.com, 
	riel@...riel.com, david@...hat.com, minchan@...nel.org, jyescas@...gle.com
Cc: linux@...linux.org.uk, tsbogend@...ha.franken.de, 
	James.Bottomley@...senPartnership.com, ysato@...rs.sourceforge.jp, 
	dalias@...c.org, glaubitz@...sik.fu-berlin.de, davem@...emloft.net, 
	andreas@...sler.com, tglx@...utronix.de, bp@...en8.de, 
	dave.hansen@...ux.intel.com, x86@...nel.org, chris@...kel.net, 
	jcmvbkbc@...il.com, bhelgaas@...gle.com, jason.andryuk@....com, 
	leitao@...ian.org, linux-alpha@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-snps-arc@...ts.infradead.org, linux-arm-kernel@...ts.infradead.org, 
	linux-csky@...r.kernel.org, loongarch@...ts.linux.dev, 
	linux-mips@...r.kernel.org, linux-parisc@...r.kernel.org, 
	linuxppc-dev@...ts.ozlabs.org, linux-s390@...r.kernel.org, 
	linux-sh@...r.kernel.org, sparclinux@...r.kernel.org, linux-mm@...ck.org, 
	kernel-team@...roid.com, android-mm@...gle.com, 
	Kalesh Singh <kaleshsingh@...gle.com>
Subject: [PATCH mm-unstable v2 14/16] mm: xtensa: Introduce arch_mmap_hint()

Introduce xtensa arch_mmap_hint() and define HAVE_ARCH_MMAP_HINT.

If a sufficiently sized hole doesn't exist at the hint address,
fallback to searching the entire valid VA space instead of only
the VA space above the hint address.

Signed-off-by: Kalesh Singh <kaleshsingh@...gle.com>
---

Changes in v2:
  - MAP_FIXED case is also handled in arch_mmap_hint() since this is just a
    special case of the hint addr being "enforced", per Yang Shi.
  - Consolidate error handling in arch_mmap_hint().

 arch/xtensa/kernel/syscall.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index dc54f854c2f5..6bbe10c2a633 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -54,12 +54,12 @@ asmlinkage long xtensa_fadvise64_64(int fd, int advice,
 }
 
 #ifdef CONFIG_MMU
-unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
-		unsigned long len, unsigned long pgoff, unsigned long flags,
-		vm_flags_t vm_flags)
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+			     unsigned long len, unsigned long pgoff,
+			     unsigned long flags)
 {
-	struct vm_area_struct *vmm;
-	struct vma_iterator vmi;
+	if (len > TASK_SIZE)
+		return -ENOMEM;
 
 	if (flags & MAP_FIXED) {
 		/* We do not accept a shared mapping if it would violate
@@ -71,16 +71,27 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 		return addr;
 	}
 
-	if (len > TASK_SIZE)
-		return -ENOMEM;
-	if (!addr)
-		addr = TASK_UNMAPPED_BASE;
-
 	if (flags & MAP_SHARED)
 		addr = COLOUR_ALIGN(addr, pgoff);
 	else
 		addr = PAGE_ALIGN(addr);
 
+	return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
+		unsigned long len, unsigned long pgoff, unsigned long flags,
+		vm_flags_t vm_flags)
+{
+	struct vm_area_struct *vmm;
+	struct vma_iterator vmi;
+
+	addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+	if (addr)
+		return addr;
+
+	addr = TASK_UNMAPPED_BASE;
+
 	vma_iter_init(&vmi, current->mm, addr);
 	for_each_vma(vmi, vmm) {
 		/* At this point:  (addr < vmm->vm_end). */
-- 
2.47.0.338.g60cca15819-goog