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AJvYcCVnvMUmLOF03Xx70snIDsHpjK6vZ8gVPiHPfEhBSjOBAf1utXBjL4DpAWPJfFU7yu00NvLQmLcZNg==@vger.kernel.org X-Gm-Message-State: AOJu0Yxa2ck4iGs/n7H76y/xj/Ur70/w23csNgCcWE+W2VErTss1sI+N gvLHSn9l2PhtlJgMwpjFGeVC1ETeFPRuMr14JWfY3llf3KIDSv1imj89Ip4C74xOc4YydQh8EzT 5En90dlNY8JBX2WvSubnQdQ== X-Google-Smtp-Source: AGHT+IHwoWCnSZAFhgfRGzh0vJKMetndx4pRL/iGA/i3q5lPp5GtpRRmcU9xCr75DNYXJvBdH8Wl1Hh5YkFK8klCiw== X-Received: from pge13.prod.google.com ([2002:a05:6a02:2d0d:b0:801:9432:2d6d]) (user=kaleshsingh job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:cf83:b0:1d9:18af:d150 with SMTP id adf61e73a8af0-1e1ceafb16amr1741157637.21.1733959681795; Wed, 11 Dec 2024 15:28:01 -0800 (PST) Date: Wed, 11 Dec 2024 15:27:40 -0800 In-Reply-To: <20241211232754.1583023-1-kaleshsingh@google.com> Precedence: bulk X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241211232754.1583023-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.47.0.338.g60cca15819-goog Message-ID: <20241211232754.1583023-3-kaleshsingh@google.com> Subject: [PATCH mm-unstable v2 02/16] mm: x86: Introduce arch_mmap_hint() From: Kalesh Singh To: akpm@linux-foundation.org, vbabka@suse.cz, yang@os.amperecomputing.com, riel@surriel.com, david@redhat.com, minchan@kernel.org, jyescas@google.com Cc: linux@armlinux.org.uk, tsbogend@alpha.franken.de, James.Bottomley@HansenPartnership.com, ysato@users.sourceforge.jp, dalias@libc.org, glaubitz@physik.fu-berlin.de, davem@davemloft.net, andreas@gaisler.com, tglx@linutronix.de, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, chris@zankel.net, jcmvbkbc@gmail.com, bhelgaas@google.com, jason.andryuk@amd.com, leitao@debian.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, kernel-team@android.com, android-mm@google.com, Kalesh Singh Introduce x86 arch_mmap_hint() and define HAVE_ARCH_MMAP_HINT. This is a preparatory patch, no functional change is introduced. Fallback to generic_mmap_hint() if an architecture doesn't provide HAVE_ARCH_MMAP_HINT. Signed-off-by: Kalesh Singh --- 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 most of the error handling in arch_mmap_hint(). - Fallback to generic_mmap_hint() if arch_mmap_hint() is not provided. arch/x86/include/asm/pgtable_64.h | 1 + arch/x86/kernel/sys_x86_64.c | 64 +++++++++++++++---------------- include/linux/sched/mm.h | 5 +++ mm/mmap.c | 9 +++++ 4 files changed, 45 insertions(+), 34 deletions(-) diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index d1426b64c1b9..4472fd0040c3 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -245,6 +245,7 @@ extern void cleanup_highmap(void); #define HAVE_ARCH_UNMAPPED_AREA #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN +#define HAVE_ARCH_MMAP_HINT #define PAGE_AGP PAGE_KERNEL_NOCACHE #define HAVE_PAGE_AGP 1 diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index 776ae6fa7f2d..008c6d19bd02 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -123,31 +123,44 @@ static inline unsigned long stack_guard_placement(vm_flags_t vm_flags) return 0; } +unsigned long arch_mmap_hint(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags) +{ + unsigned long begin, end; + + find_start_end(addr, flags, &begin, &end); + + /* requested length too big for entire address space */ + if (len > end || len > TASK_SIZE) + return -ENOMEM; + + /* No address checking. See comment at mmap_address_hint_valid() */ + if (flags & MAP_FIXED) + return addr; + + addr = PAGE_ALIGN(addr); + + /* Fallback to VA space search? */ + if (!mmap_address_hint_valid(addr, len)) + return 0; + + 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 mm_struct *mm = current->mm; - struct vm_area_struct *vma; struct vm_unmapped_area_info info = {}; unsigned long begin, end; - if (flags & MAP_FIXED) + addr = arch_mmap_hint(filp, addr, len, pgoff, flags); + if (addr) return addr; find_start_end(addr, flags, &begin, &end); - if (len > end) - return -ENOMEM; - - if (addr) { - addr = PAGE_ALIGN(addr); - vma = find_vma(mm, addr); - if (end - len >= addr && - (!vma || addr + len <= vm_start_gap(vma))) - return addr; - } - info.length = len; info.low_limit = begin; info.high_limit = end; @@ -168,34 +181,17 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr0, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags) { - struct vm_area_struct *vma; - struct mm_struct *mm = current->mm; unsigned long addr = addr0; struct vm_unmapped_area_info info = {}; - /* requested length too big for entire address space */ - if (len > TASK_SIZE) - return -ENOMEM; - - /* No address checking. See comment at mmap_address_hint_valid() */ - if (flags & MAP_FIXED) - return addr; - /* for MAP_32BIT mappings we force the legacy mmap base */ if (!in_32bit_syscall() && (flags & MAP_32BIT)) goto bottomup; /* requesting a specific address */ - if (addr) { - addr &= PAGE_MASK; - if (!mmap_address_hint_valid(addr, len)) - goto get_unmapped_area; - - vma = find_vma(mm, addr); - if (!vma || addr + len <= vm_start_gap(vma)) - return addr; - } -get_unmapped_area: + addr = arch_mmap_hint(filp, addr, len, pgoff, flags); + if (addr) + return addr; info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index edeec19d1708..f4143703f234 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -205,6 +205,11 @@ unsigned long generic_mmap_hint(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags); +/* See generic_mmap_hint() */ +unsigned long arch_mmap_hint(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags); + unsigned long generic_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, diff --git a/mm/mmap.c b/mm/mmap.c index 382b4eac5406..76dd6acdf051 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -705,6 +705,15 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, } #endif +#ifndef HAVE_ARCH_MMAP_HINT +unsigned long arch_mmap_hint(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags) +{ + return generic_mmap_hint(filp, addr, len, pgoff, flags); +} +#endif + /* * This mmap-allocator allocates new areas top-down from below the * stack's low limit (the base):