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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/arm/mm/mmap.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mm/mmap.c')
-rw-r--r--arch/arm/mm/mmap.c167
1 files changed, 167 insertions, 0 deletions
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
new file mode 100644
index 0000000000..a0f8a0ca07
--- /dev/null
+++ b/arch/arm/mm/mmap.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/arm/mm/mmap.c
+ */
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/shm.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
+#include <linux/io.h>
+#include <linux/personality.h>
+#include <linux/random.h>
+#include <asm/cachetype.h>
+
+#define COLOUR_ALIGN(addr,pgoff) \
+ ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
+ (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+
+/*
+ * We need to ensure that shared mappings are correctly aligned to
+ * avoid aliasing issues with VIPT caches. We need to ensure that
+ * a specific page of an object is always mapped at a multiple of
+ * SHMLBA bytes.
+ *
+ * We unconditionally provide this function for all cases, however
+ * in the VIVT case, we optimise out the alignment rules.
+ */
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ int do_align = 0;
+ int aliasing = cache_is_vipt_aliasing();
+ struct vm_unmapped_area_info info;
+
+ /*
+ * We only need to do colour alignment if either the I or D
+ * caches alias.
+ */
+ if (aliasing)
+ do_align = filp || (flags & MAP_SHARED);
+
+ /*
+ * We enforce the MAP_FIXED case.
+ */
+ if (flags & MAP_FIXED) {
+ if (aliasing && flags & MAP_SHARED &&
+ (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
+ return -EINVAL;
+ return addr;
+ }
+
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (addr) {
+ if (do_align)
+ addr = COLOUR_ALIGN(addr, pgoff);
+ else
+ addr = PAGE_ALIGN(addr);
+
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vm_start_gap(vma)))
+ return addr;
+ }
+
+ info.flags = 0;
+ info.length = len;
+ info.low_limit = mm->mmap_base;
+ info.high_limit = TASK_SIZE;
+ info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
+ info.align_offset = pgoff << PAGE_SHIFT;
+ return vm_unmapped_area(&info);
+}
+
+unsigned long
+arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+ const unsigned long len, const unsigned long pgoff,
+ const unsigned long flags)
+{
+ struct vm_area_struct *vma;
+ struct mm_struct *mm = current->mm;
+ unsigned long addr = addr0;
+ int do_align = 0;
+ int aliasing = cache_is_vipt_aliasing();
+ struct vm_unmapped_area_info info;
+
+ /*
+ * We only need to do colour alignment if either the I or D
+ * caches alias.
+ */
+ if (aliasing)
+ do_align = filp || (flags & MAP_SHARED);
+
+ /* requested length too big for entire address space */
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (flags & MAP_FIXED) {
+ if (aliasing && flags & MAP_SHARED &&
+ (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
+ return -EINVAL;
+ return addr;
+ }
+
+ /* requesting a specific address */
+ if (addr) {
+ if (do_align)
+ addr = COLOUR_ALIGN(addr, pgoff);
+ else
+ addr = PAGE_ALIGN(addr);
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vm_start_gap(vma)))
+ return addr;
+ }
+
+ info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+ info.length = len;
+ info.low_limit = FIRST_USER_ADDRESS;
+ info.high_limit = mm->mmap_base;
+ info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
+ info.align_offset = pgoff << PAGE_SHIFT;
+ addr = vm_unmapped_area(&info);
+
+ /*
+ * A failed mmap() very likely causes application failure,
+ * so fall back to the bottom-up function here. This scenario
+ * can happen with large stack limits and large mmap()
+ * allocations.
+ */
+ if (addr & ~PAGE_MASK) {
+ VM_BUG_ON(addr != -ENOMEM);
+ info.flags = 0;
+ info.low_limit = mm->mmap_base;
+ info.high_limit = TASK_SIZE;
+ addr = vm_unmapped_area(&info);
+ }
+
+ return addr;
+}
+
+/*
+ * You really shouldn't be using read() or write() on /dev/mem. This
+ * might go away in the future.
+ */
+int valid_phys_addr_range(phys_addr_t addr, size_t size)
+{
+ if (addr < PHYS_OFFSET)
+ return 0;
+ if (addr + size > __pa(high_memory - 1) + 1)
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Do not allow /dev/mem mappings beyond the supported physical range.
+ */
+int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
+{
+ return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT));
+}