[kernel] r18475 - in dists/trunk/linux-2.6/debian: . patches/bugfix/arm
Arnaud Patard
rtp-guest at alioth.debian.org
Sun Jan 8 10:48:17 UTC 2012
Author: rtp-guest
Date: Sun Jan 8 10:48:16 2012
New Revision: 18475
Log:
Backport topdown mmap support on arm (http://lists.debian.org/debian-arm/2011/12/msg00136.html)
Added:
dists/trunk/linux-2.6/debian/patches/bugfix/arm/ARM-topdown-mmap.patch
Modified:
dists/trunk/linux-2.6/debian/changelog
Modified: dists/trunk/linux-2.6/debian/changelog
==============================================================================
--- dists/trunk/linux-2.6/debian/changelog Sun Jan 8 10:47:12 2012 (r18474)
+++ dists/trunk/linux-2.6/debian/changelog Sun Jan 8 10:48:16 2012 (r18475)
@@ -19,6 +19,7 @@
[ Arnaud Patard ]
* disable tomoyo and apparmor to allow kernel image to fit into flash.
* add back ixp4xx gpiolib patch
+ * backport topdown mmap support from rmk's tree
-- Ben Hutchings <ben at decadent.org.uk> Mon, 02 Jan 2012 02:55:28 +0000
Added: dists/trunk/linux-2.6/debian/patches/bugfix/arm/ARM-topdown-mmap.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/trunk/linux-2.6/debian/patches/bugfix/arm/ARM-topdown-mmap.patch Sun Jan 8 10:48:16 2012 (r18475)
@@ -0,0 +1,258 @@
+http://ftp.arm.linux.org.uk/git/gitweb.cgi?p=linux-2.6-arm.git;a=commit;h=7dbaa466780a754154531b44c2086f6618cee3a8
+
+From 7dbaa466780a754154531b44c2086f6618cee3a8 Mon Sep 17 00:00:00 2001
+From: Rob Herring <rob.herring at calxeda.com>
+Date: Tue, 22 Nov 2011 04:01:07 +0100
+Subject: [PATCH] ARM: 7169/1: topdown mmap support
+
+Similar to other architectures, this adds topdown mmap support in user
+process address space allocation policy. This allows mmap sizes greater
+than 2GB. This support is largely copied from MIPS and the generic
+implementations.
+
+The address space randomization is moved into arch_pick_mmap_layout.
+
+Tested on V-Express with ubuntu and a mmap test from here:
+https://bugs.launchpad.net/bugs/861296
+
+Signed-off-by: Rob Herring <rob.herring at calxeda.com>
+Acked-by: Nicolas Pitre <nico at linaro.org>
+Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
+---
+ arch/arm/include/asm/pgtable.h | 1 +
+ arch/arm/include/asm/processor.h | 2 +
+ arch/arm/mm/mmap.c | 173 ++++++++++++++++++++++++++++++++++++-
+ 3 files changed, 171 insertions(+), 5 deletions(-)
+
+diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
+index 9451dce..2f659e2 100644
+--- a/arch/arm/include/asm/pgtable.h
++++ b/arch/arm/include/asm/pgtable.h
+@@ -336,6 +336,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+ * We provide our own arch_get_unmapped_area to cope with VIPT caches.
+ */
+ #define HAVE_ARCH_UNMAPPED_AREA
++#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+
+ /*
+ * remap a physical page `pfn' of size `size' with page protection `prot'
+diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
+index b2d9df5..ce280b8 100644
+--- a/arch/arm/include/asm/processor.h
++++ b/arch/arm/include/asm/processor.h
+@@ -123,6 +123,8 @@ static inline void prefetch(const void *ptr)
+
+ #endif
+
++#define HAVE_ARCH_PICK_MMAP_LAYOUT
++
+ #endif
+
+ #endif /* __ASM_ARM_PROCESSOR_H */
+diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
+index 44b628e..ce8cb19 100644
+--- a/arch/arm/mm/mmap.c
++++ b/arch/arm/mm/mmap.c
+@@ -11,10 +11,49 @@
+ #include <linux/random.h>
+ #include <asm/cachetype.h>
+
++static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
++ unsigned long pgoff)
++{
++ unsigned long base = addr & ~(SHMLBA-1);
++ unsigned long off = (pgoff << PAGE_SHIFT) & (SHMLBA-1);
++
++ if (base + off <= addr)
++ return base + off;
++
++ return base - off;
++}
++
+ #define COLOUR_ALIGN(addr,pgoff) \
+ ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
+ (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+
++/* gap between mmap and stack */
++#define MIN_GAP (128*1024*1024UL)
++#define MAX_GAP ((TASK_SIZE)/6*5)
++
++static int mmap_is_legacy(void)
++{
++ if (current->personality & ADDR_COMPAT_LAYOUT)
++ return 1;
++
++ if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
++ return 1;
++
++ return sysctl_legacy_va_layout;
++}
++
++static unsigned long mmap_base(unsigned long rnd)
++{
++ unsigned long gap = rlimit(RLIMIT_STACK);
++
++ if (gap < MIN_GAP)
++ gap = MIN_GAP;
++ else if (gap > MAX_GAP)
++ gap = MAX_GAP;
++
++ return PAGE_ALIGN(TASK_SIZE - gap - rnd);
++}
++
+ /*
+ * We need to ensure that shared mappings are correctly aligned to
+ * avoid aliasing issues with VIPT caches. We need to ensure that
+@@ -68,13 +107,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
+ if (len > mm->cached_hole_size) {
+ start_addr = addr = mm->free_area_cache;
+ } else {
+- start_addr = addr = TASK_UNMAPPED_BASE;
++ start_addr = addr = mm->mmap_base;
+ mm->cached_hole_size = 0;
+ }
+- /* 8 bits of randomness in 20 address space bits */
+- if ((current->flags & PF_RANDOMIZE) &&
+- !(current->personality & ADDR_NO_RANDOMIZE))
+- addr += (get_random_int() % (1 << 8)) << PAGE_SHIFT;
+
+ full_search:
+ if (do_align)
+@@ -111,6 +146,134 @@ full_search:
+ }
+ }
+
++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();
++
++ /*
++ * 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 <= vma->vm_start))
++ return addr;
++ }
++
++ /* check if free_area_cache is useful for us */
++ if (len <= mm->cached_hole_size) {
++ mm->cached_hole_size = 0;
++ mm->free_area_cache = mm->mmap_base;
++ }
++
++ /* either no address requested or can't fit in requested address hole */
++ addr = mm->free_area_cache;
++ if (do_align) {
++ unsigned long base = COLOUR_ALIGN_DOWN(addr - len, pgoff);
++ addr = base + len;
++ }
++
++ /* make sure it can fit in the remaining address space */
++ if (addr > len) {
++ vma = find_vma(mm, addr-len);
++ if (!vma || addr <= vma->vm_start)
++ /* remember the address as a hint for next time */
++ return (mm->free_area_cache = addr-len);
++ }
++
++ if (mm->mmap_base < len)
++ goto bottomup;
++
++ addr = mm->mmap_base - len;
++ if (do_align)
++ addr = COLOUR_ALIGN_DOWN(addr, pgoff);
++
++ do {
++ /*
++ * Lookup failure means no vma is above this address,
++ * else if new region fits below vma->vm_start,
++ * return with success:
++ */
++ vma = find_vma(mm, addr);
++ if (!vma || addr+len <= vma->vm_start)
++ /* remember the address as a hint for next time */
++ return (mm->free_area_cache = addr);
++
++ /* remember the largest hole we saw so far */
++ if (addr + mm->cached_hole_size < vma->vm_start)
++ mm->cached_hole_size = vma->vm_start - addr;
++
++ /* try just below the current vma->vm_start */
++ addr = vma->vm_start - len;
++ if (do_align)
++ addr = COLOUR_ALIGN_DOWN(addr, pgoff);
++ } while (len < vma->vm_start);
++
++bottomup:
++ /*
++ * 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.
++ */
++ mm->cached_hole_size = ~0UL;
++ mm->free_area_cache = TASK_UNMAPPED_BASE;
++ addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
++ /*
++ * Restore the topdown base:
++ */
++ mm->free_area_cache = mm->mmap_base;
++ mm->cached_hole_size = ~0UL;
++
++ return addr;
++}
++
++void arch_pick_mmap_layout(struct mm_struct *mm)
++{
++ unsigned long random_factor = 0UL;
++
++ /* 8 bits of randomness in 20 address space bits */
++ if ((current->flags & PF_RANDOMIZE) &&
++ !(current->personality & ADDR_NO_RANDOMIZE))
++ random_factor = (get_random_int() % (1 << 8)) << PAGE_SHIFT;
++
++ if (mmap_is_legacy()) {
++ mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
++ mm->get_unmapped_area = arch_get_unmapped_area;
++ mm->unmap_area = arch_unmap_area;
++ } else {
++ mm->mmap_base = mmap_base(random_factor);
++ mm->get_unmapped_area = arch_get_unmapped_area_topdown;
++ mm->unmap_area = arch_unmap_area_topdown;
++ }
++}
+
+ /*
+ * You really shouldn't be using read() or write() on /dev/mem. This
+--
+1.7.4.4
+
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