mirror of
https://github.com/Divested-Mobile/DivestOS-Build.git
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1550 lines
52 KiB
Diff
1550 lines
52 KiB
Diff
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From 640c7dfdc7c723143b1ce42f5569ec8565cbbde7 Mon Sep 17 00:00:00 2001
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From: Hugh Dickins <hughd@google.com>
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Date: Mon, 19 Jun 2017 20:32:47 +0200
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Subject: mm: larger stack guard gap, between vmas
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commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.
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Stack guard page is a useful feature to reduce a risk of stack smashing
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into a different mapping. We have been using a single page gap which
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is sufficient to prevent having stack adjacent to a different mapping.
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But this seems to be insufficient in the light of the stack usage in
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userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
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used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
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which is 256kB or stack strings with MAX_ARG_STRLEN.
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This will become especially dangerous for suid binaries and the default
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no limit for the stack size limit because those applications can be
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tricked to consume a large portion of the stack and a single glibc call
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could jump over the guard page. These attacks are not theoretical,
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unfortunatelly.
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Make those attacks less probable by increasing the stack guard gap
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to 1MB (on systems with 4k pages; but make it depend on the page size
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because systems with larger base pages might cap stack allocations in
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the PAGE_SIZE units) which should cover larger alloca() and VLA stack
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allocations. It is obviously not a full fix because the problem is
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somehow inherent, but it should reduce attack space a lot.
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One could argue that the gap size should be configurable from userspace,
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but that can be done later when somebody finds that the new 1MB is wrong
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for some special case applications. For now, add a kernel command line
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option (stack_guard_gap) to specify the stack gap size (in page units).
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Implementation wise, first delete all the old code for stack guard page:
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because although we could get away with accounting one extra page in a
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stack vma, accounting a larger gap can break userspace - case in point,
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a program run with "ulimit -S -v 20000" failed when the 1MB gap was
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counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
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and strict non-overcommit mode.
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Instead of keeping gap inside the stack vma, maintain the stack guard
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gap as a gap between vmas: using vm_start_gap() in place of vm_start
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(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
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places which need to respect the gap - mainly arch_get_unmapped_area(),
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and and the vma tree's subtree_gap support for that.
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Original-patch-by: Oleg Nesterov <oleg@redhat.com>
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Original-patch-by: Michal Hocko <mhocko@suse.com>
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Signed-off-by: Hugh Dickins <hughd@google.com>
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Acked-by: Michal Hocko <mhocko@suse.com>
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Tested-by: Helge Deller <deller@gmx.de> # parisc
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Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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[Hugh Dickins: Backported to 3.2]
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[bwh: Fix more instances of vma->vm_start in sparc64 impl. of
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arch_get_unmapped_area_topdown() and generic impl. of
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hugetlb_get_unmapped_area()]
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Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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---
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Documentation/kernel-parameters.txt | 7 ++
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arch/alpha/kernel/osf_sys.c | 2 +-
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arch/arm/mm/mmap.c | 12 +--
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arch/frv/mm/elf-fdpic.c | 6 +-
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arch/ia64/kernel/sys_ia64.c | 18 +++-
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arch/ia64/mm/hugetlbpage.c | 4 +-
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arch/mips/mm/mmap.c | 19 ++--
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arch/parisc/kernel/sys_parisc.c | 40 ++++++---
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arch/powerpc/mm/slice.c | 24 ++---
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arch/sh/mm/mmap.c | 29 +++---
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arch/sparc/kernel/sys_sparc_32.c | 2 +-
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arch/sparc/kernel/sys_sparc_64.c | 30 ++++---
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arch/sparc/mm/hugetlbpage.c | 27 +++---
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arch/tile/mm/hugetlbpage.c | 26 +++---
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arch/x86/kernel/sys_x86_64.c | 29 +++---
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arch/x86/mm/hugetlbpage.c | 24 ++---
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fs/hugetlbfs/inode.c | 4 +-
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fs/proc/task_mmu.c | 4 -
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include/linux/mm.h | 53 ++++++-----
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mm/memory.c | 49 ----------
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mm/mmap.c | 175 ++++++++++++++++++++----------------
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21 files changed, 312 insertions(+), 272 deletions(-)
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diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
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index ac601c4..356bf4b 100644
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--- a/Documentation/kernel-parameters.txt
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+++ b/Documentation/kernel-parameters.txt
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@@ -2457,6 +2457,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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spia_pedr=
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spia_peddr=
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+ stack_guard_gap= [MM]
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+ override the default stack gap protection. The value
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+ is in page units and it defines how many pages prior
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+ to (for stacks growing down) resp. after (for stacks
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+ growing up) the main stack are reserved for no other
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+ mapping. Default value is 256 pages.
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+
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stacktrace [FTRACE]
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Enabled the stack tracer on boot up.
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diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
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index 01e8715..b9abe5b 100644
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--- a/arch/alpha/kernel/osf_sys.c
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+++ b/arch/alpha/kernel/osf_sys.c
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@@ -1147,7 +1147,7 @@ arch_get_unmapped_area_1(unsigned long addr, unsigned long len,
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/* At this point: (!vma || addr < vma->vm_end). */
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if (limit - len < addr)
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return -ENOMEM;
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- if (!vma || addr + len <= vma->vm_start)
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+ if (!vma || addr + len <= vm_start_gap(vma))
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return addr;
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addr = vma->vm_end;
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vma = vma->vm_next;
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diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
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index 44b628e..4497b5e 100644
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--- a/arch/arm/mm/mmap.c
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+++ b/arch/arm/mm/mmap.c
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@@ -30,7 +30,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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- unsigned long start_addr;
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+ unsigned long start_addr, vm_start;
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int do_align = 0;
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int aliasing = cache_is_vipt_aliasing();
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@@ -62,7 +62,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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- (!vma || addr + len <= vma->vm_start))
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+ (!vma || addr + len <= vm_start_gap(vma)))
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return addr;
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}
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if (len > mm->cached_hole_size) {
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@@ -96,15 +96,17 @@ full_search:
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}
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return -ENOMEM;
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}
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- if (!vma || addr + len <= vma->vm_start) {
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+ if (vma)
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+ vm_start = vm_start_gap(vma);
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+ if (!vma || addr + len <= vm_start) {
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/*
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* Remember the place where we stopped the search:
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*/
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mm->free_area_cache = addr + len;
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return addr;
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}
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- if (addr + mm->cached_hole_size < vma->vm_start)
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- mm->cached_hole_size = vma->vm_start - addr;
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+ if (addr + mm->cached_hole_size < vm_start)
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+ mm->cached_hole_size = vm_start - addr;
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addr = vma->vm_end;
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if (do_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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diff --git a/arch/frv/mm/elf-fdpic.c b/arch/frv/mm/elf-fdpic.c
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index 385fd30..96eca58 100644
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--- a/arch/frv/mm/elf-fdpic.c
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+++ b/arch/frv/mm/elf-fdpic.c
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@@ -74,7 +74,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
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addr = PAGE_ALIGN(addr);
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vma = find_vma(current->mm, addr);
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if (TASK_SIZE - len >= addr &&
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- (!vma || addr + len <= vma->vm_start))
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+ (!vma || addr + len <= vm_start_gap(vma)))
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goto success;
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}
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@@ -89,7 +89,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
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for (; vma; vma = vma->vm_next) {
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if (addr > limit)
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break;
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- if (addr + len <= vma->vm_start)
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+ if (addr + len <= vm_start_gap(vma))
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goto success;
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addr = vma->vm_end;
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}
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@@ -104,7 +104,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
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for (; vma; vma = vma->vm_next) {
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if (addr > limit)
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break;
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- if (addr + len <= vma->vm_start)
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+ if (addr + len <= vm_start_gap(vma))
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goto success;
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addr = vma->vm_end;
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}
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diff --git a/arch/ia64/kernel/sys_ia64.c b/arch/ia64/kernel/sys_ia64.c
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index 609d500..77c0aff 100644
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--- a/arch/ia64/kernel/sys_ia64.c
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+++ b/arch/ia64/kernel/sys_ia64.c
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@@ -27,7 +27,8 @@ arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len
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long map_shared = (flags & MAP_SHARED);
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unsigned long start_addr, align_mask = PAGE_SIZE - 1;
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struct mm_struct *mm = current->mm;
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- struct vm_area_struct *vma;
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+ struct vm_area_struct *vma, *prev;
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+ unsigned long prev_end;
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if (len > RGN_MAP_LIMIT)
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return -ENOMEM;
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@@ -58,7 +59,17 @@ arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len
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full_search:
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start_addr = addr = (addr + align_mask) & ~align_mask;
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- for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
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+ for (vma = find_vma_prev(mm, addr, &prev); ; prev = vma,
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+ vma = vma->vm_next) {
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+ if (prev) {
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+ prev_end = vm_end_gap(prev);
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+ if (addr < prev_end) {
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+ addr = (prev_end + align_mask) & ~align_mask;
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+ /* If vma already violates gap, forget it */
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+ if (vma && addr > vma->vm_start)
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+ addr = vma->vm_start;
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+ }
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+ }
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/* At this point: (!vma || addr < vma->vm_end). */
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if (TASK_SIZE - len < addr || RGN_MAP_LIMIT - len < REGION_OFFSET(addr)) {
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if (start_addr != TASK_UNMAPPED_BASE) {
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@@ -68,12 +79,11 @@ arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len
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}
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return -ENOMEM;
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}
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- if (!vma || addr + len <= vma->vm_start) {
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+ if (!vma || addr + len <= vm_start_gap(vma)) {
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/* Remember the address where we stopped this search: */
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mm->free_area_cache = addr + len;
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return addr;
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}
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- addr = (vma->vm_end + align_mask) & ~align_mask;
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}
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}
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diff --git a/arch/ia64/mm/hugetlbpage.c b/arch/ia64/mm/hugetlbpage.c
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index 5ca674b..66a1ec0 100644
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|
--- a/arch/ia64/mm/hugetlbpage.c
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|
+++ b/arch/ia64/mm/hugetlbpage.c
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|
@@ -171,9 +171,9 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, u
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/* At this point: (!vmm || addr < vmm->vm_end). */
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if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
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|
return -ENOMEM;
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|
- if (!vmm || (addr + len) <= vmm->vm_start)
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|
+ if (!vmm || (addr + len) <= vm_start_gap(vmm))
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return addr;
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|
- addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
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|
+ addr = ALIGN(vm_end_gap(vmm), HPAGE_SIZE);
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|
}
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|
}
|
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|
|
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|
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
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|
index 302d779..a79ddcf 100644
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|
--- a/arch/mips/mm/mmap.c
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|
+++ b/arch/mips/mm/mmap.c
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|
@@ -70,6 +70,7 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
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|
struct mm_struct *mm = current->mm;
|
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|
struct vm_area_struct *vma;
|
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|
unsigned long addr = addr0;
|
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|
+ unsigned long vm_start;
|
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|
int do_color_align;
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|
|
||
|
if (unlikely(len > TASK_SIZE))
|
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|
@@ -103,7 +104,7 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
|
||
|
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (TASK_SIZE - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
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|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
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|
return addr;
|
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|
}
|
||
|
|
||
|
@@ -118,7 +119,7 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
|
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|
/* At this point: (!vma || addr < vma->vm_end). */
|
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|
if (TASK_SIZE - len < addr)
|
||
|
return -ENOMEM;
|
||
|
- if (!vma || addr + len <= vma->vm_start)
|
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|
+ if (!vma || addr + len <= vm_start_gap(vma))
|
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|
return addr;
|
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|
addr = vma->vm_end;
|
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|
if (do_color_align)
|
||
|
@@ -145,7 +146,7 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
|
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|
/* make sure it can fit in the remaining address space */
|
||
|
if (likely(addr > len)) {
|
||
|
vma = find_vma(mm, addr - len);
|
||
|
- if (!vma || addr <= vma->vm_start) {
|
||
|
+ if (!vma || addr <= vm_start_gap(vma)) {
|
||
|
/* cache the address as a hint for next time */
|
||
|
return mm->free_area_cache = addr - len;
|
||
|
}
|
||
|
@@ -165,20 +166,22 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
|
||
|
* return with success:
|
||
|
*/
|
||
|
vma = find_vma(mm, addr);
|
||
|
- if (likely(!vma || addr + len <= vma->vm_start)) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (likely(!vma || addr + len <= vm_start)) {
|
||
|
/* cache 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;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = vma->vm_start - len;
|
||
|
+ addr = vm_start - len;
|
||
|
if (do_color_align)
|
||
|
addr = COLOUR_ALIGN_DOWN(addr, pgoff);
|
||
|
- } while (likely(len < vma->vm_start));
|
||
|
+ } while (likely(len < vm_start));
|
||
|
|
||
|
bottomup:
|
||
|
/*
|
||
|
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
|
||
|
index 7ea75d1..1d4ac8d 100644
|
||
|
--- a/arch/parisc/kernel/sys_parisc.c
|
||
|
+++ b/arch/parisc/kernel/sys_parisc.c
|
||
|
@@ -35,17 +35,27 @@
|
||
|
|
||
|
static unsigned long get_unshared_area(unsigned long addr, unsigned long len)
|
||
|
{
|
||
|
- struct vm_area_struct *vma;
|
||
|
+ struct vm_area_struct *vma, *prev;
|
||
|
+ unsigned long prev_end;
|
||
|
|
||
|
addr = PAGE_ALIGN(addr);
|
||
|
|
||
|
- for (vma = find_vma(current->mm, addr); ; vma = vma->vm_next) {
|
||
|
+ for (vma = find_vma_prev(current->mm, addr, &prev); ; prev = vma,
|
||
|
+ vma = vma->vm_next) {
|
||
|
+ if (prev) {
|
||
|
+ prev_end = vm_end_gap(prev);
|
||
|
+ if (addr < prev_end) {
|
||
|
+ addr = prev_end;
|
||
|
+ /* If vma already violates gap, forget it */
|
||
|
+ if (vma && addr > vma->vm_start)
|
||
|
+ addr = vma->vm_start;
|
||
|
+ }
|
||
|
+ }
|
||
|
/* At this point: (!vma || addr < vma->vm_end). */
|
||
|
if (TASK_SIZE - len < addr)
|
||
|
return -ENOMEM;
|
||
|
- if (!vma || addr + len <= vma->vm_start)
|
||
|
+ if (!vma || addr + len <= vm_start_gap(vma))
|
||
|
return addr;
|
||
|
- addr = vma->vm_end;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
@@ -70,22 +80,32 @@ static int get_offset(struct address_space *mapping)
|
||
|
static unsigned long get_shared_area(struct address_space *mapping,
|
||
|
unsigned long addr, unsigned long len, unsigned long pgoff)
|
||
|
{
|
||
|
- struct vm_area_struct *vma;
|
||
|
+ struct vm_area_struct *vma, *prev;
|
||
|
+ unsigned long prev_end;
|
||
|
int offset = mapping ? get_offset(mapping) : 0;
|
||
|
|
||
|
offset = (offset + (pgoff << PAGE_SHIFT)) & 0x3FF000;
|
||
|
|
||
|
addr = DCACHE_ALIGN(addr - offset) + offset;
|
||
|
|
||
|
- for (vma = find_vma(current->mm, addr); ; vma = vma->vm_next) {
|
||
|
+ for (vma = find_vma_prev(current->mm, addr, &prev); ; prev = vma,
|
||
|
+ vma = vma->vm_next) {
|
||
|
+ if (prev) {
|
||
|
+ prev_end = vm_end_gap(prev);
|
||
|
+ if (addr < prev_end) {
|
||
|
+ addr = DCACHE_ALIGN(prev_end - offset) + offset;
|
||
|
+ if (addr < prev_end) /* handle wraparound */
|
||
|
+ return -ENOMEM;
|
||
|
+ /* If vma already violates gap, forget it */
|
||
|
+ if (vma && addr > vma->vm_start)
|
||
|
+ addr = vma->vm_start;
|
||
|
+ }
|
||
|
+ }
|
||
|
/* At this point: (!vma || addr < vma->vm_end). */
|
||
|
if (TASK_SIZE - len < addr)
|
||
|
return -ENOMEM;
|
||
|
- if (!vma || addr + len <= vma->vm_start)
|
||
|
+ if (!vma || addr + len <= vm_start_gap(vma))
|
||
|
return addr;
|
||
|
- addr = DCACHE_ALIGN(vma->vm_end - offset) + offset;
|
||
|
- if (addr < vma->vm_end) /* handle wraparound */
|
||
|
- return -ENOMEM;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
|
||
|
index 73709f7..57654c9 100644
|
||
|
--- a/arch/powerpc/mm/slice.c
|
||
|
+++ b/arch/powerpc/mm/slice.c
|
||
|
@@ -98,7 +98,7 @@ static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
|
||
|
if ((mm->task_size - len) < addr)
|
||
|
return 0;
|
||
|
vma = find_vma(mm, addr);
|
||
|
- return (!vma || (addr + len) <= vma->vm_start);
|
||
|
+ return (!vma || (addr + len) <= vm_start_gap(vma));
|
||
|
}
|
||
|
|
||
|
static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice)
|
||
|
@@ -227,7 +227,7 @@ static unsigned long slice_find_area_bottomup(struct mm_struct *mm,
|
||
|
int psize, int use_cache)
|
||
|
{
|
||
|
struct vm_area_struct *vma;
|
||
|
- unsigned long start_addr, addr;
|
||
|
+ unsigned long start_addr, addr, vm_start;
|
||
|
struct slice_mask mask;
|
||
|
int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
|
||
|
|
||
|
@@ -256,7 +256,9 @@ full_search:
|
||
|
addr = _ALIGN_UP(addr + 1, 1ul << SLICE_HIGH_SHIFT);
|
||
|
continue;
|
||
|
}
|
||
|
- if (!vma || addr + len <= vma->vm_start) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (!vma || addr + len <= vm_start) {
|
||
|
/*
|
||
|
* Remember the place where we stopped the search:
|
||
|
*/
|
||
|
@@ -264,8 +266,8 @@ full_search:
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (use_cache && (addr + mm->cached_hole_size) < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
addr = vma->vm_end;
|
||
|
}
|
||
|
|
||
|
@@ -284,7 +286,7 @@ static unsigned long slice_find_area_topdown(struct mm_struct *mm,
|
||
|
int psize, int use_cache)
|
||
|
{
|
||
|
struct vm_area_struct *vma;
|
||
|
- unsigned long addr;
|
||
|
+ unsigned long addr, vm_start;
|
||
|
struct slice_mask mask;
|
||
|
int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
|
||
|
|
||
|
@@ -336,7 +338,9 @@ static unsigned long slice_find_area_topdown(struct mm_struct *mm,
|
||
|
* return with success:
|
||
|
*/
|
||
|
vma = find_vma(mm, addr);
|
||
|
- if (!vma || (addr + len) <= vma->vm_start) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (!vma || (addr + len) <= vm_start) {
|
||
|
/* remember the address as a hint for next time */
|
||
|
if (use_cache)
|
||
|
mm->free_area_cache = addr;
|
||
|
@@ -344,11 +348,11 @@ static unsigned long slice_find_area_topdown(struct mm_struct *mm,
|
||
|
}
|
||
|
|
||
|
/* remember the largest hole we saw so far */
|
||
|
- if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (use_cache && (addr + mm->cached_hole_size) < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = vma->vm_start;
|
||
|
+ addr = vm_start;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
|
||
|
index afeb710..22eff46 100644
|
||
|
--- a/arch/sh/mm/mmap.c
|
||
|
+++ b/arch/sh/mm/mmap.c
|
||
|
@@ -47,7 +47,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
|
||
|
{
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
struct vm_area_struct *vma;
|
||
|
- unsigned long start_addr;
|
||
|
+ unsigned long start_addr, vm_start;
|
||
|
int do_colour_align;
|
||
|
|
||
|
if (flags & MAP_FIXED) {
|
||
|
@@ -75,7 +75,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
|
||
|
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (TASK_SIZE - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
|
||
|
@@ -106,15 +106,17 @@ full_search:
|
||
|
}
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
- if (likely(!vma || addr + len <= vma->vm_start)) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (likely(!vma || addr + len <= vm_start)) {
|
||
|
/*
|
||
|
* Remember the place where we stopped the search:
|
||
|
*/
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (addr + mm->cached_hole_size < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
addr = vma->vm_end;
|
||
|
if (do_colour_align)
|
||
|
@@ -130,6 +132,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
struct vm_area_struct *vma;
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
unsigned long addr = addr0;
|
||
|
+ unsigned long vm_start;
|
||
|
int do_colour_align;
|
||
|
|
||
|
if (flags & MAP_FIXED) {
|
||
|
@@ -158,7 +161,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (TASK_SIZE - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
|
||
|
@@ -179,7 +182,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
/* make sure it can fit in the remaining address space */
|
||
|
if (likely(addr > len)) {
|
||
|
vma = find_vma(mm, addr-len);
|
||
|
- if (!vma || addr <= vma->vm_start) {
|
||
|
+ if (!vma || addr <= vm_start_gap(vma)) {
|
||
|
/* remember the address as a hint for next time */
|
||
|
return (mm->free_area_cache = addr-len);
|
||
|
}
|
||
|
@@ -199,20 +202,22 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
* return with success:
|
||
|
*/
|
||
|
vma = find_vma(mm, addr);
|
||
|
- if (likely(!vma || addr+len <= vma->vm_start)) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (likely(!vma || addr + len <= 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;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = vma->vm_start-len;
|
||
|
+ addr = vm_start-len;
|
||
|
if (do_colour_align)
|
||
|
addr = COLOUR_ALIGN_DOWN(addr, pgoff);
|
||
|
- } while (likely(len < vma->vm_start));
|
||
|
+ } while (likely(len < vm_start));
|
||
|
|
||
|
bottomup:
|
||
|
/*
|
||
|
diff --git a/arch/sparc/kernel/sys_sparc_32.c b/arch/sparc/kernel/sys_sparc_32.c
|
||
|
index 42b282f..eeae89b 100644
|
||
|
--- a/arch/sparc/kernel/sys_sparc_32.c
|
||
|
+++ b/arch/sparc/kernel/sys_sparc_32.c
|
||
|
@@ -71,7 +71,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
|
||
|
}
|
||
|
if (TASK_SIZE - PAGE_SIZE - len < addr)
|
||
|
return -ENOMEM;
|
||
|
- if (!vmm || addr + len <= vmm->vm_start)
|
||
|
+ if (!vmm || addr + len <= vm_start_gap(vmm))
|
||
|
return addr;
|
||
|
addr = vmm->vm_end;
|
||
|
if (flags & MAP_SHARED)
|
||
|
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
|
||
|
index a062fe9..39f4999 100644
|
||
|
--- a/arch/sparc/kernel/sys_sparc_64.c
|
||
|
+++ b/arch/sparc/kernel/sys_sparc_64.c
|
||
|
@@ -117,7 +117,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
struct vm_area_struct * vma;
|
||
|
unsigned long task_size = TASK_SIZE;
|
||
|
- unsigned long start_addr;
|
||
|
+ unsigned long start_addr, vm_start;
|
||
|
int do_color_align;
|
||
|
|
||
|
if (flags & MAP_FIXED) {
|
||
|
@@ -147,7 +147,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
|
||
|
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (task_size - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
|
||
|
@@ -181,15 +181,17 @@ full_search:
|
||
|
}
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
- if (likely(!vma || addr + len <= vma->vm_start)) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (likely(!vma || addr + len <= vm_start)) {
|
||
|
/*
|
||
|
* Remember the place where we stopped the search:
|
||
|
*/
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (addr + mm->cached_hole_size < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
addr = vma->vm_end;
|
||
|
if (do_color_align)
|
||
|
@@ -205,7 +207,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
struct vm_area_struct *vma;
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
unsigned long task_size = STACK_TOP32;
|
||
|
- unsigned long addr = addr0;
|
||
|
+ unsigned long addr = addr0, vm_start;
|
||
|
int do_color_align;
|
||
|
|
||
|
/* This should only ever run for 32-bit processes. */
|
||
|
@@ -237,7 +239,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (task_size - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
|
||
|
@@ -258,7 +260,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
/* make sure it can fit in the remaining address space */
|
||
|
if (likely(addr > len)) {
|
||
|
vma = find_vma(mm, addr-len);
|
||
|
- if (!vma || addr <= vma->vm_start) {
|
||
|
+ if (!vma || addr <= vm_start_gap(vma)) {
|
||
|
/* remember the address as a hint for next time */
|
||
|
return (mm->free_area_cache = addr-len);
|
||
|
}
|
||
|
@@ -278,20 +280,22 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
* return with success:
|
||
|
*/
|
||
|
vma = find_vma(mm, addr);
|
||
|
- if (likely(!vma || addr+len <= vma->vm_start)) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (likely(!vma || addr + len <= 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;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = vma->vm_start-len;
|
||
|
+ addr = vm_start - len;
|
||
|
if (do_color_align)
|
||
|
addr = COLOUR_ALIGN_DOWN(addr, pgoff);
|
||
|
- } while (likely(len < vma->vm_start));
|
||
|
+ } while (likely(len < vm_start));
|
||
|
|
||
|
bottomup:
|
||
|
/*
|
||
|
diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
|
||
|
index 07e1453..e13e85d 100644
|
||
|
--- a/arch/sparc/mm/hugetlbpage.c
|
||
|
+++ b/arch/sparc/mm/hugetlbpage.c
|
||
|
@@ -33,7 +33,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
struct vm_area_struct * vma;
|
||
|
unsigned long task_size = TASK_SIZE;
|
||
|
- unsigned long start_addr;
|
||
|
+ unsigned long start_addr, vm_start;
|
||
|
|
||
|
if (test_thread_flag(TIF_32BIT))
|
||
|
task_size = STACK_TOP32;
|
||
|
@@ -67,15 +67,17 @@ full_search:
|
||
|
}
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
- if (likely(!vma || addr + len <= vma->vm_start)) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (likely(!vma || addr + len <= vm_start)) {
|
||
|
/*
|
||
|
* Remember the place where we stopped the search:
|
||
|
*/
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (addr + mm->cached_hole_size < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
addr = ALIGN(vma->vm_end, HPAGE_SIZE);
|
||
|
}
|
||
|
@@ -90,6 +92,7 @@ hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
struct vm_area_struct *vma;
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
unsigned long addr = addr0;
|
||
|
+ unsigned long vm_start;
|
||
|
|
||
|
/* This should only ever run for 32-bit processes. */
|
||
|
BUG_ON(!test_thread_flag(TIF_32BIT));
|
||
|
@@ -106,7 +109,7 @@ hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
/* make sure it can fit in the remaining address space */
|
||
|
if (likely(addr > len)) {
|
||
|
vma = find_vma(mm, addr-len);
|
||
|
- if (!vma || addr <= vma->vm_start) {
|
||
|
+ if (!vma || addr <= vm_start_gap(vma)) {
|
||
|
/* remember the address as a hint for next time */
|
||
|
return (mm->free_area_cache = addr-len);
|
||
|
}
|
||
|
@@ -124,18 +127,20 @@ hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
* return with success:
|
||
|
*/
|
||
|
vma = find_vma(mm, addr);
|
||
|
- if (likely(!vma || addr+len <= vma->vm_start)) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (likely(!vma || addr + len <= 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;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = (vma->vm_start-len) & HPAGE_MASK;
|
||
|
- } while (likely(len < vma->vm_start));
|
||
|
+ addr = (vm_start - len) & HPAGE_MASK;
|
||
|
+ } while (likely(len < vm_start));
|
||
|
|
||
|
bottomup:
|
||
|
/*
|
||
|
@@ -182,7 +187,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
|
||
|
addr = ALIGN(addr, HPAGE_SIZE);
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (task_size - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
if (mm->get_unmapped_area == arch_get_unmapped_area)
|
||
|
diff --git a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c
|
||
|
index 42cfcba..184e033 100644
|
||
|
--- a/arch/tile/mm/hugetlbpage.c
|
||
|
+++ b/arch/tile/mm/hugetlbpage.c
|
||
|
@@ -159,7 +159,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
|
||
|
struct hstate *h = hstate_file(file);
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
struct vm_area_struct *vma;
|
||
|
- unsigned long start_addr;
|
||
|
+ unsigned long start_addr, vm_start;
|
||
|
|
||
|
if (len > mm->cached_hole_size) {
|
||
|
start_addr = mm->free_area_cache;
|
||
|
@@ -185,12 +185,14 @@ full_search:
|
||
|
}
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
- if (!vma || addr + len <= vma->vm_start) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (!vma || addr + len <= vm_start) {
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (addr + mm->cached_hole_size < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
addr = ALIGN(vma->vm_end, huge_page_size(h));
|
||
|
}
|
||
|
}
|
||
|
@@ -204,6 +206,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
|
||
|
struct vm_area_struct *vma, *prev_vma;
|
||
|
unsigned long base = mm->mmap_base, addr = addr0;
|
||
|
unsigned long largest_hole = mm->cached_hole_size;
|
||
|
+ unsigned long vm_start;
|
||
|
int first_time = 1;
|
||
|
|
||
|
/* don't allow allocations above current base */
|
||
|
@@ -234,9 +237,10 @@ try_again:
|
||
|
|
||
|
/*
|
||
|
* new region fits between prev_vma->vm_end and
|
||
|
- * vma->vm_start, use it:
|
||
|
+ * vm_start, use it:
|
||
|
*/
|
||
|
- if (addr + len <= vma->vm_start &&
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (addr + len <= vm_start &&
|
||
|
(!prev_vma || (addr >= prev_vma->vm_end))) {
|
||
|
/* remember the address as a hint for next time */
|
||
|
mm->cached_hole_size = largest_hole;
|
||
|
@@ -251,13 +255,13 @@ try_again:
|
||
|
}
|
||
|
|
||
|
/* remember the largest hole we saw so far */
|
||
|
- if (addr + largest_hole < vma->vm_start)
|
||
|
- largest_hole = vma->vm_start - addr;
|
||
|
+ if (addr + largest_hole < vm_start)
|
||
|
+ largest_hole = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = (vma->vm_start - len) & huge_page_mask(h);
|
||
|
+ addr = (vm_start - len) & huge_page_mask(h);
|
||
|
|
||
|
- } while (len <= vma->vm_start);
|
||
|
+ } while (len <= vm_start);
|
||
|
|
||
|
fail:
|
||
|
/*
|
||
|
@@ -312,7 +316,7 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
|
||
|
addr = ALIGN(addr, huge_page_size(h));
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (TASK_SIZE - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
if (current->mm->get_unmapped_area == arch_get_unmapped_area)
|
||
|
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
|
||
|
index cdb2fc9..0dbfff8 100644
|
||
|
--- a/arch/x86/kernel/sys_x86_64.c
|
||
|
+++ b/arch/x86/kernel/sys_x86_64.c
|
||
|
@@ -126,7 +126,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
|
||
|
{
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
struct vm_area_struct *vma;
|
||
|
- unsigned long start_addr;
|
||
|
+ unsigned long start_addr, vm_start;
|
||
|
unsigned long begin, end;
|
||
|
|
||
|
if (flags & MAP_FIXED)
|
||
|
@@ -141,7 +141,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
|
||
|
addr = PAGE_ALIGN(addr);
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (end - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
if (((flags & MAP_32BIT) || test_thread_flag(TIF_IA32))
|
||
|
@@ -172,15 +172,17 @@ full_search:
|
||
|
}
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
- if (!vma || addr + len <= vma->vm_start) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (!vma || addr + len <= vm_start) {
|
||
|
/*
|
||
|
* Remember the place where we stopped the search:
|
||
|
*/
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (addr + mm->cached_hole_size < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
addr = vma->vm_end;
|
||
|
addr = align_addr(addr, filp, 0);
|
||
|
@@ -196,6 +198,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
struct vm_area_struct *vma;
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
unsigned long addr = addr0;
|
||
|
+ unsigned long vm_start;
|
||
|
|
||
|
/* requested length too big for entire address space */
|
||
|
if (len > TASK_SIZE)
|
||
|
@@ -213,7 +216,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
addr = PAGE_ALIGN(addr);
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (TASK_SIZE - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
|
||
|
@@ -232,7 +235,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
ALIGN_TOPDOWN);
|
||
|
|
||
|
vma = find_vma(mm, tmp_addr);
|
||
|
- if (!vma || tmp_addr + len <= vma->vm_start)
|
||
|
+ if (!vma || tmp_addr + len <= vm_start_gap(vma))
|
||
|
/* remember the address as a hint for next time */
|
||
|
return mm->free_area_cache = tmp_addr;
|
||
|
}
|
||
|
@@ -251,17 +254,19 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
* return with success:
|
||
|
*/
|
||
|
vma = find_vma(mm, addr);
|
||
|
- if (!vma || addr+len <= vma->vm_start)
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (!vma || addr + len <= 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;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = vma->vm_start-len;
|
||
|
- } while (len < vma->vm_start);
|
||
|
+ addr = vm_start - len;
|
||
|
+ } while (len < vm_start);
|
||
|
|
||
|
bottomup:
|
||
|
/*
|
||
|
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
|
||
|
index df7d12c..67b8760 100644
|
||
|
--- a/arch/x86/mm/hugetlbpage.c
|
||
|
+++ b/arch/x86/mm/hugetlbpage.c
|
||
|
@@ -277,7 +277,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
|
||
|
struct hstate *h = hstate_file(file);
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
struct vm_area_struct *vma;
|
||
|
- unsigned long start_addr;
|
||
|
+ unsigned long start_addr, vm_start;
|
||
|
|
||
|
if (len > mm->cached_hole_size) {
|
||
|
start_addr = mm->free_area_cache;
|
||
|
@@ -303,12 +303,14 @@ full_search:
|
||
|
}
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
- if (!vma || addr + len <= vma->vm_start) {
|
||
|
+ if (vma)
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (!vma || addr + len <= vm_start) {
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (addr + mm->cached_hole_size < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
addr = ALIGN(vma->vm_end, huge_page_size(h));
|
||
|
}
|
||
|
}
|
||
|
@@ -322,6 +324,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
|
||
|
struct vm_area_struct *vma, *prev_vma;
|
||
|
unsigned long base = mm->mmap_base, addr = addr0;
|
||
|
unsigned long largest_hole = mm->cached_hole_size;
|
||
|
+ unsigned long vm_start;
|
||
|
int first_time = 1;
|
||
|
|
||
|
/* don't allow allocations above current base */
|
||
|
@@ -351,7 +354,8 @@ try_again:
|
||
|
* new region fits between prev_vma->vm_end and
|
||
|
* vma->vm_start, use it:
|
||
|
*/
|
||
|
- if (addr + len <= vma->vm_start &&
|
||
|
+ vm_start = vm_start_gap(vma);
|
||
|
+ if (addr + len <= vm_start &&
|
||
|
(!prev_vma || (addr >= prev_vma->vm_end))) {
|
||
|
/* remember the address as a hint for next time */
|
||
|
mm->cached_hole_size = largest_hole;
|
||
|
@@ -365,12 +369,12 @@ try_again:
|
||
|
}
|
||
|
|
||
|
/* remember the largest hole we saw so far */
|
||
|
- if (addr + largest_hole < vma->vm_start)
|
||
|
- largest_hole = vma->vm_start - addr;
|
||
|
+ if (addr + largest_hole < vm_start)
|
||
|
+ largest_hole = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = (vma->vm_start - len) & huge_page_mask(h);
|
||
|
- } while (len <= vma->vm_start);
|
||
|
+ addr = (vm_start - len) & huge_page_mask(h);
|
||
|
+ } while (len <= vm_start);
|
||
|
|
||
|
fail:
|
||
|
/*
|
||
|
@@ -426,7 +430,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
|
||
|
addr = ALIGN(addr, huge_page_size(h));
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (TASK_SIZE - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
if (mm->get_unmapped_area == arch_get_unmapped_area)
|
||
|
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
|
||
|
index 5557332..99c51d6 100644
|
||
|
--- a/fs/hugetlbfs/inode.c
|
||
|
+++ b/fs/hugetlbfs/inode.c
|
||
|
@@ -150,7 +150,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
|
||
|
addr = ALIGN(addr, huge_page_size(h));
|
||
|
vma = find_vma(mm, addr);
|
||
|
if (TASK_SIZE - len >= addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)))
|
||
|
return addr;
|
||
|
}
|
||
|
|
||
|
@@ -176,7 +176,7 @@ full_search:
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
|
||
|
- if (!vma || addr + len <= vma->vm_start)
|
||
|
+ if (!vma || addr + len <= vm_start_gap(vma))
|
||
|
return addr;
|
||
|
addr = ALIGN(vma->vm_end, huge_page_size(h));
|
||
|
}
|
||
|
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
|
||
|
index de404f2..6037a13 100644
|
||
|
--- a/fs/proc/task_mmu.c
|
||
|
+++ b/fs/proc/task_mmu.c
|
||
|
@@ -230,11 +230,7 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
|
||
|
|
||
|
/* We don't show the stack guard page in /proc/maps */
|
||
|
start = vma->vm_start;
|
||
|
- if (stack_guard_page_start(vma, start))
|
||
|
- start += PAGE_SIZE;
|
||
|
end = vma->vm_end;
|
||
|
- if (stack_guard_page_end(vma, end))
|
||
|
- end -= PAGE_SIZE;
|
||
|
|
||
|
seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
|
||
|
start,
|
||
|
diff --git a/include/linux/mm.h b/include/linux/mm.h
|
||
|
index 16394da..19f9043 100644
|
||
|
--- a/include/linux/mm.h
|
||
|
+++ b/include/linux/mm.h
|
||
|
@@ -1015,34 +1015,6 @@ int set_page_dirty(struct page *page);
|
||
|
int set_page_dirty_lock(struct page *page);
|
||
|
int clear_page_dirty_for_io(struct page *page);
|
||
|
|
||
|
-/* Is the vma a continuation of the stack vma above it? */
|
||
|
-static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr)
|
||
|
-{
|
||
|
- return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN);
|
||
|
-}
|
||
|
-
|
||
|
-static inline int stack_guard_page_start(struct vm_area_struct *vma,
|
||
|
- unsigned long addr)
|
||
|
-{
|
||
|
- return (vma->vm_flags & VM_GROWSDOWN) &&
|
||
|
- (vma->vm_start == addr) &&
|
||
|
- !vma_growsdown(vma->vm_prev, addr);
|
||
|
-}
|
||
|
-
|
||
|
-/* Is the vma a continuation of the stack vma below it? */
|
||
|
-static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr)
|
||
|
-{
|
||
|
- return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP);
|
||
|
-}
|
||
|
-
|
||
|
-static inline int stack_guard_page_end(struct vm_area_struct *vma,
|
||
|
- unsigned long addr)
|
||
|
-{
|
||
|
- return (vma->vm_flags & VM_GROWSUP) &&
|
||
|
- (vma->vm_end == addr) &&
|
||
|
- !vma_growsup(vma->vm_next, addr);
|
||
|
-}
|
||
|
-
|
||
|
extern unsigned long move_page_tables(struct vm_area_struct *vma,
|
||
|
unsigned long old_addr, struct vm_area_struct *new_vma,
|
||
|
unsigned long new_addr, unsigned long len);
|
||
|
@@ -1462,6 +1434,7 @@ unsigned long ra_submit(struct file_ra_state *ra,
|
||
|
struct address_space *mapping,
|
||
|
struct file *filp);
|
||
|
|
||
|
+extern unsigned long stack_guard_gap;
|
||
|
/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
|
||
|
extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
|
||
|
|
||
|
@@ -1490,6 +1463,30 @@ static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * m
|
||
|
return vma;
|
||
|
}
|
||
|
|
||
|
+static inline unsigned long vm_start_gap(struct vm_area_struct *vma)
|
||
|
+{
|
||
|
+ unsigned long vm_start = vma->vm_start;
|
||
|
+
|
||
|
+ if (vma->vm_flags & VM_GROWSDOWN) {
|
||
|
+ vm_start -= stack_guard_gap;
|
||
|
+ if (vm_start > vma->vm_start)
|
||
|
+ vm_start = 0;
|
||
|
+ }
|
||
|
+ return vm_start;
|
||
|
+}
|
||
|
+
|
||
|
+static inline unsigned long vm_end_gap(struct vm_area_struct *vma)
|
||
|
+{
|
||
|
+ unsigned long vm_end = vma->vm_end;
|
||
|
+
|
||
|
+ if (vma->vm_flags & VM_GROWSUP) {
|
||
|
+ vm_end += stack_guard_gap;
|
||
|
+ if (vm_end < vma->vm_end)
|
||
|
+ vm_end = -PAGE_SIZE;
|
||
|
+ }
|
||
|
+ return vm_end;
|
||
|
+}
|
||
|
+
|
||
|
static inline unsigned long vma_pages(struct vm_area_struct *vma)
|
||
|
{
|
||
|
return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
|
||
|
diff --git a/mm/memory.c b/mm/memory.c
|
||
|
index 2917e9b..6325103d 100644
|
||
|
--- a/mm/memory.c
|
||
|
+++ b/mm/memory.c
|
||
|
@@ -1605,12 +1605,6 @@ no_page_table:
|
||
|
return page;
|
||
|
}
|
||
|
|
||
|
-static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long addr)
|
||
|
-{
|
||
|
- return stack_guard_page_start(vma, addr) ||
|
||
|
- stack_guard_page_end(vma, addr+PAGE_SIZE);
|
||
|
-}
|
||
|
-
|
||
|
/**
|
||
|
* __get_user_pages() - pin user pages in memory
|
||
|
* @tsk: task_struct of target task
|
||
|
@@ -1761,11 +1755,6 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
|
||
|
int ret;
|
||
|
unsigned int fault_flags = 0;
|
||
|
|
||
|
- /* For mlock, just skip the stack guard page. */
|
||
|
- if (foll_flags & FOLL_MLOCK) {
|
||
|
- if (stack_guard_page(vma, start))
|
||
|
- goto next_page;
|
||
|
- }
|
||
|
if (foll_flags & FOLL_WRITE)
|
||
|
fault_flags |= FAULT_FLAG_WRITE;
|
||
|
if (nonblocking)
|
||
|
@@ -3122,40 +3111,6 @@ out_release:
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
- * This is like a special single-page "expand_{down|up}wards()",
|
||
|
- * except we must first make sure that 'address{-|+}PAGE_SIZE'
|
||
|
- * doesn't hit another vma.
|
||
|
- */
|
||
|
-static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned long address)
|
||
|
-{
|
||
|
- address &= PAGE_MASK;
|
||
|
- if ((vma->vm_flags & VM_GROWSDOWN) && address == vma->vm_start) {
|
||
|
- struct vm_area_struct *prev = vma->vm_prev;
|
||
|
-
|
||
|
- /*
|
||
|
- * Is there a mapping abutting this one below?
|
||
|
- *
|
||
|
- * That's only ok if it's the same stack mapping
|
||
|
- * that has gotten split..
|
||
|
- */
|
||
|
- if (prev && prev->vm_end == address)
|
||
|
- return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
|
||
|
-
|
||
|
- return expand_downwards(vma, address - PAGE_SIZE);
|
||
|
- }
|
||
|
- if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) {
|
||
|
- struct vm_area_struct *next = vma->vm_next;
|
||
|
-
|
||
|
- /* As VM_GROWSDOWN but s/below/above/ */
|
||
|
- if (next && next->vm_start == address + PAGE_SIZE)
|
||
|
- return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM;
|
||
|
-
|
||
|
- return expand_upwards(vma, address + PAGE_SIZE);
|
||
|
- }
|
||
|
- return 0;
|
||
|
-}
|
||
|
-
|
||
|
-/*
|
||
|
* We enter with non-exclusive mmap_sem (to exclude vma changes,
|
||
|
* but allow concurrent faults), and pte mapped but not yet locked.
|
||
|
* We return with mmap_sem still held, but pte unmapped and unlocked.
|
||
|
@@ -3174,10 +3129,6 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
|
||
|
if (vma->vm_flags & VM_SHARED)
|
||
|
return VM_FAULT_SIGBUS;
|
||
|
|
||
|
- /* Check if we need to add a guard page to the stack */
|
||
|
- if (check_stack_guard_page(vma, address) < 0)
|
||
|
- return VM_FAULT_SIGSEGV;
|
||
|
-
|
||
|
/* Use the zero-page for reads */
|
||
|
if (!(flags & FAULT_FLAG_WRITE)) {
|
||
|
entry = pte_mkspecial(pfn_pte(my_zero_pfn(address),
|
||
|
diff --git a/mm/mmap.c b/mm/mmap.c
|
||
|
index e949a20..cbcf486 100644
|
||
|
--- a/mm/mmap.c
|
||
|
+++ b/mm/mmap.c
|
||
|
@@ -245,6 +245,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
|
||
|
unsigned long rlim, retval;
|
||
|
unsigned long newbrk, oldbrk;
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
+ struct vm_area_struct *next;
|
||
|
unsigned long min_brk;
|
||
|
|
||
|
down_write(&mm->mmap_sem);
|
||
|
@@ -289,7 +290,8 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
|
||
|
}
|
||
|
|
||
|
/* Check against existing mmap mappings. */
|
||
|
- if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
|
||
|
+ next = find_vma(mm, oldbrk);
|
||
|
+ if (next && newbrk + PAGE_SIZE > vm_start_gap(next))
|
||
|
goto out;
|
||
|
|
||
|
/* Ok, looks good - let it rip. */
|
||
|
@@ -1368,8 +1370,8 @@ 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;
|
||
|
- unsigned long start_addr;
|
||
|
+ struct vm_area_struct *vma, *prev;
|
||
|
+ unsigned long start_addr, vm_start, prev_end;
|
||
|
|
||
|
if (len > TASK_SIZE - mmap_min_addr)
|
||
|
return -ENOMEM;
|
||
|
@@ -1379,9 +1381,10 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
|
||
|
|
||
|
if (addr) {
|
||
|
addr = PAGE_ALIGN(addr);
|
||
|
- vma = find_vma(mm, addr);
|
||
|
+ vma = find_vma_prev(mm, addr, &prev);
|
||
|
if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)) &&
|
||
|
+ (!prev || addr >= vm_end_gap(prev)))
|
||
|
return addr;
|
||
|
}
|
||
|
if (len > mm->cached_hole_size) {
|
||
|
@@ -1392,7 +1395,17 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
|
||
|
}
|
||
|
|
||
|
full_search:
|
||
|
- for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
|
||
|
+ for (vma = find_vma_prev(mm, addr, &prev); ; prev = vma,
|
||
|
+ vma = vma->vm_next) {
|
||
|
+ if (prev) {
|
||
|
+ prev_end = vm_end_gap(prev);
|
||
|
+ if (addr < prev_end) {
|
||
|
+ addr = prev_end;
|
||
|
+ /* If vma already violates gap, forget it */
|
||
|
+ if (vma && addr > vma->vm_start)
|
||
|
+ addr = vma->vm_start;
|
||
|
+ }
|
||
|
+ }
|
||
|
/* At this point: (!vma || addr < vma->vm_end). */
|
||
|
if (TASK_SIZE - len < addr) {
|
||
|
/*
|
||
|
@@ -1407,16 +1420,16 @@ full_search:
|
||
|
}
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
- if (!vma || addr + len <= vma->vm_start) {
|
||
|
+ vm_start = vma ? vm_start_gap(vma) : TASK_SIZE;
|
||
|
+ if (addr + len <= vm_start) {
|
||
|
/*
|
||
|
* Remember the place where we stopped the search:
|
||
|
*/
|
||
|
mm->free_area_cache = addr + len;
|
||
|
return addr;
|
||
|
}
|
||
|
- if (addr + mm->cached_hole_size < vma->vm_start)
|
||
|
- mm->cached_hole_size = vma->vm_start - addr;
|
||
|
- addr = vma->vm_end;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
}
|
||
|
}
|
||
|
#endif
|
||
|
@@ -1442,9 +1455,10 @@ 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 vm_area_struct *vma, *prev;
|
||
|
struct mm_struct *mm = current->mm;
|
||
|
unsigned long addr = addr0;
|
||
|
+ unsigned long vm_start, prev_end;
|
||
|
unsigned long low_limit = max(PAGE_SIZE, mmap_min_addr);
|
||
|
|
||
|
/* requested length too big for entire address space */
|
||
|
@@ -1457,9 +1471,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
/* requesting a specific address */
|
||
|
if (addr) {
|
||
|
addr = PAGE_ALIGN(addr);
|
||
|
- vma = find_vma(mm, addr);
|
||
|
+ vma = find_vma_prev(mm, addr, &prev);
|
||
|
if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
|
||
|
- (!vma || addr + len <= vma->vm_start))
|
||
|
+ (!vma || addr + len <= vm_start_gap(vma)) &&
|
||
|
+ (!prev || addr >= vm_end_gap(prev)))
|
||
|
return addr;
|
||
|
}
|
||
|
|
||
|
@@ -1474,8 +1489,9 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
|
||
|
/* make sure it can fit in the remaining address space */
|
||
|
if (addr >= low_limit + len) {
|
||
|
- vma = find_vma(mm, addr-len);
|
||
|
- if (!vma || addr <= vma->vm_start)
|
||
|
+ vma = find_vma_prev(mm, addr-len, &prev);
|
||
|
+ if ((!vma || addr <= vm_start_gap(vma)) &&
|
||
|
+ (!prev || addr-len >= vm_end_gap(prev)))
|
||
|
/* remember the address as a hint for next time */
|
||
|
return (mm->free_area_cache = addr-len);
|
||
|
}
|
||
|
@@ -1491,18 +1507,21 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
|
||
|
* else if new region fits below vma->vm_start,
|
||
|
* return with success:
|
||
|
*/
|
||
|
- vma = find_vma(mm, addr);
|
||
|
- if (!vma || addr+len <= vma->vm_start)
|
||
|
+ vma = find_vma_prev(mm, addr, &prev);
|
||
|
+ vm_start = vma ? vm_start_gap(vma) : mm->mmap_base;
|
||
|
+ prev_end = prev ? vm_end_gap(prev) : low_limit;
|
||
|
+
|
||
|
+ if (addr + len <= vm_start && addr >= prev_end)
|
||
|
/* 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;
|
||
|
+ if (addr + mm->cached_hole_size < vm_start)
|
||
|
+ mm->cached_hole_size = vm_start - addr;
|
||
|
|
||
|
/* try just below the current vma->vm_start */
|
||
|
- addr = vma->vm_start-len;
|
||
|
- } while (vma->vm_start >= low_limit + len);
|
||
|
+ addr = vm_start - len;
|
||
|
+ } while (vm_start >= low_limit + len);
|
||
|
|
||
|
bottomup:
|
||
|
/*
|
||
|
@@ -1647,21 +1666,19 @@ out:
|
||
|
* update accounting. This is shared with both the
|
||
|
* grow-up and grow-down cases.
|
||
|
*/
|
||
|
-static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, unsigned long grow)
|
||
|
+static int acct_stack_growth(struct vm_area_struct *vma,
|
||
|
+ unsigned long size, unsigned long grow)
|
||
|
{
|
||
|
struct mm_struct *mm = vma->vm_mm;
|
||
|
struct rlimit *rlim = current->signal->rlim;
|
||
|
- unsigned long new_start, actual_size;
|
||
|
+ unsigned long new_start;
|
||
|
|
||
|
/* address space limit tests */
|
||
|
if (!may_expand_vm(mm, grow))
|
||
|
return -ENOMEM;
|
||
|
|
||
|
/* Stack limit test */
|
||
|
- actual_size = size;
|
||
|
- if (size && (vma->vm_flags & (VM_GROWSUP | VM_GROWSDOWN)))
|
||
|
- actual_size -= PAGE_SIZE;
|
||
|
- if (actual_size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur))
|
||
|
+ if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur))
|
||
|
return -ENOMEM;
|
||
|
|
||
|
/* mlock limit tests */
|
||
|
@@ -1703,32 +1720,40 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns
|
||
|
*/
|
||
|
int expand_upwards(struct vm_area_struct *vma, unsigned long address)
|
||
|
{
|
||
|
- int error;
|
||
|
+ struct vm_area_struct *next;
|
||
|
+ unsigned long gap_addr;
|
||
|
+ int error = 0;
|
||
|
|
||
|
if (!(vma->vm_flags & VM_GROWSUP))
|
||
|
return -EFAULT;
|
||
|
|
||
|
- /*
|
||
|
- * We must make sure the anon_vma is allocated
|
||
|
- * so that the anon_vma locking is not a noop.
|
||
|
- */
|
||
|
+ /* Guard against wrapping around to address 0. */
|
||
|
+ address &= PAGE_MASK;
|
||
|
+ address += PAGE_SIZE;
|
||
|
+ if (!address)
|
||
|
+ return -ENOMEM;
|
||
|
+
|
||
|
+ /* Enforce stack_guard_gap */
|
||
|
+ gap_addr = address + stack_guard_gap;
|
||
|
+ if (gap_addr < address)
|
||
|
+ return -ENOMEM;
|
||
|
+ next = vma->vm_next;
|
||
|
+ if (next && next->vm_start < gap_addr) {
|
||
|
+ if (!(next->vm_flags & VM_GROWSUP))
|
||
|
+ return -ENOMEM;
|
||
|
+ /* Check that both stack segments have the same anon_vma? */
|
||
|
+ }
|
||
|
+
|
||
|
+ /* We must make sure the anon_vma is allocated. */
|
||
|
if (unlikely(anon_vma_prepare(vma)))
|
||
|
return -ENOMEM;
|
||
|
- vma_lock_anon_vma(vma);
|
||
|
|
||
|
/*
|
||
|
* vma->vm_start/vm_end cannot change under us because the caller
|
||
|
* is required to hold the mmap_sem in read mode. We need the
|
||
|
* anon_vma lock to serialize against concurrent expand_stacks.
|
||
|
- * Also guard against wrapping around to address 0.
|
||
|
*/
|
||
|
- if (address < PAGE_ALIGN(address+4))
|
||
|
- address = PAGE_ALIGN(address+4);
|
||
|
- else {
|
||
|
- vma_unlock_anon_vma(vma);
|
||
|
- return -ENOMEM;
|
||
|
- }
|
||
|
- error = 0;
|
||
|
+ vma_lock_anon_vma(vma);
|
||
|
|
||
|
/* Somebody else might have raced and expanded it already */
|
||
|
if (address > vma->vm_end) {
|
||
|
@@ -1758,27 +1783,36 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
|
||
|
int expand_downwards(struct vm_area_struct *vma,
|
||
|
unsigned long address)
|
||
|
{
|
||
|
+ struct vm_area_struct *prev;
|
||
|
+ unsigned long gap_addr;
|
||
|
int error;
|
||
|
|
||
|
- /*
|
||
|
- * We must make sure the anon_vma is allocated
|
||
|
- * so that the anon_vma locking is not a noop.
|
||
|
- */
|
||
|
- if (unlikely(anon_vma_prepare(vma)))
|
||
|
- return -ENOMEM;
|
||
|
-
|
||
|
address &= PAGE_MASK;
|
||
|
error = security_file_mmap(NULL, 0, 0, 0, address, 1);
|
||
|
if (error)
|
||
|
return error;
|
||
|
|
||
|
- vma_lock_anon_vma(vma);
|
||
|
+ /* Enforce stack_guard_gap */
|
||
|
+ gap_addr = address - stack_guard_gap;
|
||
|
+ if (gap_addr > address)
|
||
|
+ return -ENOMEM;
|
||
|
+ prev = vma->vm_prev;
|
||
|
+ if (prev && prev->vm_end > gap_addr) {
|
||
|
+ if (!(prev->vm_flags & VM_GROWSDOWN))
|
||
|
+ return -ENOMEM;
|
||
|
+ /* Check that both stack segments have the same anon_vma? */
|
||
|
+ }
|
||
|
+
|
||
|
+ /* We must make sure the anon_vma is allocated. */
|
||
|
+ if (unlikely(anon_vma_prepare(vma)))
|
||
|
+ return -ENOMEM;
|
||
|
|
||
|
/*
|
||
|
* vma->vm_start/vm_end cannot change under us because the caller
|
||
|
* is required to hold the mmap_sem in read mode. We need the
|
||
|
* anon_vma lock to serialize against concurrent expand_stacks.
|
||
|
*/
|
||
|
+ vma_lock_anon_vma(vma);
|
||
|
|
||
|
/* Somebody else might have raced and expanded it already */
|
||
|
if (address < vma->vm_start) {
|
||
|
@@ -1802,28 +1836,25 @@ int expand_downwards(struct vm_area_struct *vma,
|
||
|
return error;
|
||
|
}
|
||
|
|
||
|
-/*
|
||
|
- * Note how expand_stack() refuses to expand the stack all the way to
|
||
|
- * abut the next virtual mapping, *unless* that mapping itself is also
|
||
|
- * a stack mapping. We want to leave room for a guard page, after all
|
||
|
- * (the guard page itself is not added here, that is done by the
|
||
|
- * actual page faulting logic)
|
||
|
- *
|
||
|
- * This matches the behavior of the guard page logic (see mm/memory.c:
|
||
|
- * check_stack_guard_page()), which only allows the guard page to be
|
||
|
- * removed under these circumstances.
|
||
|
- */
|
||
|
+/* enforced gap between the expanding stack and other mappings. */
|
||
|
+unsigned long stack_guard_gap = 256UL<<PAGE_SHIFT;
|
||
|
+
|
||
|
+static int __init cmdline_parse_stack_guard_gap(char *p)
|
||
|
+{
|
||
|
+ unsigned long val;
|
||
|
+ char *endptr;
|
||
|
+
|
||
|
+ val = simple_strtoul(p, &endptr, 10);
|
||
|
+ if (!*endptr)
|
||
|
+ stack_guard_gap = val << PAGE_SHIFT;
|
||
|
+
|
||
|
+ return 0;
|
||
|
+}
|
||
|
+__setup("stack_guard_gap=", cmdline_parse_stack_guard_gap);
|
||
|
+
|
||
|
#ifdef CONFIG_STACK_GROWSUP
|
||
|
int expand_stack(struct vm_area_struct *vma, unsigned long address)
|
||
|
{
|
||
|
- struct vm_area_struct *next;
|
||
|
-
|
||
|
- address &= PAGE_MASK;
|
||
|
- next = vma->vm_next;
|
||
|
- if (next && next->vm_start == address + PAGE_SIZE) {
|
||
|
- if (!(next->vm_flags & VM_GROWSUP))
|
||
|
- return -ENOMEM;
|
||
|
- }
|
||
|
return expand_upwards(vma, address);
|
||
|
}
|
||
|
|
||
|
@@ -1846,14 +1877,6 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr)
|
||
|
#else
|
||
|
int expand_stack(struct vm_area_struct *vma, unsigned long address)
|
||
|
{
|
||
|
- struct vm_area_struct *prev;
|
||
|
-
|
||
|
- address &= PAGE_MASK;
|
||
|
- prev = vma->vm_prev;
|
||
|
- if (prev && prev->vm_end == address) {
|
||
|
- if (!(prev->vm_flags & VM_GROWSDOWN))
|
||
|
- return -ENOMEM;
|
||
|
- }
|
||
|
return expand_downwards(vma, address);
|
||
|
}
|
||
|
|
||
|
--
|
||
|
cgit v1.1
|
||
|
|