diff options
| -rw-r--r-- | main/linux-rpi/APKBUILD | 8 | ||||
| -rw-r--r-- | main/linux-rpi/mm-guard-against-under-sized-gap-in-unmapped_area-_topdown.patch | 27 | ||||
| -rw-r--r-- | main/linux-rpi/mm-larger-stack-guard-gap-between-vmas.patch | 885 |
3 files changed, 2 insertions, 918 deletions
diff --git a/main/linux-rpi/APKBUILD b/main/linux-rpi/APKBUILD index eba8e6a764..8e53f8ded3 100644 --- a/main/linux-rpi/APKBUILD +++ b/main/linux-rpi/APKBUILD @@ -18,11 +18,9 @@ install= # rpi-cirrus-4.4.y https://github.com/HiassofT/rpi-linux/tree/cirrus-4.4.y source="https://kernel.org/pub/linux/kernel/v4.x/linux-$_kernver.tar.xz https://kernel.org/pub/linux/kernel/v4.x/patch-$pkgver.xz - https://dev.alpinelinux.org/~clandmeter/patches/linux-4.9.y-rpi-201704120.patch + https://dev.alpinelinux.org/~clandmeter/patches/linux-v${pkgver}-rpi.patch.gz gpio-mcp23s08-pullups.patch issue-4973.patch - mm-larger-stack-guard-gap-between-vmas.patch - mm-guard-against-under-sized-gap-in-unmapped_area-_topdown.patch config-rpi.armhf config-rpi2.armhf @@ -197,11 +195,9 @@ _dev() { sha512sums="bf67ff812cc3cb7e5059e82cc5db0d9a7c5637f7ed9a42e4730c715bf7047c81ed3a571225f92a33ef0b6d65f35595bc32d773356646df2627da55e9bc7f1f1a linux-4.9.tar.xz ab9c26493069f87a9d8c6c97db1a84f03a1b1221f47facc68e65d79ef75d9c7bd93c1f39eee334e4f45381b2c84ff3acb8870478c61c4d8a648984db55be5ad3 patch-4.9.40.xz -1586b4c549285bb3015e99288c08cbbad719c7b40156fdb4ab7849a07363d2cc29045ae0037f0873994d3c36812be2ed2ee530c6fbfce5a86e6ebf83480d0db2 linux-4.9.y-rpi-201704120.patch +2cbeb943eb296ded385593b7e7e2309d78ea040581bdb75e131544ee5d4b8a867e80a76cfbc170271b85ef0c6925526d20e1cb6945031a5eb40dd18c225b0fbe linux-v4.9.40-rpi.patch.gz 36724ba56cb8fdf3a3d347cffb67ae1cc3d7b1052d526b6b5134ebf6baae9f9724b586c97833453dc7697ab24699426f0749af78b6a80be36967a80033a0cf40 gpio-mcp23s08-pullups.patch 501c91bf2538a18102da59bbccc3097f9c3c90079acc0e946ff075074160c09b8a66934e5ce5470e170f0e4f93d114709a95230367426d0bb7ea02c4bdf4cc9b issue-4973.patch -69f03e4a0020c0b9f196a02f326503c03f5fb192d191ccbc21a30a422b115e6873dfd925df594da1d8b0c3477ead98c8e0757fd1e3128fd703339b352fda0299 mm-larger-stack-guard-gap-between-vmas.patch -567b70b5f634d7d8f79f5f70f7fdf0aee46dab6b865d6a62ee5a5a0dded69eb47008d86f4d639b7261beedce6a7df44a1d3e51e0fe5902b4c51b6b83e3b146a3 mm-guard-against-under-sized-gap-in-unmapped_area-_topdown.patch 54dc88144fc7d502499878f588e5f0f3312991ce49b9245a2790cb1d1224b4f71a4751b7cd29b29e2b2b17d64b65d8d49198f6fbd545a9322faf25041e4bdc06 config-rpi.armhf 626369f71ef271f6722e8e297cbdaf9cc4d57c9bfda264eac473f006f54a5697f45a757e0930d98523ed8c63a880a89a8258a55ab99bd720a84acd4ee46d5010 config-rpi2.armhf a8e7f434c325c9dd7a9109efecad408e42a50ecd1391cb0c7d1d7de79609caee007486c8a6538231c74bdc5d7b84cbca053958e1b239bc0507e6d3598ace383a markdt" diff --git a/main/linux-rpi/mm-guard-against-under-sized-gap-in-unmapped_area-_topdown.patch b/main/linux-rpi/mm-guard-against-under-sized-gap-in-unmapped_area-_topdown.patch deleted file mode 100644 index 5472fb5f19..0000000000 --- a/main/linux-rpi/mm-guard-against-under-sized-gap-in-unmapped_area-_topdown.patch +++ /dev/null @@ -1,27 +0,0 @@ -Author: Hugh Dickins <hughd@google.com> -Date: Mon, 19 Jun 2017 21:40:56 -0700 -Description: mm: Guard against under-sized gap in unmapped_area{,_topdown}() -Origin: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1426125.html - ---- a/mm/mmap.c -+++ b/mm/mmap.c -@@ -1817,7 +1817,8 @@ unsigned long unmapped_area(struct vm_un - /* Check if current node has a suitable gap */ - if (gap_start > high_limit) - return -ENOMEM; -- if (gap_end >= low_limit && gap_end - gap_start >= length) -+ if (gap_end >= low_limit && -+ gap_end > gap_start && gap_end - gap_start >= length) - goto found; - - /* Visit right subtree if it looks promising */ -@@ -1920,7 +1921,8 @@ unsigned long unmapped_area_topdown(stru - gap_end = vm_start_gap(vma); - if (gap_end < low_limit) - return -ENOMEM; -- if (gap_start <= high_limit && gap_end - gap_start >= length) -+ if (gap_start <= high_limit && -+ gap_end > gap_start && gap_end - gap_start >= length) - goto found; - - /* Visit left subtree if it looks promising */ diff --git a/main/linux-rpi/mm-larger-stack-guard-gap-between-vmas.patch b/main/linux-rpi/mm-larger-stack-guard-gap-between-vmas.patch deleted file mode 100644 index af4e9c6980..0000000000 --- a/main/linux-rpi/mm-larger-stack-guard-gap-between-vmas.patch +++ /dev/null @@ -1,885 +0,0 @@ -From: Hugh Dickins <hughd@google.com> -Date: Mon, 19 Jun 2017 04:03:24 -0700 -Subject: mm: larger stack guard gap, between vmas - -commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. - -Stack guard page is a useful feature to reduce a risk of stack smashing -into a different mapping. We have been using a single page gap which -is sufficient to prevent having stack adjacent to a different mapping. -But this seems to be insufficient in the light of the stack usage in -userspace. E.g. glibc uses as large as 64kB alloca() in many commonly -used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] -which is 256kB or stack strings with MAX_ARG_STRLEN. - -This will become especially dangerous for suid binaries and the default -no limit for the stack size limit because those applications can be -tricked to consume a large portion of the stack and a single glibc call -could jump over the guard page. These attacks are not theoretical, -unfortunatelly. - -Make those attacks less probable by increasing the stack guard gap -to 1MB (on systems with 4k pages; but make it depend on the page size -because systems with larger base pages might cap stack allocations in -the PAGE_SIZE units) which should cover larger alloca() and VLA stack -allocations. It is obviously not a full fix because the problem is -somehow inherent, but it should reduce attack space a lot. - -One could argue that the gap size should be configurable from userspace, -but that can be done later when somebody finds that the new 1MB is wrong -for some special case applications. For now, add a kernel command line -option (stack_guard_gap) to specify the stack gap size (in page units). - -Implementation wise, first delete all the old code for stack guard page: -because although we could get away with accounting one extra page in a -stack vma, accounting a larger gap can break userspace - case in point, -a program run with "ulimit -S -v 20000" failed when the 1MB gap was -counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK -and strict non-overcommit mode. - -Instead of keeping gap inside the stack vma, maintain the stack guard -gap as a gap between vmas: using vm_start_gap() in place of vm_start -(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few -places which need to respect the gap - mainly arch_get_unmapped_area(), -and and the vma tree's subtree_gap support for that. - -Original-patch-by: Oleg Nesterov <oleg@redhat.com> -Original-patch-by: Michal Hocko <mhocko@suse.com> -Signed-off-by: Hugh Dickins <hughd@google.com> -Acked-by: Michal Hocko <mhocko@suse.com> -Tested-by: Helge Deller <deller@gmx.de> # parisc -Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> -[wt: backport to 4.11: adjust context] -[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide] -Signed-off-by: Willy Tarreau <w@1wt.eu> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - Documentation/kernel-parameters.txt | 7 + - arch/arc/mm/mmap.c | 2 - arch/arm/mm/mmap.c | 4 - arch/frv/mm/elf-fdpic.c | 2 - arch/mips/mm/mmap.c | 2 - arch/parisc/kernel/sys_parisc.c | 15 ++- - arch/powerpc/mm/hugetlbpage-radix.c | 2 - arch/powerpc/mm/mmap.c | 4 - arch/powerpc/mm/slice.c | 2 - arch/s390/mm/mmap.c | 4 - arch/sh/mm/mmap.c | 4 - arch/sparc/kernel/sys_sparc_64.c | 4 - arch/sparc/mm/hugetlbpage.c | 2 - arch/tile/mm/hugetlbpage.c | 2 - arch/x86/kernel/sys_x86_64.c | 4 - arch/x86/mm/hugetlbpage.c | 2 - arch/xtensa/kernel/syscall.c | 2 - fs/hugetlbfs/inode.c | 2 - fs/proc/task_mmu.c | 4 - include/linux/mm.h | 53 ++++++------ - mm/gup.c | 5 - - mm/memory.c | 38 --------- - mm/mmap.c | 149 +++++++++++++++++++++--------------- - 23 files changed, 152 insertions(+), 163 deletions(-) - ---- a/Documentation/kernel-parameters.txt -+++ b/Documentation/kernel-parameters.txt -@@ -3932,6 +3932,13 @@ bytes respectively. Such letter suffixes - spia_pedr= - spia_peddr= - -+ stack_guard_gap= [MM] -+ override the default stack gap protection. The value -+ is in page units and it defines how many pages prior -+ to (for stacks growing down) resp. after (for stacks -+ growing up) the main stack are reserved for no other -+ mapping. Default value is 256 pages. -+ - stacktrace [FTRACE] - Enabled the stack tracer on boot up. - ---- a/arch/arc/mm/mmap.c -+++ b/arch/arc/mm/mmap.c -@@ -64,7 +64,7 @@ arch_get_unmapped_area(struct file *filp - - 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; - } - ---- a/arch/arm/mm/mmap.c -+++ b/arch/arm/mm/mmap.c -@@ -89,7 +89,7 @@ arch_get_unmapped_area(struct file *filp - - 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; - } - -@@ -140,7 +140,7 @@ arch_get_unmapped_area_topdown(struct fi - 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; - } - ---- a/arch/frv/mm/elf-fdpic.c -+++ b/arch/frv/mm/elf-fdpic.c -@@ -74,7 +74,7 @@ unsigned long arch_get_unmapped_area(str - addr = PAGE_ALIGN(addr); - vma = find_vma(current->mm, addr); - if (TASK_SIZE - len >= addr && -- (!vma || addr + len <= vma->vm_start)) -+ (!vma || addr + len <= vm_start_gap(vma))) - goto success; - } - ---- a/arch/mips/mm/mmap.c -+++ b/arch/mips/mm/mmap.c -@@ -92,7 +92,7 @@ static unsigned long arch_get_unmapped_a - - 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; - } - ---- a/arch/parisc/kernel/sys_parisc.c -+++ b/arch/parisc/kernel/sys_parisc.c -@@ -88,7 +88,7 @@ unsigned long arch_get_unmapped_area(str - unsigned long len, unsigned long pgoff, unsigned long flags) - { - struct mm_struct *mm = current->mm; -- struct vm_area_struct *vma; -+ struct vm_area_struct *vma, *prev; - unsigned long task_size = TASK_SIZE; - int do_color_align, last_mmap; - struct vm_unmapped_area_info info; -@@ -115,9 +115,10 @@ unsigned long arch_get_unmapped_area(str - else - addr = PAGE_ALIGN(addr); - -- vma = find_vma(mm, addr); -+ vma = find_vma_prev(mm, addr, &prev); - if (task_size - len >= addr && -- (!vma || addr + len <= vma->vm_start)) -+ (!vma || addr + len <= vm_start_gap(vma)) && -+ (!prev || addr >= vm_end_gap(prev))) - goto found_addr; - } - -@@ -141,7 +142,7 @@ arch_get_unmapped_area_topdown(struct fi - 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; - int do_color_align, last_mmap; -@@ -175,9 +176,11 @@ arch_get_unmapped_area_topdown(struct fi - addr = COLOR_ALIGN(addr, last_mmap, pgoff); - else - addr = PAGE_ALIGN(addr); -- vma = find_vma(mm, addr); -+ -+ vma = find_vma_prev(mm, addr, &prev); - if (TASK_SIZE - len >= addr && -- (!vma || addr + len <= vma->vm_start)) -+ (!vma || addr + len <= vm_start_gap(vma)) && -+ (!prev || addr >= vm_end_gap(prev))) - goto found_addr; - } - ---- a/arch/powerpc/mm/hugetlbpage-radix.c -+++ b/arch/powerpc/mm/hugetlbpage-radix.c -@@ -65,7 +65,7 @@ radix__hugetlb_get_unmapped_area(struct - 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; - } - /* ---- a/arch/powerpc/mm/mmap.c -+++ b/arch/powerpc/mm/mmap.c -@@ -106,7 +106,7 @@ radix__arch_get_unmapped_area(struct fil - addr = PAGE_ALIGN(addr); - vma = find_vma(mm, addr); - if (TASK_SIZE - len >= addr && addr >= mmap_min_addr && -- (!vma || addr + len <= vma->vm_start)) -+ (!vma || addr + len <= vm_start_gap(vma))) - return addr; - } - -@@ -142,7 +142,7 @@ radix__arch_get_unmapped_area_topdown(st - addr = PAGE_ALIGN(addr); - vma = find_vma(mm, addr); - if (TASK_SIZE - len >= addr && addr >= mmap_min_addr && -- (!vma || addr + len <= vma->vm_start)) -+ (!vma || addr + len <= vm_start_gap(vma))) - return addr; - } - ---- a/arch/powerpc/mm/slice.c -+++ b/arch/powerpc/mm/slice.c -@@ -105,7 +105,7 @@ static int slice_area_is_free(struct mm_ - 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) ---- a/arch/s390/mm/mmap.c -+++ b/arch/s390/mm/mmap.c -@@ -98,7 +98,7 @@ arch_get_unmapped_area(struct file *filp - addr = PAGE_ALIGN(addr); - vma = find_vma(mm, addr); - if (TASK_SIZE - len >= addr && addr >= mmap_min_addr && -- (!vma || addr + len <= vma->vm_start)) -+ (!vma || addr + len <= vm_start_gap(vma))) - return addr; - } - -@@ -136,7 +136,7 @@ arch_get_unmapped_area_topdown(struct fi - addr = PAGE_ALIGN(addr); - vma = find_vma(mm, addr); - if (TASK_SIZE - len >= addr && addr >= mmap_min_addr && -- (!vma || addr + len <= vma->vm_start)) -+ (!vma || addr + len <= vm_start_gap(vma))) - return addr; - } - ---- a/arch/sh/mm/mmap.c -+++ b/arch/sh/mm/mmap.c -@@ -63,7 +63,7 @@ unsigned long arch_get_unmapped_area(str - - 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; - } - -@@ -113,7 +113,7 @@ arch_get_unmapped_area_topdown(struct fi - - 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; - } - ---- a/arch/sparc/kernel/sys_sparc_64.c -+++ b/arch/sparc/kernel/sys_sparc_64.c -@@ -118,7 +118,7 @@ unsigned long arch_get_unmapped_area(str - - 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; - } - -@@ -181,7 +181,7 @@ arch_get_unmapped_area_topdown(struct fi - - 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; - } - ---- a/arch/sparc/mm/hugetlbpage.c -+++ b/arch/sparc/mm/hugetlbpage.c -@@ -116,7 +116,7 @@ hugetlb_get_unmapped_area(struct file *f - 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) ---- a/arch/tile/mm/hugetlbpage.c -+++ b/arch/tile/mm/hugetlbpage.c -@@ -232,7 +232,7 @@ unsigned long hugetlb_get_unmapped_area( - 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) ---- a/arch/x86/kernel/sys_x86_64.c -+++ b/arch/x86/kernel/sys_x86_64.c -@@ -140,7 +140,7 @@ arch_get_unmapped_area(struct file *filp - 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; - } - -@@ -183,7 +183,7 @@ arch_get_unmapped_area_topdown(struct fi - 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; - } - ---- a/arch/x86/mm/hugetlbpage.c -+++ b/arch/x86/mm/hugetlbpage.c -@@ -144,7 +144,7 @@ hugetlb_get_unmapped_area(struct file *f - 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) ---- a/arch/xtensa/kernel/syscall.c -+++ b/arch/xtensa/kernel/syscall.c -@@ -87,7 +87,7 @@ unsigned long arch_get_unmapped_area(str - /* At this point: (!vmm || addr < vmm->vm_end). */ - if (TASK_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) ---- a/fs/hugetlbfs/inode.c -+++ b/fs/hugetlbfs/inode.c -@@ -191,7 +191,7 @@ hugetlb_get_unmapped_area(struct file *f - 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; - } - ---- a/fs/proc/task_mmu.c -+++ b/fs/proc/task_mmu.c -@@ -299,11 +299,7 @@ show_map_vma(struct seq_file *m, struct - - /* 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_setwidth(m, 25 + sizeof(void *) * 6 - 1); - seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", ---- a/include/linux/mm.h -+++ b/include/linux/mm.h -@@ -1356,39 +1356,11 @@ int clear_page_dirty_for_io(struct page - - int get_cmdline(struct task_struct *task, char *buffer, int buflen); - --/* 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 bool vma_is_anonymous(struct vm_area_struct *vma) - { - return !vma->vm_ops; - } - --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); --} -- - int vma_is_stack_for_current(struct vm_area_struct *vma); - - extern unsigned long move_page_tables(struct vm_area_struct *vma, -@@ -2127,6 +2099,7 @@ void page_cache_async_readahead(struct a - pgoff_t offset, - unsigned long size); - -+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); - -@@ -2155,6 +2128,30 @@ static inline struct vm_area_struct * fi - 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; ---- a/mm/gup.c -+++ b/mm/gup.c -@@ -370,11 +370,6 @@ static int faultin_page(struct task_stru - /* mlock all present pages, but do not fault in new pages */ - if ((*flags & (FOLL_POPULATE | FOLL_MLOCK)) == FOLL_MLOCK) - return -ENOENT; -- /* For mm_populate(), just skip the stack guard page. */ -- if ((*flags & FOLL_POPULATE) && -- (stack_guard_page_start(vma, address) || -- stack_guard_page_end(vma, address + PAGE_SIZE))) -- return -ENOENT; - if (*flags & FOLL_WRITE) - fault_flags |= FAULT_FLAG_WRITE; - if (*flags & FOLL_REMOTE) ---- a/mm/memory.c -+++ b/mm/memory.c -@@ -2699,40 +2699,6 @@ 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. -@@ -2748,10 +2714,6 @@ static int do_anonymous_page(struct faul - 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, fe->address) < 0) -- return VM_FAULT_SIGSEGV; -- - /* - * Use pte_alloc() instead of pte_alloc_map(). We can't run - * pte_offset_map() on pmds where a huge pmd might be created ---- a/mm/mmap.c -+++ b/mm/mmap.c -@@ -183,6 +183,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) - unsigned long retval; - unsigned long newbrk, oldbrk; - struct mm_struct *mm = current->mm; -+ struct vm_area_struct *next; - unsigned long min_brk; - bool populate; - -@@ -228,7 +229,8 @@ 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. */ -@@ -251,10 +253,22 @@ out: - - static long vma_compute_subtree_gap(struct vm_area_struct *vma) - { -- unsigned long max, subtree_gap; -- max = vma->vm_start; -- if (vma->vm_prev) -- max -= vma->vm_prev->vm_end; -+ unsigned long max, prev_end, subtree_gap; -+ -+ /* -+ * Note: in the rare case of a VM_GROWSDOWN above a VM_GROWSUP, we -+ * allow two stack_guard_gaps between them here, and when choosing -+ * an unmapped area; whereas when expanding we only require one. -+ * That's a little inconsistent, but keeps the code here simpler. -+ */ -+ max = vm_start_gap(vma); -+ if (vma->vm_prev) { -+ prev_end = vm_end_gap(vma->vm_prev); -+ if (max > prev_end) -+ max -= prev_end; -+ else -+ max = 0; -+ } - if (vma->vm_rb.rb_left) { - subtree_gap = rb_entry(vma->vm_rb.rb_left, - struct vm_area_struct, vm_rb)->rb_subtree_gap; -@@ -350,7 +364,7 @@ static void validate_mm(struct mm_struct - anon_vma_unlock_read(anon_vma); - } - -- highest_address = vma->vm_end; -+ highest_address = vm_end_gap(vma); - vma = vma->vm_next; - i++; - } -@@ -539,7 +553,7 @@ void __vma_link_rb(struct mm_struct *mm, - if (vma->vm_next) - vma_gap_update(vma->vm_next); - else -- mm->highest_vm_end = vma->vm_end; -+ mm->highest_vm_end = vm_end_gap(vma); - - /* - * vma->vm_prev wasn't known when we followed the rbtree to find the -@@ -854,7 +868,7 @@ again: - vma_gap_update(vma); - if (end_changed) { - if (!next) -- mm->highest_vm_end = end; -+ mm->highest_vm_end = vm_end_gap(vma); - else if (!adjust_next) - vma_gap_update(next); - } -@@ -939,7 +953,7 @@ again: - * mm->highest_vm_end doesn't need any update - * in remove_next == 1 case. - */ -- VM_WARN_ON(mm->highest_vm_end != end); -+ VM_WARN_ON(mm->highest_vm_end != vm_end_gap(vma)); - } - } - if (insert && file) -@@ -1783,7 +1797,7 @@ unsigned long unmapped_area(struct vm_un - - while (true) { - /* Visit left subtree if it looks promising */ -- gap_end = vma->vm_start; -+ gap_end = vm_start_gap(vma); - if (gap_end >= low_limit && vma->vm_rb.rb_left) { - struct vm_area_struct *left = - rb_entry(vma->vm_rb.rb_left, -@@ -1794,7 +1808,7 @@ unsigned long unmapped_area(struct vm_un - } - } - -- gap_start = vma->vm_prev ? vma->vm_prev->vm_end : 0; -+ gap_start = vma->vm_prev ? vm_end_gap(vma->vm_prev) : 0; - check_current: - /* Check if current node has a suitable gap */ - if (gap_start > high_limit) -@@ -1821,8 +1835,8 @@ check_current: - vma = rb_entry(rb_parent(prev), - struct vm_area_struct, vm_rb); - if (prev == vma->vm_rb.rb_left) { -- gap_start = vma->vm_prev->vm_end; -- gap_end = vma->vm_start; -+ gap_start = vm_end_gap(vma->vm_prev); -+ gap_end = vm_start_gap(vma); - goto check_current; - } - } -@@ -1886,7 +1900,7 @@ unsigned long unmapped_area_topdown(stru - - while (true) { - /* Visit right subtree if it looks promising */ -- gap_start = vma->vm_prev ? vma->vm_prev->vm_end : 0; -+ gap_start = vma->vm_prev ? vm_end_gap(vma->vm_prev) : 0; - if (gap_start <= high_limit && vma->vm_rb.rb_right) { - struct vm_area_struct *right = - rb_entry(vma->vm_rb.rb_right, -@@ -1899,7 +1913,7 @@ unsigned long unmapped_area_topdown(stru - - check_current: - /* Check if current node has a suitable gap */ -- gap_end = vma->vm_start; -+ gap_end = vm_start_gap(vma); - if (gap_end < low_limit) - return -ENOMEM; - if (gap_start <= high_limit && gap_end - gap_start >= length) -@@ -1925,7 +1939,7 @@ check_current: - struct vm_area_struct, vm_rb); - if (prev == vma->vm_rb.rb_right) { - gap_start = vma->vm_prev ? -- vma->vm_prev->vm_end : 0; -+ vm_end_gap(vma->vm_prev) : 0; - goto check_current; - } - } -@@ -1963,7 +1977,7 @@ arch_get_unmapped_area(struct file *filp - unsigned long len, unsigned long pgoff, unsigned long flags) - { - struct mm_struct *mm = current->mm; -- struct vm_area_struct *vma; -+ struct vm_area_struct *vma, *prev; - struct vm_unmapped_area_info info; - - if (len > TASK_SIZE - mmap_min_addr) -@@ -1974,9 +1988,10 @@ arch_get_unmapped_area(struct file *filp - - 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; - } - -@@ -1999,7 +2014,7 @@ arch_get_unmapped_area_topdown(struct fi - 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; - struct vm_unmapped_area_info info; -@@ -2014,9 +2029,10 @@ arch_get_unmapped_area_topdown(struct fi - /* 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; - } - -@@ -2151,21 +2167,19 @@ find_vma_prev(struct mm_struct *mm, unsi - * 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, vma->vm_flags, 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 > READ_ONCE(rlim[RLIMIT_STACK].rlim_cur)) -+ if (size > READ_ONCE(rlim[RLIMIT_STACK].rlim_cur)) - return -ENOMEM; - - /* mlock limit tests */ -@@ -2203,17 +2217,30 @@ static int acct_stack_growth(struct vm_a - int expand_upwards(struct vm_area_struct *vma, unsigned long address) - { - struct mm_struct *mm = vma->vm_mm; -+ struct vm_area_struct *next; -+ unsigned long gap_addr; - int error = 0; - - if (!(vma->vm_flags & VM_GROWSUP)) - return -EFAULT; - - /* Guard against wrapping around to address 0. */ -- if (address < PAGE_ALIGN(address+4)) -- address = PAGE_ALIGN(address+4); -- else -+ 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; -@@ -2257,7 +2284,7 @@ int expand_upwards(struct vm_area_struct - if (vma->vm_next) - vma_gap_update(vma->vm_next); - else -- mm->highest_vm_end = address; -+ mm->highest_vm_end = vm_end_gap(vma); - spin_unlock(&mm->page_table_lock); - - perf_event_mmap(vma); -@@ -2278,6 +2305,8 @@ int expand_downwards(struct vm_area_stru - unsigned long address) - { - struct mm_struct *mm = vma->vm_mm; -+ struct vm_area_struct *prev; -+ unsigned long gap_addr; - int error; - - address &= PAGE_MASK; -@@ -2285,6 +2314,17 @@ int expand_downwards(struct vm_area_stru - if (error) - return error; - -+ /* 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; -@@ -2339,28 +2379,25 @@ int expand_downwards(struct vm_area_stru - 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); - } - -@@ -2382,14 +2419,6 @@ find_extend_vma(struct mm_struct *mm, un - #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); - } - -@@ -2487,7 +2516,7 @@ detach_vmas_to_be_unmapped(struct mm_str - vma->vm_prev = prev; - vma_gap_update(vma); - } else -- mm->highest_vm_end = prev ? prev->vm_end : 0; -+ mm->highest_vm_end = prev ? vm_end_gap(prev) : 0; - tail_vma->vm_next = NULL; - - /* Kill the cache */ |