Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-mm@kvack.org, linux-arch@vger.kernel.org,
	linux-api@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	Andy Lutomirski <luto@amacapital.net>,
	Balbir Singh <bsingharora@gmail.com>,
	Borislav Petkov <bp@alien8.de>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Eugene Syromiatnikov <esyr@redhat.com>,
	Florian Weimer <fweimer@redhat.com>,
	"H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Kees Cook <keescook@chromium.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Nadav Amit <nadav.amit@gmail.com>,
	Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>,
	Peter Zijlstra <peterz@infradead.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
	Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>,
	Dave Martin <Dave.Martin@arm.com>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v8 04/14] mm/mmap: Add IBT bitmap size to address space limit check
Date: Tue, 13 Aug 2019 13:53:49 -0700
Message-ID: <20190813205359.12196-5-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20190813205359.12196-1-yu-cheng.yu@intel.com>

The indirect branch tracking legacy bitmap takes a large address
space.  This causes may_expand_vm() failure on the address limit
check.  For a IBT-enabled task, add the bitmap size to the
address limit.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
 arch/x86/include/asm/mmu_context.h | 10 ++++++++++
 mm/mmap.c                          | 19 ++++++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index a9a768529540..e18e89ef332d 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -360,6 +360,16 @@ static inline unsigned long __get_current_cr3_fast(void)
 	return cr3;
 }
 
+#ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER
+static inline unsigned long arch_as_limit(void)
+{
+	if (current->thread.cet.ibt_enabled)
+		return IBT_BITMAP_SIZE;
+	else
+		return 0;
+}
+#endif
+
 typedef struct {
 	struct mm_struct *mm;
 } temp_mm_state_t;
diff --git a/mm/mmap.c b/mm/mmap.c
index 1acded00f003..1bfd9aec9aed 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3283,13 +3283,30 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
 	return NULL;
 }
 
+#ifndef CONFIG_ARCH_HAS_AS_LIMIT
+static inline unsigned long arch_as_limit(void)
+{
+	return 0;
+}
+#endif
+
 /*
  * Return true if the calling process may expand its vm space by the passed
  * number of pages
  */
 bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages)
 {
-	if (mm->total_vm + npages > rlimit(RLIMIT_AS) >> PAGE_SHIFT)
+	unsigned long as_limit = rlimit(RLIMIT_AS);
+	unsigned long as_limit_plus = as_limit + arch_as_limit();
+
+	/* as_limit_plus overflowed */
+	if (as_limit_plus < as_limit)
+		as_limit_plus = RLIM_INFINITY;
+
+	if (as_limit_plus > as_limit)
+		as_limit = as_limit_plus;
+
+	if (mm->total_vm + npages > as_limit >> PAGE_SHIFT)
 		return false;
 
 	if (is_data_mapping(flags) &&
-- 
2.17.1



  parent reply index

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-13 20:53 [PATCH v8 00/14] Control-flow Enforcement: Branch Tracking, PTRACE Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 01/14] x86/cet/ibt: Add Kconfig option for user-mode Indirect Branch Tracking Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 02/14] x86/cet/ibt: User-mode indirect branch tracking support Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 03/14] x86/cet/ibt: Handle signals for end branch Yu-cheng Yu
2019-08-13 20:53 ` Yu-cheng Yu [this message]
2019-08-13 20:53 ` [PATCH v8 05/14] x86/cet/ibt: ELF header parsing for IBT Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 06/14] x86/cet/ibt: Add arch_prctl functions " Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 07/14] x86/cet/ibt: Add ENDBR to op-code-map Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 08/14] x86/vdso: Insert endbr32/endbr64 to vDSO Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 09/14] x86/vdso/32: Add ENDBR32 to __kernel_vsyscall entry point Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 10/14] x86/vsyscall/64: Add ENDBR64 to vsyscall entry points Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 11/14] x86/vsyscall/64: Fixup shadow stack and branch tracking for vsyscall Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 12/14] x86/cet: Add PTRACE interface for CET Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 13/14] x86: Discard .note.gnu.property sections Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 14/14] Introduce arch_prctl(ARCH_X86_CET_MARK_LEGACY_CODE) Yu-cheng Yu

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190813205359.12196-5-yu-cheng.yu@intel.com \
    --to=yu-cheng.yu@intel.com \
    --cc=Dave.Martin@arm.com \
    --cc=arnd@arndb.de \
    --cc=bp@alien8.de \
    --cc=bsingharora@gmail.com \
    --cc=corbet@lwn.net \
    --cc=dave.hansen@linux.intel.com \
    --cc=esyr@redhat.com \
    --cc=fweimer@redhat.com \
    --cc=gorcunov@gmail.com \
    --cc=hjl.tools@gmail.com \
    --cc=hpa@zytor.com \
    --cc=jannh@google.com \
    --cc=keescook@chromium.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@amacapital.net \
    --cc=mike.kravetz@oracle.com \
    --cc=mingo@redhat.com \
    --cc=nadav.amit@gmail.com \
    --cc=oleg@redhat.com \
    --cc=pavel@ucw.cz \
    --cc=peterz@infradead.org \
    --cc=ravi.v.shankar@intel.com \
    --cc=rdunlap@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=vedvyas.shanbhogue@intel.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org linux-mm@archiver.kernel.org
	public-inbox-index linux-mm


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox