From: Dmitry Safonov <dsafonov@virtuozzo.com>
To: <linux-kernel@vger.kernel.org>
Cc: <0x7f454c46@gmail.com>, Dmitry Safonov <dsafonov@virtuozzo.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
<x86@kernel.org>, <linux-mm@kvack.org>
Subject: [PATCHv4 1/5] x86/mm: split arch_mmap_rnd() on compat/native versions
Date: Mon, 30 Jan 2017 15:04:28 +0300 [thread overview]
Message-ID: <20170130120432.6716-2-dsafonov@virtuozzo.com> (raw)
In-Reply-To: <20170130120432.6716-1-dsafonov@virtuozzo.com>
I need those arch_{native,compat}_rnd() to compute separately
random factor for mmap() in compat syscalls for 64-bit binaries
and vice-versa for native syscall in 32-bit compat binaries.
They will be used in the following patches.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
---
arch/x86/mm/mmap.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index d2dc0438d654..42063e787717 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -65,20 +65,27 @@ static int mmap_is_legacy(void)
return sysctl_legacy_va_layout;
}
-unsigned long arch_mmap_rnd(void)
+#ifdef CONFIG_COMPAT
+static unsigned long arch_compat_rnd(void)
{
- unsigned long rnd;
+ return (get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1))
+ << PAGE_SHIFT;
+}
+#endif
- if (mmap_is_ia32())
+static unsigned long arch_native_rnd(void)
+{
+ return (get_random_long() & ((1UL << mmap_rnd_bits) - 1)) << PAGE_SHIFT;
+}
+
+unsigned long arch_mmap_rnd(void)
+{
#ifdef CONFIG_COMPAT
- rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1);
-#else
- rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1);
+ if (mmap_is_ia32())
+ return arch_compat_rnd();
#endif
- else
- rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1);
- return rnd << PAGE_SHIFT;
+ return arch_native_rnd();
}
static unsigned long mmap_base(unsigned long rnd)
--
2.11.0
next prev parent reply other threads:[~2017-01-30 12:05 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-30 12:04 [PATCHv4 0/5] Fix compatible mmap() return pointer over 4Gb Dmitry Safonov
2017-01-30 12:04 ` Dmitry Safonov [this message]
2017-02-09 13:55 ` [PATCHv4 1/5] x86/mm: split arch_mmap_rnd() on compat/native versions Borislav Petkov
2017-02-09 23:06 ` Andy Lutomirski
2017-02-10 20:10 ` Thomas Gleixner
2017-02-10 20:25 ` Borislav Petkov
2017-02-10 21:28 ` Dmitry Safonov
2017-02-11 8:23 ` Thomas Gleixner
2017-02-13 11:12 ` Dmitry Safonov
2017-02-13 11:22 ` Thomas Gleixner
2017-01-30 12:04 ` [PATCHv4 2/5] x86/mm: introduce mmap{,_legacy}_base Dmitry Safonov
2017-02-11 14:13 ` Thomas Gleixner
2017-02-13 13:02 ` Dmitry Safonov
2017-02-13 13:13 ` Thomas Gleixner
2017-02-13 14:37 ` Dmitry Safonov
2017-02-13 15:35 ` Thomas Gleixner
2017-01-30 12:04 ` [PATCHv4 3/5] x86/mm: fix 32-bit mmap() for 64-bit ELF Dmitry Safonov
2017-02-11 19:49 ` Thomas Gleixner
2017-02-14 15:24 ` Dmitry Safonov
2017-01-30 12:04 ` [PATCHv4 4/5] x86/mm: check in_compat_syscall() instead TIF_ADDR32 for mmap(MAP_32BIT) Dmitry Safonov
2017-02-11 20:13 ` Thomas Gleixner
2017-02-14 16:11 ` Dmitry Safonov
2017-02-14 16:14 ` Dmitry Safonov
2017-01-30 12:04 ` [PATCHv4 5/5] selftests/x86: add test to check compat mmap() return addr Dmitry Safonov
2017-02-06 16:46 ` [PATCHv4 0/5] Fix compatible mmap() return pointer over 4Gb Dmitry Safonov
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