From: Alexandre Ghiti <alex@ghiti.fr>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Ralf Baechle <ralf@linux-mips.org>,
Paul Burton <paul.burton@mips.com>,
James Hogan <jhogan@kernel.org>,
Palmer Dabbelt <palmer@sifive.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Luis Chamberlain <mcgrof@kernel.org>,
Kees Cook <keescook@chromium.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, Alexandre Ghiti <alex@ghiti.fr>
Subject: [PATCH v2 4/5] mips: Use generic mmap top-down layout
Date: Thu, 4 Apr 2019 01:51:27 -0400 [thread overview]
Message-ID: <20190404055128.24330-5-alex@ghiti.fr> (raw)
In-Reply-To: <20190404055128.24330-1-alex@ghiti.fr>
mips uses a top-down layout by default that fits the generic functions.
At the same time, this commit allows to fix problem uncovered
and not fixed for mips here:
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1429066.html
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
---
arch/mips/Kconfig | 1 +
arch/mips/include/asm/processor.h | 5 ---
arch/mips/mm/mmap.c | 57 -------------------------------
3 files changed, 1 insertion(+), 62 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4a5f5b0ee9a9..c21aa6371eab 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -14,6 +14,7 @@ config MIPS
select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
+ select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
select ARCH_WANT_IPC_PARSE_VERSION
select BUILDTIME_EXTABLE_SORT
select CLONE_BACKWARDS
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index aca909bd7841..fba18d4a9190 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -29,11 +29,6 @@
extern unsigned int vced_count, vcei_count;
-/*
- * MIPS does have an arch_pick_mmap_layout()
- */
-#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
-
#ifdef CONFIG_32BIT
#ifdef CONFIG_KVM_GUEST
/* User space process size is limited to 1GB in KVM Guest Mode */
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index 2f616ebeb7e0..61e65a69bb09 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
@@ -20,33 +20,6 @@
unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
EXPORT_SYMBOL(shm_align_mask);
-/* gap between mmap and stack */
-#define MIN_GAP (128*1024*1024UL)
-#define MAX_GAP ((TASK_SIZE)/6*5)
-
-static int mmap_is_legacy(struct rlimit *rlim_stack)
-{
- if (current->personality & ADDR_COMPAT_LAYOUT)
- return 1;
-
- if (rlim_stack->rlim_cur == RLIM_INFINITY)
- return 1;
-
- return sysctl_legacy_va_layout;
-}
-
-static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack)
-{
- unsigned long gap = rlim_stack->rlim_cur;
-
- if (gap < MIN_GAP)
- gap = MIN_GAP;
- else if (gap > MAX_GAP)
- gap = MAX_GAP;
-
- return PAGE_ALIGN(TASK_SIZE - gap - rnd);
-}
-
#define COLOUR_ALIGN(addr, pgoff) \
((((addr) + shm_align_mask) & ~shm_align_mask) + \
(((pgoff) << PAGE_SHIFT) & shm_align_mask))
@@ -144,36 +117,6 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
addr0, len, pgoff, flags, DOWN);
}
-unsigned long arch_mmap_rnd(void)
-{
- unsigned long rnd;
-
-#ifdef CONFIG_COMPAT
- if (TASK_IS_32BIT_ADDR)
- rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1);
- else
-#endif /* CONFIG_COMPAT */
- rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1);
-
- return rnd << PAGE_SHIFT;
-}
-
-void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
-{
- unsigned long random_factor = 0UL;
-
- if (current->flags & PF_RANDOMIZE)
- random_factor = arch_mmap_rnd();
-
- if (mmap_is_legacy(rlim_stack)) {
- mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
- mm->get_unmapped_area = arch_get_unmapped_area;
- } else {
- mm->mmap_base = mmap_base(random_factor, rlim_stack);
- mm->get_unmapped_area = arch_get_unmapped_area_topdown;
- }
-}
-
static inline unsigned long brk_rnd(void)
{
unsigned long rnd = get_random_long();
--
2.20.1
next prev parent reply other threads:[~2019-04-04 5:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 5:51 [PATCH v2 0/5] Provide generic top-down mmap layout functions Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 1/5] mm, fs: Move randomize_stack_top from fs to mm Alexandre Ghiti
2019-04-10 6:54 ` Christoph Hellwig
2019-04-10 7:18 ` Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 2/5] arm64, mm: Move generic mmap layout functions " Alexandre Ghiti
2019-04-10 6:59 ` Christoph Hellwig
2019-04-10 7:32 ` Alexandre Ghiti
2019-04-10 18:27 ` Kees Cook
2019-04-11 7:16 ` Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 3/5] arm: Use generic mmap top-down layout Alexandre Ghiti
2019-04-04 5:51 ` Alexandre Ghiti [this message]
2019-04-04 5:51 ` [PATCH v2 5/5] riscv: Make mmap allocation top-down by default Alexandre Ghiti
2019-04-10 6:59 ` Christoph Hellwig
2019-04-10 7:18 ` Alexandre Ghiti
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