From: Helge Deller <deller@xxxxxx>
parisc uses a top-down layout by default that exactly fits the generic
functions, so get rid of arch specific code and use the generic version
by selecting ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT.
Note that on parisc the stack always grows up and a "unlimited stack"
simply means that the value as defined in CONFIG_STACK_MAX_DEFAULT_SIZE_MB
should be used. So RLIM_INFINITY is not an indicator to use the legacy
memory layout.
Signed-off-by: Helge Deller <deller@xxxxxx>
---
arch/parisc/Kconfig | 17 +++++++++++
arch/parisc/kernel/process.c | 14 ---------
arch/parisc/kernel/sys_parisc.c | 54 +--------------------------------
mm/util.c | 5 ++-
4 files changed, 22 insertions(+), 68 deletions(-)
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 4cb46d5c64a2..3a257bca0878 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -49,6 +49,9 @@ config PARISC
select TTY # Needed for pdc_cons.c
select HAS_IOPORT if PCI || EISA
select HAVE_DEBUG_STACKOVERFLOW
+ select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
+ select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
+ select HAVE_ARCH_MMAP_RND_BITS
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HASH
select HAVE_ARCH_JUMP_LABEL
@@ -124,6 +127,20 @@ config TIME_LOW_RES
depends on SMP
default y
+config ARCH_MMAP_RND_BITS_MIN
+ default 18 if 64BIT
+ default 8
+
+config ARCH_MMAP_RND_COMPAT_BITS_MIN
+ default 8
+
+config ARCH_MMAP_RND_BITS_MAX
+ default 24 if 64BIT
+ default 17
+
+config ARCH_MMAP_RND_COMPAT_BITS_MAX
+ default 17
+
# unless you want to implement ACPI on PA-RISC ... ;-)
config PM
bool
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 62f9b14c6406..ed93bd8c1545 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -278,17 +278,3 @@ __get_wchan(struct task_struct *p)
} while (count++ < MAX_UNWIND_ENTRIES);
return 0;
}
-
-static inline unsigned long brk_rnd(void)
-{
- return (get_random_u32() & BRK_RND_MASK) << PAGE_SHIFT;
-}
-
-unsigned long arch_randomize_brk(struct mm_struct *mm)
-{
- unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
-
- if (ret < mm->brk)
- return mm->brk;
- return ret;
-}
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 9915062d5243..ab896eff7a1d 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -161,7 +161,7 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
}
info.flags = 0;
- info.low_limit = mm->mmap_legacy_base;
+ info.low_limit = mm->mmap_base;
info.high_limit = mmap_upper_limit(NULL);
return vm_unmapped_area(&info);
}
@@ -181,58 +181,6 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
addr, len, pgoff, flags, DOWN);
}
-static int mmap_is_legacy(void)
-{
- if (current->personality & ADDR_COMPAT_LAYOUT)
- return 1;
-
- /* parisc stack always grows up - so a unlimited stack should
- * not be an indicator to use the legacy memory layout.
- * if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
- * return 1;
- */
-
- return sysctl_legacy_va_layout;
-}
-
-static unsigned long mmap_rnd(void)
-{
- unsigned long rnd = 0;
-
- if (current->flags & PF_RANDOMIZE)
- rnd = get_random_u32() & MMAP_RND_MASK;
-
- return rnd << PAGE_SHIFT;
-}
-
-unsigned long arch_mmap_rnd(void)
-{
- return (get_random_u32() & MMAP_RND_MASK) << PAGE_SHIFT;
-}
-
-static unsigned long mmap_legacy_base(void)
-{
- return TASK_UNMAPPED_BASE + mmap_rnd();
-}
-
-/*
- * This function, called very early during the creation of a new
- * process VM image, sets up which VM layout function to use:
- */
-void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
-{
- mm->mmap_legacy_base = mmap_legacy_base();
- mm->mmap_base = mmap_upper_limit(rlim_stack);
-
- if (mmap_is_legacy()) {
- mm->mmap_base = mm->mmap_legacy_base;
- mm->get_unmapped_area = arch_get_unmapped_area;
- } else {
- mm->get_unmapped_area = arch_get_unmapped_area_topdown;
- }
-}
-
-
asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags, unsigned long fd,
unsigned long pgoff)
diff --git a/mm/util.c b/mm/util.c
index dd12b9531ac4..881020644497 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -396,7 +396,10 @@ static int mmap_is_legacy(struct rlimit *rlim_stack)
if (current->personality & ADDR_COMPAT_LAYOUT)
return 1;
- if (rlim_stack->rlim_cur == RLIM_INFINITY)
+ /* On parisc the stack always grows up - so a unlimited stack should
+ * not be an indicator to use the legacy memory layout. */
+ if (rlim_stack->rlim_cur == RLIM_INFINITY &&
+ !IS_ENABLED(CONFIG_STACK_GROWSUP))
return 1;
return sysctl_legacy_va_layout;
--
2.41.0
