From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org,
Anshuman Khandual <khandual@linux.vnet.ibm.com>,
Rick Lindsley <ricklind@linux.vnet.ibm.com>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [PATCH] powerpc/mm: Update mm context addr limit correctly.
Date: Tue, 11 Apr 2017 19:45:35 +0530 [thread overview]
Message-ID: <1491920135-13612-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw)
We added the addr < TASK_SIZE check to avoid updating addr_limit unnecessarily and
also to avoid calling slice_flush_segments on all the cpus. This had the side
effect of having different behaviour when using an addr value above TASK_SIZE
before updating addr_limit and after updating addr_limit as show by below
output:
requesting with hint 0x0
Addr returned 0x7fff893a0000
requesting with hint 0xffffffffffffffff
Addr returned 0x7fff891b0000 <===== 1st return
requesting with hint 0x1000000000000
Addr returned 0x1000000000000
requesting with hint 0xffffffffffffffff
Addr returned 0x1ffff89410000 <==== second return
After fix:
requesting with hint 0x0
Addr returned 0x7fff8bc00000
requesting with hint 0xffffffffffffffff
Addr returned 0x1ffff8bc80000 <==== 1st return
requesting with hint 0x1000000000000
Addr returned 0x1000000000000
requesting with hint 0xffffffffffffffff
Addr returned 0x1ffff8bc60000 <==== second return
Fixes: 1b49451ebd3e9 (powerpc/mm: Enable mappings above 128TB)
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/mm/mmap.c | 6 ++++--
arch/powerpc/mm/slice.c | 3 ++-
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index b2111baa0da6..355b6fe8a1e6 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -97,7 +97,8 @@ radix__arch_get_unmapped_area(struct file *filp, unsigned long addr,
struct vm_area_struct *vma;
struct vm_unmapped_area_info info;
- if (unlikely(addr > mm->context.addr_limit && addr < TASK_SIZE))
+ if (unlikely(addr > mm->context.addr_limit &&
+ mm->context.addr_limit != TASK_SIZE))
mm->context.addr_limit = TASK_SIZE;
if (len > mm->context.addr_limit - mmap_min_addr)
@@ -139,7 +140,8 @@ radix__arch_get_unmapped_area_topdown(struct file *filp,
unsigned long addr = addr0;
struct vm_unmapped_area_info info;
- if (unlikely(addr > mm->context.addr_limit && addr < TASK_SIZE))
+ if (unlikely(addr > mm->context.addr_limit &&
+ mm->context.addr_limit != TASK_SIZE))
mm->context.addr_limit = TASK_SIZE;
/* requested length too big for entire address space */
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 251b6bae7023..2d2d9760d057 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -419,7 +419,8 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
/*
* Check if we need to expland slice area.
*/
- if (unlikely(addr > mm->context.addr_limit && addr < TASK_SIZE)) {
+ if (unlikely(addr > mm->context.addr_limit &&
+ mm->context.addr_limit != TASK_SIZE)) {
mm->context.addr_limit = TASK_SIZE;
on_each_cpu(slice_flush_segments, mm, 1);
}
--
2.7.4
reply other threads:[~2017-04-11 14:16 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly 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=1491920135-13612-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com \
--to=aneesh.kumar@linux.vnet.ibm.com \
--cc=benh@kernel.crashing.org \
--cc=khandual@linux.vnet.ibm.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=paulus@samba.org \
--cc=ricklind@linux.vnet.ibm.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).