Subject: [merged] mm-prevent-setting-of-a-value-less-than-0-to-min_free_kbytes.patch removed from -mm tree
To: hanpt@xxxxxxxxxxxxxxxxxx,mhocko@xxxxxxx,rientjes@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 24 Jan 2014 10:59:07 -0800
The patch titled
Subject: mm: prevent setting of a value less than 0 to min_free_kbytes
has been removed from the -mm tree. Its filename was
mm-prevent-setting-of-a-value-less-than-0-to-min_free_kbytes.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Han Pingtian <hanpt@xxxxxxxxxxxxxxxxxx>
Subject: mm: prevent setting of a value less than 0 to min_free_kbytes
If echo -1 > /proc/vm/sys/min_free_kbytes, the system will hang. Changing
proc_dointvec() to proc_dointvec_minmax() in the
min_free_kbytes_sysctl_handler() can prevent this to happen.
mhocko said:
: You can still do echo $BIG_VALUE > /proc/vm/sys/min_free_kbytes and make
: your machine unusable but I agree that proc_dointvec_minmax is more
: suitable here as we already have:
:
: .proc_handler = min_free_kbytes_sysctl_handler,
: .extra1 = &zero,
:
: It used to work properly but then 6fce56ec91b5 ("sysctl: Remove references
: to ctl_name and strategy from the generic sysctl table") has removed
: sysctl_intvec strategy and so extra1 is ignored.
Signed-off-by: Han Pingtian <hanpt@xxxxxxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff -puN mm/page_alloc.c~mm-prevent-setting-of-a-value-less-than-0-to-min_free_kbytes mm/page_alloc.c
--- a/mm/page_alloc.c~mm-prevent-setting-of-a-value-less-than-0-to-min_free_kbytes
+++ a/mm/page_alloc.c
@@ -5754,7 +5754,12 @@ module_init(init_per_zone_wmark_min)
int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
- proc_dointvec(table, write, buffer, length, ppos);
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
if (write) {
user_min_free_kbytes = min_free_kbytes;
setup_per_zone_wmarks();
_
Patches currently in -mm which might be from hanpt@xxxxxxxxxxxxxxxxxx are
origin.patch
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