From 060e468737e44e83d2c9de1a664aaf998c12e532 Mon Sep 17 00:00:00 2001 From: Viktor Rosendahl Date: Thu, 11 Sep 2008 19:20:40 +0300 Subject: [PATCH] lowmem: add compatibility code This is a patch that will reintroduce the old sysctl lowmem variables as read only values in /proc/sys/vm. Some parts of the userland (at least libosso) are reading these and it would probably greatly ease the transition to the new scheme with memory limits in pages. We can revert this ugly patch when userland has moved to the new scheme. Signed-off-by: Viktor Rosendahl Signed-off-by: Tony Lindgren --- security/lowmem.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) diff --git a/security/lowmem.c b/security/lowmem.c index 87f6cecc1fb1..56f1f6e5900e 100644 --- a/security/lowmem.c +++ b/security/lowmem.c @@ -23,6 +23,10 @@ enum { VM_LOWMEM_ALLOWED_UIDS, VM_LOWMEM_ALLOWED_PAGES, VM_LOWMEM_FREE_PAGES, + VM_LOWMEM_DENY, + VM_LOWMEM_LEVEL1_NOTIFY, + VM_LOWMEM_LEVEL2_NOTIFY, + VM_LOWMEM_USED_PAGES }; static long deny_pages; @@ -33,6 +37,22 @@ static unsigned long lowmem_free_pages; static unsigned int allowed_uids[LOWMEM_MAX_UIDS]; static unsigned int minuid = 1; static unsigned int maxuid = 65535; +static unsigned int deny_percentage; +static unsigned int l1_notify, l2_notify; +static long used_pages; + +static int +proc_dointvec_used(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos); +static int +proc_dointvec_l1_notify(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos); +static int +proc_dointvec_l2_notify(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos); +static int +proc_dointvec_deny(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos); static ctl_table lowmem_table[] = { { @@ -44,6 +64,42 @@ static ctl_table lowmem_table[] = { .child = NULL, .proc_handler = &proc_dointvec, .strategy = &sysctl_intvec, + }, { + .ctl_name = VM_LOWMEM_DENY, + .procname = "lowmem_deny_watermark", + .data = &deny_percentage, + .maxlen = sizeof(unsigned int), + .mode = 0444, + .child = NULL, + .proc_handler = &proc_dointvec_deny, + .strategy = &sysctl_intvec, + }, { + .ctl_name = VM_LOWMEM_LEVEL1_NOTIFY, + .procname = "lowmem_notify_low", + .data = &l1_notify, + .maxlen = sizeof(unsigned int), + .mode = 0444, + .child = NULL, + .proc_handler = &proc_dointvec_l1_notify, + .strategy = &sysctl_intvec, + }, { + .ctl_name = VM_LOWMEM_LEVEL2_NOTIFY, + .procname = "lowmem_notify_high", + .data = &l2_notify, + .maxlen = sizeof(unsigned int), + .mode = 0444, + .child = NULL, + .proc_handler = &proc_dointvec_l2_notify, + .strategy = &sysctl_intvec, + }, { + .ctl_name = VM_LOWMEM_USED_PAGES, + .procname = "lowmem_used_pages", + .data = &used_pages, + .maxlen = sizeof(long), + .mode = 0444, + .child = NULL, + .proc_handler = &proc_dointvec_used, + .strategy = &sysctl_intvec, }, { .ctl_name = VM_LOWMEM_NOTIFY_LOW_PAGES, .procname = "lowmem_notify_low_pages", @@ -121,6 +177,44 @@ static struct kobj_attribute _name##_attr = __ATTR_RO(_name) static int low_watermark_reached, high_watermark_reached; +static int +proc_dointvec_l1_notify(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + l1_notify = + 100 - (100 * notify_low_pages + allowed_pages / 2) / allowed_pages; + return proc_dointvec(table, write, filp, buffer, lenp, ppos); +} + +static int +proc_dointvec_l2_notify(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + l2_notify = + 100 - (100 * notify_high_pages + allowed_pages / 2) / allowed_pages; + return proc_dointvec(table, write, filp, buffer, lenp, ppos); +} + +static int +proc_dointvec_deny(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + deny_percentage = + 100 - (100 * deny_pages + allowed_pages / 2) / allowed_pages; + return proc_dointvec(table, write, filp, buffer, lenp, ppos); +} + +static int +proc_dointvec_used(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + if (lowmem_free_pages > 0 && allowed_pages > lowmem_free_pages) + used_pages = allowed_pages - lowmem_free_pages; + else + used_pages = 0; + return proc_dointvec(table, write, filp, buffer, lenp, ppos); +} + static ssize_t low_watermark_show(struct kobject *kobj, struct kobj_attribute *attr, char *page) { -- 2.39.2