[Devel] [PATCH RHEL COMMIT] ve/printk: Introduce struct "log_state" and virtualize log_buf/log_buf_len
Konstantin Khorenko
khorenko at virtuozzo.com
Fri Oct 1 18:22:07 MSK 2021
The commit is pushed to "branch-rh9-5.14.vz9.1.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after ark-5.14
------>
commit 2a9c7bf672a7769150cb0618868ebee20116ac72
Author: Vladimir Davydov <vdavydov.dev at gmail.com>
Date: Wed Sep 29 19:45:53 2021 +0300
ve/printk: Introduce struct "log_state" and virtualize log_buf/log_buf_len
https://jira.sw.ru/browse/PSBM-17899
Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
Signed-off-by: Stanislav Kinsburskiy <skinsbursky at virtuozzo.com>
+++
ve/printk: Fix printk virtualization
ve_printk() corrupts host's dmesg:
# dmesg|wc -l
599
# vzctl create 101
# vzctl set 101 --netif_add eth0 --save
# vzctl start 101
# vzctl exec 101 'tcpdump -w tcpdump.out -U -n -i eth0 esp'
# dmesg|wc -l
2
Add missing parts of prinkt virtualization to fix this.
https://jira.sw.ru/browse/PSBM-17899
https://jira.sw.ru/browse/PSBM-105442
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
Rebasing to vz9: part of vz8 commit:
d63aeb311a64 ("ve/printk: printk virtualization")
https://jira.sw.ru/browse/PSBM-133985
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
include/linux/printk.h | 13 ++++
include/linux/ve.h | 3 +
kernel/printk/printk.c | 165 +++++++++++++++++++++++++++++++++++++++++--------
kernel/ve/ve.c | 8 +++
4 files changed, 164 insertions(+), 25 deletions(-)
diff --git a/include/linux/printk.h b/include/linux/printk.h
index e834d78f0478..f178e2e5d7f5 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -176,6 +176,10 @@ int vprintk(const char *fmt, va_list args);
asmlinkage __printf(1, 2) __cold
int printk(const char *fmt, ...);
+struct ve_struct;
+int ve_log_init(struct ve_struct *ve);
+void ve_log_destroy(struct ve_struct *ve);
+
/*
* Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
*/
@@ -222,6 +226,15 @@ int printk(const char *s, ...)
{
return 0;
}
+static inline
+int ve_log_init(struct ve_struct *ve)
+{
+ return 0;
+}
+static inline
+void ve_log_destroy(struct ve_struct *ve)
+{
+}
static inline __printf(1, 2) __cold
int printk_deferred(const char *s, ...)
{
diff --git a/include/linux/ve.h b/include/linux/ve.h
index 248cdeb0a2e4..552fa577e2f9 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -50,6 +50,9 @@ struct ve_struct {
/* see vzcalluser.h for VE_FEATURE_XXX definitions */
__u64 features;
+ void *log_state;
+#define VE_LOG_BUF_LEN 4096
+
struct kstat_lat_pcpu_struct sched_lat_ve;
struct kmapset_key sysfs_perms_key;
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 142a58d124d9..77e6787c752e 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -44,6 +44,7 @@
#include <linux/irq_work.h>
#include <linux/ctype.h>
#include <linux/uio.h>
+#include <linux/ve.h>
#include <linux/sched/clock.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
@@ -408,8 +409,6 @@ static struct latched_seq clear_seq = {
#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
#define LOG_BUF_LEN_MAX (u32)(1 << 31)
static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
-static char *log_buf = __log_buf;
-static u32 log_buf_len = __LOG_BUF_LEN;
/*
* Define the average message size. This only affects the number of
@@ -427,6 +426,34 @@ _DEFINE_PRINTKRB(printk_rb_static, CONFIG_LOG_BUF_SHIFT - PRB_AVGBITS,
static struct printk_ringbuffer printk_rb_dynamic;
static struct printk_ringbuffer *prb = &printk_rb_static;
+static struct log_state {
+ char *buf;
+ u32 buf_len;
+} init_log_state = {
+ .buf = __log_buf,
+ .buf_len = __LOG_BUF_LEN,
+};
+
+/* kdump relies on some log_* symbols, let's make it happy */
+#define DEFINE_STRUCT_MEMBER_ALIAS(name, inst, memb) \
+static void ____ ## name ## _definition(void) __attribute__((used)); \
+static void ____ ## name ## _definition(void) \
+{ \
+ asm (".globl " #name "\n\t.set " #name ", " #inst "+%c0" \
+ : : "g" (offsetof(typeof(inst), memb))); \
+} \
+extern typeof(inst.memb) name;
+#undef DEFINE_STRUCT_MEMBER_ALIAS
+
+static inline struct log_state *ve_log_state(void)
+{
+ struct log_state *log = &init_log_state;
+#ifdef CONFIG_VE
+ if (get_exec_env()->log_state)
+ log = get_exec_env()->log_state;
+#endif
+ return log;
+}
/*
* We cannot access per-CPU data (e.g. per-CPU flush irq_work) before
@@ -468,13 +495,13 @@ static u64 latched_seq_read_nolock(struct latched_seq *ls)
/* Return log buffer address */
char *log_buf_addr_get(void)
{
- return log_buf;
+ return init_log_state.buf;
}
/* Return log buffer size */
u32 log_buf_len_get(void)
{
- return log_buf_len;
+ return init_log_state.buf_len;
}
/*
@@ -485,13 +512,14 @@ u32 log_buf_len_get(void)
#define MAX_LOG_TAKE_PART 4
static const char trunc_msg[] = "<truncated>";
-static void truncate_msg(u16 *text_len, u16 *trunc_msg_len)
+static void truncate_msg(struct log_state *log,
+ u16 *text_len, u16 *trunc_msg_len)
{
/*
* The message should not take the whole buffer. Otherwise, it might
* get removed too soon.
*/
- u32 max_text_len = log_buf_len / MAX_LOG_TAKE_PART;
+ u32 max_text_len = log->buf_len / MAX_LOG_TAKE_PART;
if (*text_len > max_text_len)
*text_len = max_text_len;
@@ -642,14 +670,20 @@ struct devkmsg_user {
struct printk_record record;
};
-static __printf(3, 4) __cold
-int devkmsg_emit(int facility, int level, const char *fmt, ...)
+asmlinkage int vprintk_emit_log(struct log_state *log,
+ int facility, int level,
+ const struct dev_printk_info *dev_info,
+ const char *fmt, va_list args);
+
+static __printf(4, 5) __cold
+int devkmsg_emit_log(struct log_state *log, int facility, int level,
+ const char *fmt, ...)
{
va_list args;
int r;
va_start(args, fmt);
- r = vprintk_emit(facility, level, NULL, fmt, args);
+ r = vprintk_emit_log(log, facility, level, NULL, fmt, args);
va_end(args);
return r;
@@ -657,6 +691,7 @@ int devkmsg_emit(int facility, int level, const char *fmt, ...)
static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from)
{
+ struct log_state *log = ve_log_state();
char *buf, *line;
int level = default_message_loglevel;
int facility = 1; /* LOG_USER */
@@ -712,7 +747,7 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from)
}
}
- devkmsg_emit(facility, level, "%s", line);
+ devkmsg_emit_log(log, facility, level, "%s", line);
kfree(buf);
return ret;
}
@@ -987,11 +1022,11 @@ static void __init log_buf_len_update(u64 size)
if (size)
size = roundup_pow_of_two(size);
- if (size > log_buf_len)
+ if (size > init_log_state.buf_len)
new_log_buf_len = (unsigned long)size;
}
-/* save requested log_buf_len since it's too early to process it */
+/* save requested log->buf_len since it's too early to process it */
static int __init log_buf_len_setup(char *str)
{
u64 size;
@@ -1077,6 +1112,7 @@ static char setup_text_buf[LOG_LINE_MAX] __initdata;
void __init setup_log_buf(int early)
{
+ struct log_state *log = &init_log_state;
struct printk_info *new_infos;
unsigned int new_descs_count;
struct prb_desc *new_descs;
@@ -1097,7 +1133,7 @@ void __init setup_log_buf(int early)
if (!early)
set_percpu_data_ready();
- if (log_buf != __log_buf)
+ if (log->buf != __log_buf)
return;
if (!early && !new_log_buf_len)
@@ -1144,8 +1180,8 @@ void __init setup_log_buf(int early)
printk_safe_enter_irqsave(flags);
- log_buf_len = new_log_buf_len;
- log_buf = new_log_buf;
+ log->buf_len = new_log_buf_len;
+ log->buf = new_log_buf;
new_log_buf_len = 0;
free = __LOG_BUF_LEN;
@@ -1166,7 +1202,7 @@ void __init setup_log_buf(int early)
prb_next_seq(&printk_rb_static) - seq);
}
- pr_info("log_buf_len: %u bytes\n", log_buf_len);
+ pr_info("log_buf_len: %u bytes\n", log->buf_len);
pr_info("early log buf free: %u(%u%%)\n",
free, (free * 100) / __LOG_BUF_LEN);
return;
@@ -1632,6 +1668,7 @@ static u64 read_syslog_seq_irq(void)
int do_syslog(int type, char __user *buf, int len, int source)
{
+ struct log_state *log = ve_log_state();
struct printk_info info;
bool clear = false;
static int saved_console_loglevel = LOGLEVEL_DEFAULT;
@@ -1741,7 +1778,7 @@ int do_syslog(int type, char __user *buf, int len, int source)
break;
/* Size of the log buffer */
case SYSLOG_ACTION_SIZE_BUFFER:
- error = log_buf_len;
+ error = log->buf_len;
break;
default:
error = -EINVAL;
@@ -2031,8 +2068,8 @@ static u16 printk_sprint(char *text, u16 size, int facility, enum log_flags *lfl
return text_len;
}
-__printf(4, 0)
-int vprintk_store(int facility, int level,
+__printf(5, 0)
+int vprintk_store_log(struct log_state *log, int facility, int level,
const struct dev_printk_info *dev_info,
const char *fmt, va_list args)
{
@@ -2104,7 +2141,7 @@ int vprintk_store(int facility, int level,
prb_rec_init_wr(&r, reserve_size);
if (!prb_reserve(&e, prb, &r)) {
/* truncate the message if it is too long for empty buffer */
- truncate_msg(&reserve_size, &trunc_msg_len);
+ truncate_msg(log, &reserve_size, &trunc_msg_len);
prb_rec_init_wr(&r, reserve_size + trunc_msg_len);
if (!prb_reserve(&e, prb, &r))
@@ -2133,9 +2170,18 @@ int vprintk_store(int facility, int level,
return (text_len + trunc_msg_len);
}
-asmlinkage int vprintk_emit(int facility, int level,
- const struct dev_printk_info *dev_info,
- const char *fmt, va_list args)
+int vprintk_store(int facility, int level,
+ const struct dev_printk_info *dev_info,
+ const char *fmt, va_list args)
+{
+ return vprintk_store_log(&init_log_state, facility, level,
+ dev_info, fmt, args);
+}
+
+asmlinkage int vprintk_emit_log(struct log_state *log,
+ int facility, int level,
+ const struct dev_printk_info *dev_info,
+ const char *fmt, va_list args)
{
int printed_len;
bool in_sched = false;
@@ -2154,7 +2200,7 @@ asmlinkage int vprintk_emit(int facility, int level,
printk_delay();
printk_safe_enter_irqsave(flags);
- printed_len = vprintk_store(facility, level, dev_info, fmt, args);
+ printed_len = vprintk_store_log(log, facility, level, dev_info, fmt, args);
printk_safe_exit_irqrestore(flags);
/* If called from the scheduler, we can not call up(). */
@@ -2178,8 +2224,23 @@ asmlinkage int vprintk_emit(int facility, int level,
wake_up_klogd();
return printed_len;
}
+
+asmlinkage int vprintk_emit(int facility, int level,
+ const struct dev_printk_info *dev_info,
+ const char *fmt, va_list args)
+{
+ return vprintk_emit_log(&init_log_state,
+ facility, level, dev_info,
+ fmt, args);
+}
EXPORT_SYMBOL(vprintk_emit);
+static int __vprintk(const char *fmt, va_list args)
+{
+ return vprintk_emit_log(ve_log_state(), 0, LOGLEVEL_DEFAULT,
+ NULL, fmt, args);
+}
+
int vprintk_default(const char *fmt, va_list args)
{
return vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, fmt, args);
@@ -3530,7 +3591,61 @@ void kmsg_dump_rewind(struct kmsg_dump_iter *iter)
}
EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
-#endif
+#ifdef CONFIG_VE
+int setup_log_buf_ve(struct log_state *log, struct ve_struct *ve, int early)
+{
+ unsigned long local_log_buf_len;
+ int ret = -EINVAL;
+
+ char *new_log_buf;
+
+ local_log_buf_len = VE_LOG_BUF_LEN;
+
+ ret = -ENOMEM;
+ new_log_buf = kmalloc(local_log_buf_len, GFP_KERNEL);
+ if (unlikely(!new_log_buf)) {
+ pr_err("log_buf_len: %lu text bytes not available\n",
+ local_log_buf_len);
+ goto out;
+ }
+
+ log->buf_len = local_log_buf_len;
+ log->buf = new_log_buf;
+
+ return 0;
+out:
+ return ret;
+}
+
+int ve_log_init(struct ve_struct *ve)
+{
+ struct log_state *log;
+ int ret;
+
+ log = kzalloc(sizeof(*log), GFP_KERNEL);
+ if (!log)
+ return -ENOMEM;
+
+ ret = setup_log_buf_ve(log, ve, 0);
+ if (!ret) {
+ kfree(log);
+ return ret;
+ }
+
+ ve->log_state = log;
+ return 0;
+}
+
+void ve_log_destroy(struct ve_struct *ve)
+{
+ struct log_state *log = ve->log_state;
+
+ kfree(log->buf);
+ kfree(log);
+}
+#endif /* CONFIG_VE */
+
+#endif /* CONFIG_PRINTK */
#ifdef CONFIG_SMP
static atomic_t printk_cpulock_owner = ATOMIC_INIT(-1);
diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
index 8f192ee41832..e3a07d4c9fe4 100644
--- a/kernel/ve/ve.c
+++ b/kernel/ve/ve.c
@@ -590,12 +590,19 @@ static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_
atomic_set(&ve->netns_avail_nr, NETNS_MAX_NR_DEFAULT);
ve->netns_max_nr = NETNS_MAX_NR_DEFAULT;
+
+ err = ve_log_init(ve);
+ if (err)
+ goto err_log;
+
do_init:
init_rwsem(&ve->op_sem);
INIT_LIST_HEAD(&ve->ve_list);
kmapset_init_key(&ve->sysfs_perms_key);
return &ve->css;
+err_log:
+ free_percpu(ve->sched_lat_ve.cur);
err_lat:
kmem_cache_free(ve_cachep, ve);
err_ve:
@@ -637,6 +644,7 @@ static void ve_destroy(struct cgroup_subsys_state *css)
struct ve_struct *ve = css_to_ve(css);
kmapset_unlink(&ve->sysfs_perms_key, &sysfs_ve_perms_set);
+ ve_log_destroy(ve);
free_percpu(ve->sched_lat_ve.cur);
kmem_cache_free(ve_cachep, ve);
}
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