crash/0049-Fix-for-mm_struct.rss_stat-conversion-into-percpu_co.patch

From c05bbb36fcb468bce384ee4b8e30a0f5748bc4ae Mon Sep 17 00:00:00 2001
From: Kazuhito Hagio <k-hagio-ab@nec.com>
Date: Thu, 15 Dec 2022 11:31:38 +0900
Subject: [PATCH 49/89] Fix for mm_struct.rss_stat conversion into
 percpu_counter

Kernel commit f1a7941243c1 ("mm: convert mm's rss stats into
percpu_counter"), which is contained in Linux 6.2-rc1 and later
kernels, changed mm_struct.rss_stat from struct mm_rss_stat into an
array of struct percpu_counter.

Without the patch, "ps" and several commands fail with the following
error message:

  ps: invalid structure member offset: mm_rss_stat_count
      FILE: memory.c  LINE: 4724  FUNCTION: get_task_mem_usage()

Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
---
 defs.h    |  3 +++
 kernel.c  |  2 ++
 memory.c  | 14 +++++++++++++-
 symbols.c |  6 ++++--
 tools.c   | 28 ++++++++++++++++++++++++++++
 5 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/defs.h b/defs.h
index b7d76330141a..e4732c885371 100644
--- a/defs.h
+++ b/defs.h
@@ -2181,6 +2181,7 @@ struct offset_table {                    /* stash of commonly-used offsets */
 	long blk_mq_tags_nr_reserved_tags;
 	long blk_mq_tags_rqs;
 	long request_queue_hctx_table;
+	long percpu_counter_counters;
 };
 
 struct size_table {         /* stash of commonly-used sizes */
@@ -2351,6 +2352,7 @@ struct size_table {         /* stash of commonly-used sizes */
 	long sbitmap_queue;
 	long sbq_wait_state;
 	long blk_mq_tags;
+	long percpu_counter;
 };
 
 struct array_table {
@@ -5307,6 +5309,7 @@ struct rb_node *rb_right(struct rb_node *, struct rb_node *);
 struct rb_node *rb_left(struct rb_node *, struct rb_node *);
 struct rb_node *rb_next(struct rb_node *);
 struct rb_node *rb_last(struct rb_root *);
+long percpu_counter_sum_positive(ulong fbc);
 
 /* 
  *  symbols.c 
diff --git a/kernel.c b/kernel.c
index 2a1c1c391414..3ca513962970 100644
--- a/kernel.c
+++ b/kernel.c
@@ -316,6 +316,8 @@ kernel_init()
 	}
 
 	MEMBER_OFFSET_INIT(percpu_counter_count, "percpu_counter", "count");
+	MEMBER_OFFSET_INIT(percpu_counter_counters, "percpu_counter", "counters");
+	STRUCT_SIZE_INIT(percpu_counter, "percpu_counter");
 
 	if (STRUCT_EXISTS("runqueue")) {
 		rqstruct = "runqueue";
diff --git a/memory.c b/memory.c
index 9c15c1b745ef..9d003713534b 100644
--- a/memory.c
+++ b/memory.c
@@ -4713,7 +4713,7 @@ get_task_mem_usage(ulong task, struct task_mem_usage *tm)
 		/*
 		 *  Latest kernels have mm_struct.mm_rss_stat[].
 		 */ 
-		if (VALID_MEMBER(mm_struct_rss_stat)) {
+		if (VALID_MEMBER(mm_struct_rss_stat) && VALID_MEMBER(mm_rss_stat_count)) {
 			long anonpages, filepages, count;
 
 			anonpages = tt->anonpages;
@@ -4737,6 +4737,18 @@ get_task_mem_usage(ulong task, struct task_mem_usage *tm)
 				(anonpages * sizeof(long)));
 			if (count > 0)
 				rss += count;
+
+		} else if (VALID_MEMBER(mm_struct_rss_stat)) {
+			/* 6.2: struct percpu_counter rss_stat[NR_MM_COUNTERS] */
+			ulong fbc;
+
+			fbc = tc->mm_struct + OFFSET(mm_struct_rss_stat) +
+				(tt->filepages * SIZE(percpu_counter));
+			rss += percpu_counter_sum_positive(fbc);
+
+			fbc = tc->mm_struct + OFFSET(mm_struct_rss_stat) +
+				(tt->anonpages * SIZE(percpu_counter));
+			rss += percpu_counter_sum_positive(fbc);
 		}
 
 		/* Check whether SPLIT_RSS_COUNTING is enabled */
diff --git a/symbols.c b/symbols.c
index a94660538492..657f50706819 100644
--- a/symbols.c
+++ b/symbols.c
@@ -10645,8 +10645,8 @@ dump_offset_table(char *spec, ulong makestruct)
 		OFFSET(ktime_t_nsec));
 	fprintf(fp, "              atomic_t_counter: %ld\n",
 		OFFSET(atomic_t_counter));
-	fprintf(fp, "          percpu_counter_count: %ld\n",
-		OFFSET(percpu_counter_count));
+	fprintf(fp, "          percpu_counter_count: %ld\n", OFFSET(percpu_counter_count));
+	fprintf(fp, "       percpu_counter_counters: %ld\n", OFFSET(percpu_counter_counters));
 	fprintf(fp, "             sk_buff_head_next: %ld\n",
 		OFFSET(sk_buff_head_next));
 	fprintf(fp, "             sk_buff_head_qlen: %ld\n",
@@ -11040,6 +11040,8 @@ dump_offset_table(char *spec, ulong makestruct)
 	fprintf(fp, "                sbq_wait_state: %ld\n", SIZE(sbq_wait_state));
 	fprintf(fp, "                   blk_mq_tags: %ld\n", SIZE(blk_mq_tags));
 
+	fprintf(fp, "                percpu_counter: %ld\n", SIZE(percpu_counter));
+
         fprintf(fp, "\n                   array_table:\n");
 	/*
 	 *  Use get_array_length() for those fields not set up at init-time;
diff --git a/tools.c b/tools.c
index 6fa3c70bac2b..7f64bd6328cf 100644
--- a/tools.c
+++ b/tools.c
@@ -6902,3 +6902,31 @@ rb_last(struct rb_root *root)
 
 	return node;
 }
+
+long
+percpu_counter_sum_positive(ulong fbc)
+{
+	int i, count;
+	ulong addr;
+	long ret;
+
+	if (INVALID_MEMBER(percpu_counter_count))
+		return 0;
+
+	readmem(fbc + OFFSET(percpu_counter_count), KVADDR, &ret,
+		sizeof(long long), "percpu_counter.count", FAULT_ON_ERROR);
+
+	if (INVALID_MEMBER(percpu_counter_counters)) /* !CONFIG_SMP */
+		return (ret < 0) ? 0 : ret;
+
+	readmem(fbc + OFFSET(percpu_counter_counters), KVADDR, &addr,
+		sizeof(void *), "percpu_counter.counters", FAULT_ON_ERROR);
+
+	for (i = 0; i < kt->cpus; i++) {
+		readmem(addr + kt->__per_cpu_offset[i], KVADDR, &count,
+			sizeof(int), "percpu_counter.counters count", FAULT_ON_ERROR);
+		ret += count;
+	}
+
+	return (ret < 0) ? 0 : ret;
+}
-- 
2.37.1