This is a note to let you know that I've just added the patch titled
ftrace: Store the order of pages allocated in ftrace_page
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ftrace-store-the-order-of-pages-allocated-in-ftrace_.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5d879a6d79b96223a9a3018a507c46d747d8c77c
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Thu Apr 1 16:14:17 2021 -0400
ftrace: Store the order of pages allocated in ftrace_page
[ Upstream commit db42523b4f3e83ff86b53cdda219a9767c8b047f ]
Instead of saving the size of the records field of the ftrace_page, store
the order it uses to allocate the pages, as that is what is needed to know
in order to free the pages. This simplifies the code.
Link: https://lore.kernel.org/lkml/CAHk-=whyMxheOqXAORt9a7JK9gc9eHTgCJ55Pgs4p=X3RrQubQ@xxxxxxxxxxxxxx/
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[ change log written by Steven Rostedt ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Stable-dep-of: 26efd79c4624 ("ftrace: Fix possible warning on checking all pages used in ftrace_process_locs()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 5f5a766bf73bb..aa2530cbcb8fd 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1100,7 +1100,7 @@ struct ftrace_page {
struct ftrace_page *next;
struct dyn_ftrace *records;
int index;
- int size;
+ int order;
};
#define ENTRY_SIZE sizeof(struct dyn_ftrace)
@@ -3029,7 +3029,7 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count)
ftrace_number_of_groups++;
cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
- pg->size = cnt;
+ pg->order = order;
if (cnt > count)
cnt = count;
@@ -3042,7 +3042,6 @@ ftrace_allocate_pages(unsigned long num_to_init)
{
struct ftrace_page *start_pg;
struct ftrace_page *pg;
- int order;
int cnt;
if (!num_to_init)
@@ -3078,13 +3077,13 @@ ftrace_allocate_pages(unsigned long num_to_init)
free_pages:
pg = start_pg;
while (pg) {
- order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- if (order >= 0)
- free_pages((unsigned long)pg->records, order);
+ if (pg->records) {
+ free_pages((unsigned long)pg->records, pg->order);
+ ftrace_number_of_pages -= 1 << pg->order;
+ }
start_pg = pg->next;
kfree(pg);
pg = start_pg;
- ftrace_number_of_pages -= 1 << order;
ftrace_number_of_groups--;
}
pr_info("ftrace: FAILED to allocate memory for functions\n");
@@ -5676,6 +5675,7 @@ static int ftrace_process_locs(struct module *mod,
p = start;
pg = start_pg;
while (p < end) {
+ unsigned long end_offset;
addr = ftrace_call_adjust(*p++);
/*
* Some architecture linkers will pad between
@@ -5686,7 +5686,8 @@ static int ftrace_process_locs(struct module *mod,
if (!addr)
continue;
- if (pg->index == pg->size) {
+ end_offset = (pg->index+1) * sizeof(pg->records[0]);
+ if (end_offset > PAGE_SIZE << pg->order) {
/* We should have allocated enough */
if (WARN_ON(!pg->next))
break;
@@ -5826,7 +5827,6 @@ void ftrace_release_mod(struct module *mod)
struct ftrace_page **last_pg;
struct ftrace_page *tmp_page = NULL;
struct ftrace_page *pg;
- int order;
mutex_lock(&ftrace_lock);
@@ -5877,12 +5877,12 @@ void ftrace_release_mod(struct module *mod)
/* Needs to be called outside of ftrace_lock */
clear_mod_from_hashes(pg);
- order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- if (order >= 0)
- free_pages((unsigned long)pg->records, order);
+ if (pg->records) {
+ free_pages((unsigned long)pg->records, pg->order);
+ ftrace_number_of_pages -= 1 << pg->order;
+ }
tmp_page = pg->next;
kfree(pg);
- ftrace_number_of_pages -= 1 << order;
ftrace_number_of_groups--;
}
}
@@ -6185,7 +6185,6 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
struct ftrace_mod_map *mod_map = NULL;
struct ftrace_init_func *func, *func_next;
struct list_head clear_hash;
- int order;
INIT_LIST_HEAD(&clear_hash);
@@ -6223,10 +6222,10 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
ftrace_update_tot_cnt--;
if (!pg->index) {
*last_pg = pg->next;
- order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- if (order >= 0)
- free_pages((unsigned long)pg->records, order);
- ftrace_number_of_pages -= 1 << order;
+ if (pg->records) {
+ free_pages((unsigned long)pg->records, pg->order);
+ ftrace_number_of_pages -= 1 << pg->order;
+ }
ftrace_number_of_groups--;
kfree(pg);
pg = container_of(last_pg, struct ftrace_page, next);
