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 5.10-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_page.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From db42523b4f3e83ff86b53cdda219a9767c8b047f Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Thu, 1 Apr 2021 16:14:17 -0400
Subject: ftrace: Store the order of pages allocated in ftrace_page
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
commit db42523b4f3e83ff86b53cdda219a9767c8b047f upstream.
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>
Signed-off-by: Zheng Yejian <zhengyejian1@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/ftrace.c | 35 +++++++++++++++++------------------
1 file changed, 17 insertions(+), 18 deletions(-)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1091,7 +1091,7 @@ struct ftrace_page {
struct ftrace_page *next;
struct dyn_ftrace *records;
int index;
- int size;
+ int order;
};
#define ENTRY_SIZE sizeof(struct dyn_ftrace)
@@ -3188,7 +3188,7 @@ static int ftrace_allocate_records(struc
ftrace_number_of_groups++;
cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
- pg->size = cnt;
+ pg->order = order;
if (cnt > count)
cnt = count;
@@ -3201,7 +3201,6 @@ ftrace_allocate_pages(unsigned long num_
{
struct ftrace_page *start_pg;
struct ftrace_page *pg;
- int order;
int cnt;
if (!num_to_init)
@@ -3237,13 +3236,13 @@ ftrace_allocate_pages(unsigned long num_
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");
@@ -6239,6 +6238,7 @@ static int ftrace_process_locs(struct mo
p = start;
pg = start_pg;
while (p < end) {
+ unsigned long end_offset;
addr = ftrace_call_adjust(*p++);
/*
* Some architecture linkers will pad between
@@ -6249,7 +6249,8 @@ static int ftrace_process_locs(struct mo
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;
@@ -6418,7 +6419,6 @@ void ftrace_release_mod(struct module *m
struct ftrace_page **last_pg;
struct ftrace_page *tmp_page = NULL;
struct ftrace_page *pg;
- int order;
mutex_lock(&ftrace_lock);
@@ -6469,12 +6469,12 @@ void ftrace_release_mod(struct module *m
/* 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--;
}
}
@@ -6792,7 +6792,6 @@ void ftrace_free_mem(struct module *mod,
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);
@@ -6830,10 +6829,10 @@ void ftrace_free_mem(struct module *mod,
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);
Patches currently in stable-queue which might be from torvalds@xxxxxxxxxxxxxxxxxxxx are
queue-5.10/drm-atomic-fix-potential-use-after-free-in-nonblocking-commits.patch
queue-5.10/mm-rename-pud_page_vaddr-to-pud_pgtable-and-make-it-.patch
queue-5.10/workqueue-clean-up-work_-constant-types-clarify-masking.patch
queue-5.10/ftrace-store-the-order-of-pages-allocated-in-ftrace_page.patch
queue-5.10/wireguard-queueing-use-saner-cpu-selection-wrapping.patch
queue-5.10/mm-rename-p4d_page_vaddr-to-p4d_pgtable-and-make-it-.patch
