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ftrace: Store the order of pages allocated in ftrace_page 

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@mail.gmail.com/

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ change log written by Steven Rostedt ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Linus Torvalds 2021-04-01 16:14:17 -04:00 committed by Steven Rostedt (VMware)
parent f3ef7202ef
commit db42523b4f
1 changed files with 17 additions and 18 deletions
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35
kernel/trace/ftrace.c
View File

@ -1090,7 +1090,7 @@ struct ftrace_page {
struct ftrace_page *next;
struct dyn_ftrace *records;
int index;
int size;
int order;
};
#define ENTRY_SIZE sizeof(struct dyn_ftrace)
@ -3181,7 +3181,7 @@ 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;
@ -3194,7 +3194,6 @@ 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)
@ -3230,13 +3229,13 @@ 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");
@ -6188,6 +6187,7 @@ 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
@ -6198,7 +6198,8 @@ 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;
@ -6367,7 +6368,6 @@ 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);
@ -6418,12 +6418,12 @@ 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--;
}
}
@ -6741,7 +6741,6 @@ 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);
@ -6779,10 +6778,10 @@ 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);