AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-16 00:36:40 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity
c67dda88cc
linux_dsm_epyc7002/kernel/trace/tracing_map.c
Kees Cook 42bc47b353 treewide: Use array_size() in vmalloc() 
The vmalloc() function has no 2-factor argument form, so multiplication
factors need to be wrapped in array_size(). This patch replaces cases of:

        vmalloc(a * b)

with:
        vmalloc(array_size(a, b))

as well as handling cases of:

        vmalloc(a * b * c)

with:

        vmalloc(array3_size(a, b, c))

This does, however, attempt to ignore constant size factors like:

        vmalloc(4 * 1024)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  vmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  vmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  vmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_ID
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_ID
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

  vmalloc(
-	SIZE * COUNT
+	array_size(COUNT, SIZE)
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  vmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  vmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  vmalloc(C1 * C2 * C3, ...)
|
  vmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression E1, E2;
constant C1, C2;
@@

(
  vmalloc(C1 * C2, ...)
|
  vmalloc(
-	E1 * E2
+	array_size(E1, E2)
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00

1135 lines
30 KiB
C
Raw Blame History

/*
* tracing_map - lock-free map for tracing
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
*
* tracing_map implementation inspired by lock-free map algorithms
* originated by Dr. Cliff Click:
*
* http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable
* http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf
*/
#include <linux/vmalloc.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include "tracing_map.h"
#include "trace.h"
/*
* NOTE: For a detailed description of the data structures used by
* these functions (such as tracing_map_elt) please see the overview
* of tracing_map data structures at the beginning of tracing_map.h.
*/
/**
* tracing_map_update_sum - Add a value to a tracing_map_elt's sum field
* @elt: The tracing_map_elt
* @i: The index of the given sum associated with the tracing_map_elt
* @n: The value to add to the sum
*
* Add n to sum i associated with the specified tracing_map_elt
* instance. The index i is the index returned by the call to
* tracing_map_add_sum_field() when the tracing map was set up.
*/
void tracing_map_update_sum(struct tracing_map_elt *elt, unsigned int i, u64 n)
{
atomic64_add(n, &elt->fields[i].sum);
}
/**
* tracing_map_read_sum - Return the value of a tracing_map_elt's sum field
* @elt: The tracing_map_elt
* @i: The index of the given sum associated with the tracing_map_elt
*
* Retrieve the value of the sum i associated with the specified
* tracing_map_elt instance. The index i is the index returned by the
* call to tracing_map_add_sum_field() when the tracing map was set
* up.
*
* Return: The sum associated with field i for elt.
*/
u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i)
{
return (u64)atomic64_read(&elt->fields[i].sum);
}
/**
* tracing_map_set_var - Assign a tracing_map_elt's variable field
* @elt: The tracing_map_elt
* @i: The index of the given variable associated with the tracing_map_elt
* @n: The value to assign
*
* Assign n to variable i associated with the specified tracing_map_elt
* instance. The index i is the index returned by the call to
* tracing_map_add_var() when the tracing map was set up.
*/
void tracing_map_set_var(struct tracing_map_elt *elt, unsigned int i, u64 n)
{
atomic64_set(&elt->vars[i], n);
elt->var_set[i] = true;
}
/**
* tracing_map_var_set - Return whether or not a variable has been set
* @elt: The tracing_map_elt
* @i: The index of the given variable associated with the tracing_map_elt
*
* Return true if the variable has been set, false otherwise. The
* index i is the index returned by the call to tracing_map_add_var()
* when the tracing map was set up.
*/
bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i)
{
return elt->var_set[i];
}
/**
* tracing_map_read_var - Return the value of a tracing_map_elt's variable field
* @elt: The tracing_map_elt
* @i: The index of the given variable associated with the tracing_map_elt
*
* Retrieve the value of the variable i associated with the specified
* tracing_map_elt instance. The index i is the index returned by the
* call to tracing_map_add_var() when the tracing map was set
* up.
*
* Return: The variable value associated with field i for elt.
*/
u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i)
{
return (u64)atomic64_read(&elt->vars[i]);
}
/**
* tracing_map_read_var_once - Return and reset a tracing_map_elt's variable field
* @elt: The tracing_map_elt
* @i: The index of the given variable associated with the tracing_map_elt
*
* Retrieve the value of the variable i associated with the specified
* tracing_map_elt instance, and reset the variable to the 'not set'
* state. The index i is the index returned by the call to
* tracing_map_add_var() when the tracing map was set up. The reset
* essentially makes the variable a read-once variable if it's only
* accessed using this function.
*
* Return: The variable value associated with field i for elt.
*/
u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i)
{
elt->var_set[i] = false;
return (u64)atomic64_read(&elt->vars[i]);
}
int tracing_map_cmp_string(void *val_a, void *val_b)
{
char *a = val_a;
char *b = val_b;
return strcmp(a, b);
}
int tracing_map_cmp_none(void *val_a, void *val_b)
{
return 0;
}
static int tracing_map_cmp_atomic64(void *val_a, void *val_b)
{
u64 a = atomic64_read((atomic64_t *)val_a);
u64 b = atomic64_read((atomic64_t *)val_b);
return (a > b) ? 1 : ((a < b) ? -1 : 0);
}
#define DEFINE_TRACING_MAP_CMP_FN(type) \
static int tracing_map_cmp_##type(void *val_a, void *val_b) \
{ \
type a = *(type *)val_a; \
type b = *(type *)val_b; \
\
return (a > b) ? 1 : ((a < b) ? -1 : 0); \
}
DEFINE_TRACING_MAP_CMP_FN(s64);
DEFINE_TRACING_MAP_CMP_FN(u64);
DEFINE_TRACING_MAP_CMP_FN(s32);
DEFINE_TRACING_MAP_CMP_FN(u32);
DEFINE_TRACING_MAP_CMP_FN(s16);
DEFINE_TRACING_MAP_CMP_FN(u16);
DEFINE_TRACING_MAP_CMP_FN(s8);
DEFINE_TRACING_MAP_CMP_FN(u8);
tracing_map_cmp_fn_t tracing_map_cmp_num(int field_size,
int field_is_signed)
{
tracing_map_cmp_fn_t fn = tracing_map_cmp_none;
switch (field_size) {
case 8:
if (field_is_signed)
fn = tracing_map_cmp_s64;
else
fn = tracing_map_cmp_u64;
break;
case 4:
if (field_is_signed)
fn = tracing_map_cmp_s32;
else
fn = tracing_map_cmp_u32;
break;
case 2:
if (field_is_signed)
fn = tracing_map_cmp_s16;
else
fn = tracing_map_cmp_u16;
break;
case 1:
if (field_is_signed)
fn = tracing_map_cmp_s8;
else
fn = tracing_map_cmp_u8;
break;
}
return fn;
}
static int tracing_map_add_field(struct tracing_map *map,
tracing_map_cmp_fn_t cmp_fn)
{
int ret = -EINVAL;
if (map->n_fields < TRACING_MAP_FIELDS_MAX) {
ret = map->n_fields;
map->fields[map->n_fields++].cmp_fn = cmp_fn;
}
return ret;
}
/**
* tracing_map_add_sum_field - Add a field describing a tracing_map sum
* @map: The tracing_map
*
* Add a sum field to the key and return the index identifying it in
* the map and associated tracing_map_elts. This is the index used
* for instance to update a sum for a particular tracing_map_elt using
* tracing_map_update_sum() or reading it via tracing_map_read_sum().
*
* Return: The index identifying the field in the map and associated
* tracing_map_elts, or -EINVAL on error.
*/
int tracing_map_add_sum_field(struct tracing_map *map)
{
return tracing_map_add_field(map, tracing_map_cmp_atomic64);
}
/**
* tracing_map_add_var - Add a field describing a tracing_map var
* @map: The tracing_map
*
* Add a var to the map and return the index identifying it in the map
* and associated tracing_map_elts. This is the index used for
* instance to update a var for a particular tracing_map_elt using
* tracing_map_update_var() or reading it via tracing_map_read_var().
*
* Return: The index identifying the var in the map and associated
* tracing_map_elts, or -EINVAL on error.
*/
int tracing_map_add_var(struct tracing_map *map)
{
int ret = -EINVAL;
if (map->n_vars < TRACING_MAP_VARS_MAX)
ret = map->n_vars++;
return ret;
}
/**
* tracing_map_add_key_field - Add a field describing a tracing_map key
* @map: The tracing_map
* @offset: The offset within the key
* @cmp_fn: The comparison function that will be used to sort on the key
*
* Let the map know there is a key and that if it's used as a sort key
* to use cmp_fn.
*
* A key can be a subset of a compound key; for that purpose, the
* offset param is used to describe where within the the compound key
* the key referenced by this key field resides.
*
* Return: The index identifying the field in the map and associated
* tracing_map_elts, or -EINVAL on error.
*/
int tracing_map_add_key_field(struct tracing_map *map,
unsigned int offset,
tracing_map_cmp_fn_t cmp_fn)
{
int idx = tracing_map_add_field(map, cmp_fn);
if (idx < 0)
return idx;
map->fields[idx].offset = offset;
map->key_idx[map->n_keys++] = idx;
return idx;
}
void tracing_map_array_clear(struct tracing_map_array *a)
{
unsigned int i;
if (!a->pages)
return;
for (i = 0; i < a->n_pages; i++)
memset(a->pages[i], 0, PAGE_SIZE);
}
void tracing_map_array_free(struct tracing_map_array *a)
{
unsigned int i;
if (!a)
return;
if (!a->pages)
goto free;
for (i = 0; i < a->n_pages; i++) {
if (!a->pages[i])
break;
free_page((unsigned long)a->pages[i]);
}
kfree(a->pages);
free:
kfree(a);
}
struct tracing_map_array *tracing_map_array_alloc(unsigned int n_elts,
unsigned int entry_size)
{
struct tracing_map_array *a;
unsigned int i;
a = kzalloc(sizeof(*a), GFP_KERNEL);
if (!a)
return NULL;
a->entry_size_shift = fls(roundup_pow_of_two(entry_size) - 1);
a->entries_per_page = PAGE_SIZE / (1 << a->entry_size_shift);
a->n_pages = n_elts / a->entries_per_page;
if (!a->n_pages)
a->n_pages = 1;
a->entry_shift = fls(a->entries_per_page) - 1;
a->entry_mask = (1 << a->entry_shift) - 1;
a->pages = kcalloc(a->n_pages, sizeof(void *), GFP_KERNEL);
if (!a->pages)
goto free;
for (i = 0; i < a->n_pages; i++) {
a->pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
if (!a->pages[i])
goto free;
}
out:
return a;
free:
tracing_map_array_free(a);
a = NULL;
goto out;
}
static void tracing_map_elt_clear(struct tracing_map_elt *elt)
{
unsigned i;
for (i = 0; i < elt->map->n_fields; i++)
if (elt->fields[i].cmp_fn == tracing_map_cmp_atomic64)
atomic64_set(&elt->fields[i].sum, 0);
for (i = 0; i < elt->map->n_vars; i++) {
atomic64_set(&elt->vars[i], 0);
elt->var_set[i] = false;
}
if (elt->map->ops && elt->map->ops->elt_clear)
elt->map->ops->elt_clear(elt);
}
static void tracing_map_elt_init_fields(struct tracing_map_elt *elt)
{
unsigned int i;
tracing_map_elt_clear(elt);
for (i = 0; i < elt->map->n_fields; i++) {
elt->fields[i].cmp_fn = elt->map->fields[i].cmp_fn;
if (elt->fields[i].cmp_fn != tracing_map_cmp_atomic64)
elt->fields[i].offset = elt->map->fields[i].offset;
}
}
static void tracing_map_elt_free(struct tracing_map_elt *elt)
{
if (!elt)
return;
if (elt->map->ops && elt->map->ops->elt_free)
elt->map->ops->elt_free(elt);
kfree(elt->fields);
kfree(elt->vars);
kfree(elt->var_set);
kfree(elt->key);
kfree(elt);
}
static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map)
{
struct tracing_map_elt *elt;
int err = 0;
elt = kzalloc(sizeof(*elt), GFP_KERNEL);
if (!elt)
return ERR_PTR(-ENOMEM);
elt->map = map;
elt->key = kzalloc(map->key_size, GFP_KERNEL);
if (!elt->key) {
err = -ENOMEM;
goto free;
}
elt->fields = kcalloc(map->n_fields, sizeof(*elt->fields), GFP_KERNEL);
if (!elt->fields) {
err = -ENOMEM;
goto free;
}
elt->vars = kcalloc(map->n_vars, sizeof(*elt->vars), GFP_KERNEL);
if (!elt->vars) {
err = -ENOMEM;
goto free;
}
elt->var_set = kcalloc(map->n_vars, sizeof(*elt->var_set), GFP_KERNEL);
if (!elt->var_set) {
err = -ENOMEM;
goto free;
}
tracing_map_elt_init_fields(elt);
if (map->ops && map->ops->elt_alloc) {
err = map->ops->elt_alloc(elt);
if (err)
goto free;
}
return elt;
free:
tracing_map_elt_free(elt);
return ERR_PTR(err);
}
static struct tracing_map_elt *get_free_elt(struct tracing_map *map)
{
struct tracing_map_elt *elt = NULL;
int idx;
idx = atomic_inc_return(&map->next_elt);
if (idx < map->max_elts) {
elt = *(TRACING_MAP_ELT(map->elts, idx));
if (map->ops && map->ops->elt_init)
map->ops->elt_init(elt);
}
return elt;
}
static void tracing_map_free_elts(struct tracing_map *map)
{
unsigned int i;
if (!map->elts)
return;
for (i = 0; i < map->max_elts; i++) {
tracing_map_elt_free(*(TRACING_MAP_ELT(map->elts, i)));
*(TRACING_MAP_ELT(map->elts, i)) = NULL;
}
tracing_map_array_free(map->elts);
map->elts = NULL;
}
static int tracing_map_alloc_elts(struct tracing_map *map)
{
unsigned int i;
map->elts = tracing_map_array_alloc(map->max_elts,
sizeof(struct tracing_map_elt *));
if (!map->elts)
return -ENOMEM;
for (i = 0; i < map->max_elts; i++) {
*(TRACING_MAP_ELT(map->elts, i)) = tracing_map_elt_alloc(map);
if (IS_ERR(*(TRACING_MAP_ELT(map->elts, i)))) {
*(TRACING_MAP_ELT(map->elts, i)) = NULL;
tracing_map_free_elts(map);
return -ENOMEM;
}
}
return 0;
}
static inline bool keys_match(void *key, void *test_key, unsigned key_size)
{
bool match = true;
if (memcmp(key, test_key, key_size))
match = false;
return match;
}
static inline struct tracing_map_elt *
__tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only)
{
u32 idx, key_hash, test_key;
int dup_try = 0;
struct tracing_map_entry *entry;
struct tracing_map_elt *val;
key_hash = jhash(key, map->key_size, 0);
if (key_hash == 0)
key_hash = 1;
idx = key_hash >> (32 - (map->map_bits + 1));
while (1) {
idx &= (map->map_size - 1);
entry = TRACING_MAP_ENTRY(map->map, idx);
test_key = entry->key;
if (test_key && test_key == key_hash) {
val = READ_ONCE(entry->val);
if (val &&
keys_match(key, val->key, map->key_size)) {
if (!lookup_only)
atomic64_inc(&map->hits);
return val;
} else if (unlikely(!val)) {
/*
* The key is present. But, val (pointer to elt
* struct) is still NULL. which means some other
* thread is in the process of inserting an
* element.
*
* On top of that, it's key_hash is same as the
* one being inserted right now. So, it's
* possible that the element has the same
* key as well.
*/
dup_try++;
if (dup_try > map->map_size) {
atomic64_inc(&map->drops);
break;
}
continue;
}
}
if (!test_key) {
if (lookup_only)
break;
if (!cmpxchg(&entry->key, 0, key_hash)) {
struct tracing_map_elt *elt;
elt = get_free_elt(map);
if (!elt) {
atomic64_inc(&map->drops);
entry->key = 0;
break;
}
memcpy(elt->key, key, map->key_size);
entry->val = elt;
atomic64_inc(&map->hits);
return entry->val;
} else {
/*
* cmpxchg() failed. Loop around once
* more to check what key was inserted.
*/
dup_try++;
continue;
}
}
idx++;
}
return NULL;
}
/**
* tracing_map_insert - Insert key and/or retrieve val from a tracing_map
* @map: The tracing_map to insert into
* @key: The key to insert
*
* Inserts a key into a tracing_map and creates and returns a new
* tracing_map_elt for it, or if the key has already been inserted by
* a previous call, returns the tracing_map_elt already associated
* with it. When the map was created, the number of elements to be
* allocated for the map was specified (internally maintained as
* 'max_elts' in struct tracing_map), and that number of
* tracing_map_elts was created by tracing_map_init(). This is the
* pre-allocated pool of tracing_map_elts that tracing_map_insert()
* will allocate from when adding new keys. Once that pool is
* exhausted, tracing_map_insert() is useless and will return NULL to
* signal that state. There are two user-visible tracing_map
* variables, 'hits' and 'drops', which are updated by this function.
* Every time an element is either successfully inserted or retrieved,
* the 'hits' value is incrememented. Every time an element insertion
* fails, the 'drops' value is incremented.
*
* This is a lock-free tracing map insertion function implementing a
* modified form of Cliff Click's basic insertion algorithm. It
* requires the table size be a power of two. To prevent any
* possibility of an infinite loop we always make the internal table
* size double the size of the requested table size (max_elts * 2).
* Likewise, we never reuse a slot or resize or delete elements - when
* we've reached max_elts entries, we simply return NULL once we've
* run out of entries. Readers can at any point in time traverse the
* tracing map and safely access the key/val pairs.
*
* Return: the tracing_map_elt pointer val associated with the key.
* If this was a newly inserted key, the val will be a newly allocated
* and associated tracing_map_elt pointer val. If the key wasn't
* found and the pool of tracing_map_elts has been exhausted, NULL is
* returned and no further insertions will succeed.
*/
struct tracing_map_elt *tracing_map_insert(struct tracing_map *map, void *key)
{
return __tracing_map_insert(map, key, false);
}
/**
* tracing_map_lookup - Retrieve val from a tracing_map
* @map: The tracing_map to perform the lookup on
* @key: The key to look up
*
* Looks up key in tracing_map and if found returns the matching
* tracing_map_elt. This is a lock-free lookup; see
* tracing_map_insert() for details on tracing_map and how it works.
* Every time an element is retrieved, the 'hits' value is
* incrememented. There is one user-visible tracing_map variable,
* 'hits', which is updated by this function. Every time an element
* is successfully retrieved, the 'hits' value is incrememented. The
* 'drops' value is never updated by this function.
*
* Return: the tracing_map_elt pointer val associated with the key.
* If the key wasn't found, NULL is returned.
*/
struct tracing_map_elt *tracing_map_lookup(struct tracing_map *map, void *key)
{
return __tracing_map_insert(map, key, true);
}
/**
* tracing_map_destroy - Destroy a tracing_map
* @map: The tracing_map to destroy
*
* Frees a tracing_map along with its associated array of
* tracing_map_elts.
*
* Callers should make sure there are no readers or writers actively
* reading or inserting into the map before calling this.
*/
void tracing_map_destroy(struct tracing_map *map)
{
if (!map)
return;
tracing_map_free_elts(map);
tracing_map_array_free(map->map);
kfree(map);
}
/**
* tracing_map_clear - Clear a tracing_map
* @map: The tracing_map to clear
*
* Resets the tracing map to a cleared or initial state. The
* tracing_map_elts are all cleared, and the array of struct
* tracing_map_entry is reset to an initialized state.
*
* Callers should make sure there are no writers actively inserting
* into the map before calling this.
*/
void tracing_map_clear(struct tracing_map *map)
{
unsigned int i;
atomic_set(&map->next_elt, -1);
atomic64_set(&map->hits, 0);
atomic64_set(&map->drops, 0);
tracing_map_array_clear(map->map);
for (i = 0; i < map->max_elts; i++)
tracing_map_elt_clear(*(TRACING_MAP_ELT(map->elts, i)));
}
static void set_sort_key(struct tracing_map *map,
struct tracing_map_sort_key *sort_key)
{
map->sort_key = *sort_key;
}
/**
* tracing_map_create - Create a lock-free map and element pool
* @map_bits: The size of the map (2 ** map_bits)
* @key_size: The size of the key for the map in bytes
* @ops: Optional client-defined tracing_map_ops instance
* @private_data: Client data associated with the map
*
* Creates and sets up a map to contain 2 ** map_bits number of
* elements (internally maintained as 'max_elts' in struct
* tracing_map). Before using, map fields should be added to the map
* with tracing_map_add_sum_field() and tracing_map_add_key_field().
* tracing_map_init() should then be called to allocate the array of
* tracing_map_elts, in order to avoid allocating anything in the map
* insertion path. The user-specified map size reflects the maximum
* number of elements that can be contained in the table requested by
* the user - internally we double that in order to keep the table
* sparse and keep collisions manageable.
*
* A tracing_map is a special-purpose map designed to aggregate or
* 'sum' one or more values associated with a specific object of type
* tracing_map_elt, which is attached by the map to a given key.
*
* tracing_map_create() sets up the map itself, and provides
* operations for inserting tracing_map_elts, but doesn't allocate the
* tracing_map_elts themselves, or provide a means for describing the
* keys or sums associated with the tracing_map_elts. All
* tracing_map_elts for a given map have the same set of sums and
* keys, which are defined by the client using the functions
* tracing_map_add_key_field() and tracing_map_add_sum_field(). Once
* the fields are defined, the pool of elements allocated for the map
* can be created, which occurs when the client code calls
* tracing_map_init().
*
* When tracing_map_init() returns, tracing_map_elt elements can be
* inserted into the map using tracing_map_insert(). When called,
* tracing_map_insert() grabs a free tracing_map_elt from the pool, or
* finds an existing match in the map and in either case returns it.
* The client can then use tracing_map_update_sum() and
* tracing_map_read_sum() to update or read a given sum field for the
* tracing_map_elt.
*
* The client can at any point retrieve and traverse the current set
* of inserted tracing_map_elts in a tracing_map, via
* tracing_map_sort_entries(). Sorting can be done on any field,
* including keys.
*
* See tracing_map.h for a description of tracing_map_ops.
*
* Return: the tracing_map pointer if successful, ERR_PTR if not.
*/
struct tracing_map *tracing_map_create(unsigned int map_bits,
unsigned int key_size,
const struct tracing_map_ops *ops,
void *private_data)
{
struct tracing_map *map;
unsigned int i;
if (map_bits < TRACING_MAP_BITS_MIN ||
map_bits > TRACING_MAP_BITS_MAX)
return ERR_PTR(-EINVAL);
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (!map)
return ERR_PTR(-ENOMEM);
map->map_bits = map_bits;
map->max_elts = (1 << map_bits);
atomic_set(&map->next_elt, -1);
map->map_size = (1 << (map_bits + 1));
map->ops = ops;
map->private_data = private_data;
map->map = tracing_map_array_alloc(map->map_size,
sizeof(struct tracing_map_entry));
if (!map->map)
goto free;
map->key_size = key_size;
for (i = 0; i < TRACING_MAP_KEYS_MAX; i++)
map->key_idx[i] = -1;
out:
return map;
free:
tracing_map_destroy(map);
map = ERR_PTR(-ENOMEM);
goto out;
}
/**
* tracing_map_init - Allocate and clear a map's tracing_map_elts
* @map: The tracing_map to initialize
*
* Allocates a clears a pool of tracing_map_elts equal to the
* user-specified size of 2 ** map_bits (internally maintained as
* 'max_elts' in struct tracing_map). Before using, the map fields
* should be added to the map with tracing_map_add_sum_field() and
* tracing_map_add_key_field(). tracing_map_init() should then be
* called to allocate the array of tracing_map_elts, in order to avoid
* allocating anything in the map insertion path. The user-specified
* map size reflects the max number of elements requested by the user
* - internally we double that in order to keep the table sparse and
* keep collisions manageable.
*
* See tracing_map.h for a description of tracing_map_ops.
*
* Return: the tracing_map pointer if successful, ERR_PTR if not.
*/
int tracing_map_init(struct tracing_map *map)
{
int err;
if (map->n_fields < 2)
return -EINVAL; /* need at least 1 key and 1 val */
err = tracing_map_alloc_elts(map);
if (err)
return err;
tracing_map_clear(map);
return err;
}
static int cmp_entries_dup(const struct tracing_map_sort_entry **a,
const struct tracing_map_sort_entry **b)
{
int ret = 0;
if (memcmp((*a)->key, (*b)->key, (*a)->elt->map->key_size))
ret = 1;
return ret;
}
static int cmp_entries_sum(const struct tracing_map_sort_entry **a,
const struct tracing_map_sort_entry **b)
{
const struct tracing_map_elt *elt_a, *elt_b;
struct tracing_map_sort_key *sort_key;
struct tracing_map_field *field;
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
elt_a = (*a)->elt;
elt_b = (*b)->elt;
sort_key = &elt_a->map->sort_key;
field = &elt_a->fields[sort_key->field_idx];
cmp_fn = field->cmp_fn;
val_a = &elt_a->fields[sort_key->field_idx].sum;
val_b = &elt_b->fields[sort_key->field_idx].sum;
ret = cmp_fn(val_a, val_b);
if (sort_key->descending)
ret = -ret;
return ret;
}
static int cmp_entries_key(const struct tracing_map_sort_entry **a,
const struct tracing_map_sort_entry **b)
{
const struct tracing_map_elt *elt_a, *elt_b;
struct tracing_map_sort_key *sort_key;
struct tracing_map_field *field;
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
elt_a = (*a)->elt;
elt_b = (*b)->elt;
sort_key = &elt_a->map->sort_key;
field = &elt_a->fields[sort_key->field_idx];
cmp_fn = field->cmp_fn;
val_a = elt_a->key + field->offset;
val_b = elt_b->key + field->offset;
ret = cmp_fn(val_a, val_b);
if (sort_key->descending)
ret = -ret;
return ret;
}
static void destroy_sort_entry(struct tracing_map_sort_entry *entry)
{
if (!entry)
return;
if (entry->elt_copied)
tracing_map_elt_free(entry->elt);
kfree(entry);
}
/**
* tracing_map_destroy_sort_entries - Destroy an array of sort entries
* @entries: The entries to destroy
* @n_entries: The number of entries in the array
*
* Destroy the elements returned by a tracing_map_sort_entries() call.
*/
void tracing_map_destroy_sort_entries(struct tracing_map_sort_entry **entries,
unsigned int n_entries)
{
unsigned int i;
for (i = 0; i < n_entries; i++)
destroy_sort_entry(entries[i]);
vfree(entries);
}
static struct tracing_map_sort_entry *
create_sort_entry(void *key, struct tracing_map_elt *elt)
{
struct tracing_map_sort_entry *sort_entry;
sort_entry = kzalloc(sizeof(*sort_entry), GFP_KERNEL);
if (!sort_entry)
return NULL;
sort_entry->key = key;
sort_entry->elt = elt;
return sort_entry;
}
static void detect_dups(struct tracing_map_sort_entry **sort_entries,
int n_entries, unsigned int key_size)
{
unsigned int dups = 0, total_dups = 0;
int i;
void *key;
if (n_entries < 2)
return;
sort(sort_entries, n_entries, sizeof(struct tracing_map_sort_entry *),
(int (*)(const void *, const void *))cmp_entries_dup, NULL);
key = sort_entries[0]->key;
for (i = 1; i < n_entries; i++) {
if (!memcmp(sort_entries[i]->key, key, key_size)) {
dups++; total_dups++;
continue;
}
key = sort_entries[i]->key;
dups = 0;
}
WARN_ONCE(total_dups > 0,
"Duplicates detected: %d\n", total_dups);
}
static bool is_key(struct tracing_map *map, unsigned int field_idx)
{
unsigned int i;
for (i = 0; i < map->n_keys; i++)
if (map->key_idx[i] == field_idx)
return true;
return false;
}
static void sort_secondary(struct tracing_map *map,
const struct tracing_map_sort_entry **entries,
unsigned int n_entries,
struct tracing_map_sort_key *primary_key,
struct tracing_map_sort_key *secondary_key)
{
int (*primary_fn)(const struct tracing_map_sort_entry **,
const struct tracing_map_sort_entry **);
int (*secondary_fn)(const struct tracing_map_sort_entry **,
const struct tracing_map_sort_entry **);
unsigned i, start = 0, n_sub = 1;
if (is_key(map, primary_key->field_idx))
primary_fn = cmp_entries_key;
else
primary_fn = cmp_entries_sum;
if (is_key(map, secondary_key->field_idx))
secondary_fn = cmp_entries_key;
else
secondary_fn = cmp_entries_sum;
for (i = 0; i < n_entries - 1; i++) {
const struct tracing_map_sort_entry **a = &entries[i];
const struct tracing_map_sort_entry **b = &entries[i + 1];
if (primary_fn(a, b) == 0) {
n_sub++;
if (i < n_entries - 2)
continue;
}
if (n_sub < 2) {
start = i + 1;
n_sub = 1;
continue;
}
set_sort_key(map, secondary_key);
sort(&entries[start], n_sub,
sizeof(struct tracing_map_sort_entry *),
(int (*)(const void *, const void *))secondary_fn, NULL);
set_sort_key(map, primary_key);
start = i + 1;
n_sub = 1;
}
}
/**
* tracing_map_sort_entries - Sort the current set of tracing_map_elts in a map
* @map: The tracing_map
* @sort_key: The sort key to use for sorting
* @sort_entries: outval: pointer to allocated and sorted array of entries
*
* tracing_map_sort_entries() sorts the current set of entries in the
* map and returns the list of tracing_map_sort_entries containing
* them to the client in the sort_entries param. The client can
* access the struct tracing_map_elt element of interest directly as
* the 'elt' field of a returned struct tracing_map_sort_entry object.
*
* The sort_key has only two fields: idx and descending. 'idx' refers
* to the index of the field added via tracing_map_add_sum_field() or
* tracing_map_add_key_field() when the tracing_map was initialized.
* 'descending' is a flag that if set reverses the sort order, which
* by default is ascending.
*
* The client should not hold on to the returned array but should use
* it and call tracing_map_destroy_sort_entries() when done.
*
* Return: the number of sort_entries in the struct tracing_map_sort_entry
* array, negative on error
*/
int tracing_map_sort_entries(struct tracing_map *map,
struct tracing_map_sort_key *sort_keys,
unsigned int n_sort_keys,
struct tracing_map_sort_entry ***sort_entries)
{
int (*cmp_entries_fn)(const struct tracing_map_sort_entry **,
const struct tracing_map_sort_entry **);
struct tracing_map_sort_entry *sort_entry, **entries;
int i, n_entries, ret;
entries = vmalloc(array_size(sizeof(sort_entry), map->max_elts));
if (!entries)
return -ENOMEM;
for (i = 0, n_entries = 0; i < map->map_size; i++) {
struct tracing_map_entry *entry;
entry = TRACING_MAP_ENTRY(map->map, i);
if (!entry->key || !entry->val)
continue;
entries[n_entries] = create_sort_entry(entry->val->key,
entry->val);
if (!entries[n_entries++]) {
ret = -ENOMEM;
goto free;
}
}
if (n_entries == 0) {
ret = 0;
goto free;
}
if (n_entries == 1) {
*sort_entries = entries;
return 1;
}
detect_dups(entries, n_entries, map->key_size);
if (is_key(map, sort_keys[0].field_idx))
cmp_entries_fn = cmp_entries_key;
else
cmp_entries_fn = cmp_entries_sum;
set_sort_key(map, &sort_keys[0]);
sort(entries, n_entries, sizeof(struct tracing_map_sort_entry *),
(int (*)(const void *, const void *))cmp_entries_fn, NULL);
if (n_sort_keys > 1)
sort_secondary(map,
(const struct tracing_map_sort_entry **)entries,
n_entries,
&sort_keys[0],
&sort_keys[1]);
*sort_entries = entries;
return n_entries;
free:
tracing_map_destroy_sort_entries(entries, n_entries);
return ret;
}
Reference in New Issue View Git Blame Copy Permalink