Revision 91874ecf32e41b5d86a4cb9d60e0bee50d828058 authored by Dmitry Safonov on 05 August 2018, 00:35:53 UTC, committed by David S. Miller on 05 August 2018, 00:52:51 UTC
It's legal to have 64 groups for netlink_sock. As user-supplied nladdr->nl_groups is __u32, it's possible to subscribe only to first 32 groups. The check for correctness of .bind() userspace supplied parameter is done by applying mask made from ngroups shift. Which broke Android as they have 64 groups and the shift for mask resulted in an overflow. Fixes: 61f4b23769f0 ("netlink: Don't shift with UB on nlk->ngroups") Cc: "David S. Miller" <davem@davemloft.net> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: netdev@vger.kernel.org Cc: stable@vger.kernel.org Reported-and-Tested-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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percpu-stats.c
/*
* mm/percpu-debug.c
*
* Copyright (C) 2017 Facebook Inc.
* Copyright (C) 2017 Dennis Zhou <dennisz@fb.com>
*
* This file is released under the GPLv2.
*
* Prints statistics about the percpu allocator and backing chunks.
*/
#include <linux/debugfs.h>
#include <linux/list.h>
#include <linux/percpu.h>
#include <linux/seq_file.h>
#include <linux/sort.h>
#include <linux/vmalloc.h>
#include "percpu-internal.h"
#define P(X, Y) \
seq_printf(m, " %-20s: %12lld\n", X, (long long int)Y)
struct percpu_stats pcpu_stats;
struct pcpu_alloc_info pcpu_stats_ai;
static int cmpint(const void *a, const void *b)
{
return *(int *)a - *(int *)b;
}
/*
* Iterates over all chunks to find the max nr_alloc entries.
*/
static int find_max_nr_alloc(void)
{
struct pcpu_chunk *chunk;
int slot, max_nr_alloc;
max_nr_alloc = 0;
for (slot = 0; slot < pcpu_nr_slots; slot++)
list_for_each_entry(chunk, &pcpu_slot[slot], list)
max_nr_alloc = max(max_nr_alloc, chunk->nr_alloc);
return max_nr_alloc;
}
/*
* Prints out chunk state. Fragmentation is considered between
* the beginning of the chunk to the last allocation.
*
* All statistics are in bytes unless stated otherwise.
*/
static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk,
int *buffer)
{
int i, last_alloc, as_len, start, end;
int *alloc_sizes, *p;
/* statistics */
int sum_frag = 0, max_frag = 0;
int cur_min_alloc = 0, cur_med_alloc = 0, cur_max_alloc = 0;
alloc_sizes = buffer;
/*
* find_last_bit returns the start value if nothing found.
* Therefore, we must determine if it is a failure of find_last_bit
* and set the appropriate value.
*/
last_alloc = find_last_bit(chunk->alloc_map,
pcpu_chunk_map_bits(chunk) -
chunk->end_offset / PCPU_MIN_ALLOC_SIZE - 1);
last_alloc = test_bit(last_alloc, chunk->alloc_map) ?
last_alloc + 1 : 0;
as_len = 0;
start = chunk->start_offset / PCPU_MIN_ALLOC_SIZE;
/*
* If a bit is set in the allocation map, the bound_map identifies
* where the allocation ends. If the allocation is not set, the
* bound_map does not identify free areas as it is only kept accurate
* on allocation, not free.
*
* Positive values are allocations and negative values are free
* fragments.
*/
while (start < last_alloc) {
if (test_bit(start, chunk->alloc_map)) {
end = find_next_bit(chunk->bound_map, last_alloc,
start + 1);
alloc_sizes[as_len] = 1;
} else {
end = find_next_bit(chunk->alloc_map, last_alloc,
start + 1);
alloc_sizes[as_len] = -1;
}
alloc_sizes[as_len++] *= (end - start) * PCPU_MIN_ALLOC_SIZE;
start = end;
}
/*
* The negative values are free fragments and thus sorting gives the
* free fragments at the beginning in largest first order.
*/
if (as_len > 0) {
sort(alloc_sizes, as_len, sizeof(int), cmpint, NULL);
/* iterate through the unallocated fragments */
for (i = 0, p = alloc_sizes; *p < 0 && i < as_len; i++, p++) {
sum_frag -= *p;
max_frag = max(max_frag, -1 * (*p));
}
cur_min_alloc = alloc_sizes[i];
cur_med_alloc = alloc_sizes[(i + as_len - 1) / 2];
cur_max_alloc = alloc_sizes[as_len - 1];
}
P("nr_alloc", chunk->nr_alloc);
P("max_alloc_size", chunk->max_alloc_size);
P("empty_pop_pages", chunk->nr_empty_pop_pages);
P("first_bit", chunk->first_bit);
P("free_bytes", chunk->free_bytes);
P("contig_bytes", chunk->contig_bits * PCPU_MIN_ALLOC_SIZE);
P("sum_frag", sum_frag);
P("max_frag", max_frag);
P("cur_min_alloc", cur_min_alloc);
P("cur_med_alloc", cur_med_alloc);
P("cur_max_alloc", cur_max_alloc);
seq_putc(m, '\n');
}
static int percpu_stats_show(struct seq_file *m, void *v)
{
struct pcpu_chunk *chunk;
int slot, max_nr_alloc;
int *buffer;
alloc_buffer:
spin_lock_irq(&pcpu_lock);
max_nr_alloc = find_max_nr_alloc();
spin_unlock_irq(&pcpu_lock);
/* there can be at most this many free and allocated fragments */
buffer = vmalloc(array_size(sizeof(int), (2 * max_nr_alloc + 1)));
if (!buffer)
return -ENOMEM;
spin_lock_irq(&pcpu_lock);
/* if the buffer allocated earlier is too small */
if (max_nr_alloc < find_max_nr_alloc()) {
spin_unlock_irq(&pcpu_lock);
vfree(buffer);
goto alloc_buffer;
}
#define PL(X) \
seq_printf(m, " %-20s: %12lld\n", #X, (long long int)pcpu_stats_ai.X)
seq_printf(m,
"Percpu Memory Statistics\n"
"Allocation Info:\n"
"----------------------------------------\n");
PL(unit_size);
PL(static_size);
PL(reserved_size);
PL(dyn_size);
PL(atom_size);
PL(alloc_size);
seq_putc(m, '\n');
#undef PL
#define PU(X) \
seq_printf(m, " %-20s: %12llu\n", #X, (unsigned long long)pcpu_stats.X)
seq_printf(m,
"Global Stats:\n"
"----------------------------------------\n");
PU(nr_alloc);
PU(nr_dealloc);
PU(nr_cur_alloc);
PU(nr_max_alloc);
PU(nr_chunks);
PU(nr_max_chunks);
PU(min_alloc_size);
PU(max_alloc_size);
P("empty_pop_pages", pcpu_nr_empty_pop_pages);
seq_putc(m, '\n');
#undef PU
seq_printf(m,
"Per Chunk Stats:\n"
"----------------------------------------\n");
if (pcpu_reserved_chunk) {
seq_puts(m, "Chunk: <- Reserved Chunk\n");
chunk_map_stats(m, pcpu_reserved_chunk, buffer);
}
for (slot = 0; slot < pcpu_nr_slots; slot++) {
list_for_each_entry(chunk, &pcpu_slot[slot], list) {
if (chunk == pcpu_first_chunk) {
seq_puts(m, "Chunk: <- First Chunk\n");
chunk_map_stats(m, chunk, buffer);
} else {
seq_puts(m, "Chunk:\n");
chunk_map_stats(m, chunk, buffer);
}
}
}
spin_unlock_irq(&pcpu_lock);
vfree(buffer);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(percpu_stats);
static int __init init_percpu_stats_debugfs(void)
{
debugfs_create_file("percpu_stats", 0444, NULL, NULL,
&percpu_stats_fops);
return 0;
}
late_initcall(init_percpu_stats_debugfs);
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