unlzma: fix a race condition and add some optimizations to improve performance also make peek_old_byte errors non-fatal

SVN-Revision: 17678
This commit is contained in:
Felix Fietkau 2009-09-22 18:00:28 +00:00
parent 392e45ef09
commit 0754070949
2 changed files with 124 additions and 36 deletions

View file

@ -1,6 +1,6 @@
--- /dev/null
+++ b/crypto/unlzma.c
@@ -0,0 +1,748 @@
@@ -0,0 +1,772 @@
+/*
+ * LZMA uncompresion module for pcomp
+ * Copyright (C) 2009 Felix Fietkau <nbd@openwrt.org>
@ -50,7 +50,9 @@
+struct unlzma_ctx {
+ struct task_struct *thread;
+ wait_queue_head_t next_req;
+ wait_queue_head_t req_done;
+ struct mutex mutex;
+ bool waiting;
+ bool active;
+ bool cancel;
+
@ -106,7 +108,9 @@
+unlzma_request_buffer(struct unlzma_ctx *ctx, int *avail)
+{
+ do {
+ ctx->waiting = true;
+ mutex_unlock(&ctx->mutex);
+ wake_up(&ctx->req_done);
+ if (wait_event_interruptible(ctx->next_req,
+ unlzma_should_stop(ctx) || (*avail > 0)))
+ schedule();
@ -213,22 +217,35 @@
+ int i = ctx->n_buffers;
+ u32 pos;
+
+ BUG_ON(!ctx->n_buffers);
+ pos = ctx->pos - offs;
+ if (pos >= ctx->dict_size) {
+ pos = (~pos % ctx->dict_size);
+ if (!ctx->n_buffers) {
+ printk(KERN_ERR "unlzma/%s: no buffer\n", __func__);
+ goto error;
+ }
+
+ pos = ctx->pos - offs;
+ if (unlikely(pos >= ctx->dict_size))
+ pos = ~pos & (ctx->dict_size - 1);
+
+ while (bh->offset > pos) {
+ bh--;
+ i--;
+ BUG_ON(!i);
+ if (!i) {
+ printk(KERN_ERR "unlzma/%s: position %d out of range\n", __func__, pos);
+ goto error;
+ }
+ }
+
+ pos -= bh->offset;
+ BUG_ON(pos >= bh->size);
+ if (pos >= bh->size) {
+ printk(KERN_ERR "unlzma/%s: position %d out of range\n", __func__, pos);
+ goto error;
+ }
+
+ return bh->ptr[pos];
+
+error:
+ ctx->cancel = true;
+ return 0;
+}
+
+static void
@ -635,8 +652,10 @@
+ if (!ctx->buffers)
+ return -ENOMEM;
+
+ ctx->waiting = false;
+ mutex_init(&ctx->mutex);
+ init_waitqueue_head(&ctx->next_req);
+ init_waitqueue_head(&ctx->req_done);
+ ctx->thread = kthread_run(unlzma_thread, ctx, "unlzma/%d", instance++);
+ if (IS_ERR(ctx->thread)) {
+ ret = PTR_ERR(ctx->thread);
@ -649,21 +668,22 @@
+static int
+unlzma_decompress_init(struct crypto_pcomp *tfm)
+{
+ struct unlzma_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
+
+ ctx->pos = 0;
+ return 0;
+}
+
+static void
+unlzma_wait_complete(struct unlzma_ctx *ctx, bool finish)
+{
+ DEFINE_WAIT(__wait);
+
+ do {
+ mutex_unlock(&ctx->mutex);
+ wake_up(&ctx->next_req);
+ prepare_to_wait(&ctx->req_done, &__wait, TASK_INTERRUPTIBLE);
+ mutex_unlock(&ctx->mutex);
+ schedule();
+ mutex_lock(&ctx->mutex);
+ } while (ctx->active && (ctx->avail_in > 0) && (ctx->avail_out > 0));
+ } while (!ctx->waiting && ctx->active);
+ finish_wait(&ctx->req_done, &__wait);
+}
+
+static int
@ -677,6 +697,7 @@
+ goto out;
+
+ pos = ctx->pos;
+ ctx->waiting = false;
+ ctx->next_in = req->next_in;
+ ctx->avail_in = req->avail_in;
+ ctx->next_out = req->next_out;
@ -694,6 +715,9 @@
+
+out:
+ mutex_unlock(&ctx->mutex);
+ if (ctx->cancel)
+ return -EINVAL;
+
+ return pos;
+}
+

View file

@ -1,6 +1,6 @@
--- /dev/null
+++ b/crypto/unlzma.c
@@ -0,0 +1,723 @@
@@ -0,0 +1,772 @@
+/*
+ * LZMA uncompresion module for pcomp
+ * Copyright (C) 2009 Felix Fietkau <nbd@openwrt.org>
@ -36,12 +36,12 @@
+#include <linux/kthread.h>
+
+#include <crypto/internal/compress.h>
+#include <net/netlink.h>
+#include "unlzma.h"
+
+static int instance = 0;
+
+struct unlzma_buffer {
+ struct unlzma_buffer *last;
+ int offset;
+ int size;
+ u8 *ptr;
@ -50,7 +50,9 @@
+struct unlzma_ctx {
+ struct task_struct *thread;
+ wait_queue_head_t next_req;
+ wait_queue_head_t req_done;
+ struct mutex mutex;
+ bool waiting;
+ bool active;
+ bool cancel;
+
@ -68,8 +70,10 @@
+ /* writer state */
+ u8 previous_byte;
+ ssize_t pos;
+ struct unlzma_buffer *head;
+ int buf_full;
+ int n_buffers;
+ int buffers_max;
+ struct unlzma_buffer *buffers;
+
+ /* cstate */
+ int state;
@ -92,12 +96,11 @@
+{
+ struct unlzma_buffer *bh;
+
+ bh = kzalloc(sizeof(struct unlzma_buffer), GFP_KERNEL);
+ BUG_ON(ctx->n_buffers >= ctx->buffers_max);
+ bh = &ctx->buffers[ctx->n_buffers++];
+ bh->ptr = ctx->next_out;
+ bh->offset = ctx->pos;
+ bh->last = ctx->head;
+ bh->size = ctx->avail_out;
+ ctx->head = bh;
+ ctx->buf_full = 0;
+}
+
@ -105,7 +108,9 @@
+unlzma_request_buffer(struct unlzma_ctx *ctx, int *avail)
+{
+ do {
+ ctx->waiting = true;
+ mutex_unlock(&ctx->mutex);
+ wake_up(&ctx->req_done);
+ if (wait_event_interruptible(ctx->next_req,
+ unlzma_should_stop(ctx) || (*avail > 0)))
+ schedule();
@ -208,23 +213,39 @@
+static u8
+peek_old_byte(struct unlzma_ctx *ctx, u32 offs)
+{
+ struct unlzma_buffer *bh = ctx->head;
+ struct unlzma_buffer *bh = &ctx->buffers[ctx->n_buffers - 1];
+ int i = ctx->n_buffers;
+ u32 pos;
+
+ pos = ctx->pos - offs;
+ if (pos >= ctx->dict_size) {
+ pos = (~pos % ctx->dict_size);
+ if (!ctx->n_buffers) {
+ printk(KERN_ERR "unlzma/%s: no buffer\n", __func__);
+ goto error;
+ }
+
+ pos = ctx->pos - offs;
+ if (unlikely(pos >= ctx->dict_size))
+ pos = ~pos & (ctx->dict_size - 1);
+
+ while (bh->offset > pos) {
+ bh = bh->last;
+ BUG_ON(!bh);
+ bh--;
+ i--;
+ if (!i) {
+ printk(KERN_ERR "unlzma/%s: position %d out of range\n", __func__, pos);
+ goto error;
+ }
+ }
+
+ pos -= bh->offset;
+ BUG_ON(pos >= bh->size);
+ if (pos >= bh->size) {
+ printk(KERN_ERR "unlzma/%s: position %d out of range\n", __func__, pos);
+ goto error;
+ }
+
+ return bh->ptr[pos];
+
+error:
+ ctx->cancel = true;
+ return 0;
+}
+
+static void
@ -460,6 +481,7 @@
+ hdr_buf[i] = rc_read(ctx);
+ }
+
+ ctx->n_buffers = 0;
+ ctx->pos = 0;
+ get_buffer(ctx);
+ ctx->active = true;
@ -554,11 +576,6 @@
+ unlzma_reset_buf(ctx);
+ ctx->cancel = false;
+ ctx->active = false;
+ while (ctx->head) {
+ struct unlzma_buffer *bh = ctx->head;
+ ctx->head = bh->last;
+ kfree(bh);
+ }
+ } while (!kthread_should_stop());
+ mutex_unlock(&ctx->mutex);
+ return 0;
@ -598,6 +615,10 @@
+ unlzma_cancel(ctx);
+ kthread_stop(ctx->thread);
+ ctx->thread = NULL;
+ if (ctx->buffers)
+ kfree(ctx->buffers);
+ ctx->buffers_max = 0;
+ ctx->buffers = NULL;
+ }
+}
+
@ -605,13 +626,36 @@
+unlzma_decompress_setup(struct crypto_pcomp *tfm, void *p, unsigned int len)
+{
+ struct unlzma_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
+ struct nlattr *tb[UNLZMA_DECOMP_MAX + 1];
+ int ret = 0;
+
+ if (ctx->thread)
+ return 0;
+ return -EINVAL;
+
+ if (!p)
+ return -EINVAL;
+
+ ret = nla_parse(tb, UNLZMA_DECOMP_MAX, p, len, NULL);
+ if (!tb[UNLZMA_DECOMP_OUT_BUFFERS])
+ return -EINVAL;
+
+ if (ctx->buffers_max && (ctx->buffers_max <
+ nla_get_u32(tb[UNLZMA_DECOMP_OUT_BUFFERS]))) {
+ kfree(ctx->buffers);
+ ctx->buffers_max = 0;
+ ctx->buffers = NULL;
+ }
+ if (!ctx->buffers) {
+ ctx->buffers_max = nla_get_u32(tb[UNLZMA_DECOMP_OUT_BUFFERS]);
+ ctx->buffers = kzalloc(sizeof(struct unlzma_buffer) * ctx->buffers_max, GFP_KERNEL);
+ }
+ if (!ctx->buffers)
+ return -ENOMEM;
+
+ ctx->waiting = false;
+ mutex_init(&ctx->mutex);
+ init_waitqueue_head(&ctx->next_req);
+ init_waitqueue_head(&ctx->req_done);
+ ctx->thread = kthread_run(unlzma_thread, ctx, "unlzma/%d", instance++);
+ if (IS_ERR(ctx->thread)) {
+ ret = PTR_ERR(ctx->thread);
@ -624,21 +668,22 @@
+static int
+unlzma_decompress_init(struct crypto_pcomp *tfm)
+{
+ struct unlzma_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
+
+ ctx->pos = 0;
+ return 0;
+}
+
+static void
+unlzma_wait_complete(struct unlzma_ctx *ctx, bool finish)
+{
+ DEFINE_WAIT(__wait);
+
+ do {
+ mutex_unlock(&ctx->mutex);
+ wake_up(&ctx->next_req);
+ prepare_to_wait(&ctx->req_done, &__wait, TASK_INTERRUPTIBLE);
+ mutex_unlock(&ctx->mutex);
+ schedule();
+ mutex_lock(&ctx->mutex);
+ } while (ctx->active && (ctx->avail_in > 0) && (ctx->avail_out > 0));
+ } while (!ctx->waiting && ctx->active);
+ finish_wait(&ctx->req_done, &__wait);
+}
+
+static int
@ -652,6 +697,7 @@
+ goto out;
+
+ pos = ctx->pos;
+ ctx->waiting = false;
+ ctx->next_in = req->next_in;
+ ctx->avail_in = req->avail_in;
+ ctx->next_out = req->next_out;
@ -669,6 +715,9 @@
+
+out:
+ mutex_unlock(&ctx->mutex);
+ if (ctx->cancel)
+ return -EINVAL;
+
+ return pos;
+}
+
@ -832,3 +881,18 @@
+#define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
+
+#endif
--- a/include/crypto/compress.h
+++ b/include/crypto/compress.h
@@ -49,6 +49,12 @@ enum zlib_decomp_params {
#define ZLIB_DECOMP_MAX (__ZLIB_DECOMP_MAX - 1)
+enum unlzma_decomp_params {
+ UNLZMA_DECOMP_OUT_BUFFERS = 1, /* naximum number of output buffers */
+ __UNLZMA_DECOMP_MAX,
+};
+#define UNLZMA_DECOMP_MAX (__UNLZMA_DECOMP_MAX - 1)
+
struct crypto_pcomp {
struct crypto_tfm base;