fix lock-up issues in lzma pcomp support in 2.6.30 (used in squashfs). thanks to jeff hansen for the patch

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@16886 3c298f89-4303-0410-b956-a3cf2f4a3e73
master
Felix Fietkau 2009-07-18 00:36:13 +00:00
parent 916ce4ba2f
commit b9e97b34b9
1 changed files with 34 additions and 23 deletions

View File

@ -1,6 +1,6 @@
--- /dev/null
+++ b/crypto/unlzma.c
@@ -0,0 +1,710 @@
@@ -0,0 +1,721 @@
+/*
+ * LZMA uncompresion module for pcomp
+ * Copyright (C) 2009 Felix Fietkau <nbd@openwrt.org>
@ -69,6 +69,7 @@
+ u8 previous_byte;
+ ssize_t pos;
+ struct unlzma_buffer *head;
+ int buf_full;
+
+ /* cstate */
+ int state;
@ -87,11 +88,32 @@
+}
+
+static void
+get_buffer(struct unlzma_ctx *ctx)
+{
+ struct unlzma_buffer *bh;
+
+ bh = kzalloc(sizeof(struct unlzma_buffer), GFP_KERNEL);
+ 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;
+}
+
+static void
+unlzma_request_buffer(struct unlzma_ctx *ctx, int *avail)
+{
+ mutex_unlock(&ctx->mutex);
+ wait_event(ctx->next_req, unlzma_should_stop(ctx) || (*avail > 0));
+ mutex_lock(&ctx->mutex);
+ do {
+ mutex_unlock(&ctx->mutex);
+ if (wait_event_interruptible(ctx->next_req,
+ unlzma_should_stop(ctx) || (*avail > 0)))
+ schedule();
+ mutex_lock(&ctx->mutex);
+ } while (*avail <= 0 && !unlzma_should_stop(ctx));
+
+ if (!unlzma_should_stop(ctx) && ctx->buf_full)
+ get_buffer(ctx);
+}
+
+static u8
@ -196,36 +218,20 @@
+
+ while (bh->offset > pos) {
+ bh = bh->last;
+ if (!bh)
+ return 0;
+ BUG_ON(!bh);
+ }
+
+ pos -= bh->offset;
+ if (pos > bh->size)
+ return 0;
+ BUG_ON(pos >= bh->size);
+
+ return bh->ptr[pos];
+}
+
+static void
+get_buffer(struct unlzma_ctx *ctx)
+{
+ struct unlzma_buffer *bh;
+
+ bh = kzalloc(sizeof(struct unlzma_buffer), GFP_KERNEL);
+ bh->ptr = ctx->next_out;
+ bh->offset = ctx->pos;
+ bh->last = ctx->head;
+ bh->size = ctx->avail_out;
+ ctx->head = bh;
+}
+
+static void
+write_byte(struct unlzma_ctx *ctx, u8 byte)
+{
+ if (unlikely(ctx->avail_out <= 0)) {
+ unlzma_request_buffer(ctx, &ctx->avail_out);
+ get_buffer(ctx);
+ }
+
+ if (!ctx->avail_out)
@ -234,6 +240,8 @@
+ ctx->previous_byte = byte;
+ *(ctx->next_out++) = byte;
+ ctx->avail_out--;
+ if (ctx->avail_out == 0)
+ ctx->buf_full = 1;
+ ctx->pos++;
+}
+
@ -489,7 +497,8 @@
+ if (ctx->workspace_size < num_probs * sizeof(*p)) {
+ if (ctx->workspace)
+ vfree(ctx->workspace);
+ ctx->workspace = vmalloc(num_probs * sizeof(*p));
+ ctx->workspace_size = num_probs * sizeof(*p);
+ ctx->workspace = vmalloc(ctx->workspace_size);
+ }
+ p = (u16 *) ctx->workspace;
+ if (!p)
@ -652,6 +661,8 @@
+ req->avail_in = ctx->avail_in;
+ req->next_out = ctx->next_out;
+ req->avail_out = ctx->avail_out;
+ ctx->next_in = 0;
+ ctx->avail_in = 0;
+ pos = ctx->pos - pos;
+
+out: