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Protect the move operation of buflib against IRQs.

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This makes accessing the buffers with core_get_data() from
interrupt context safe, other buflib functions aren't really safe (yet).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30736 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Thomas Martitz 2011-10-09 12:27:35 +00:00
parent 227c7af9b3
commit aed39dbbaf
1 changed files with 10 additions and 0 deletions
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10
firmware/buflib.c
View file

@ -206,16 +206,26 @@ move_block(struct buflib_context* ctx, union buflib_data* block, int shift)
handle, shift, shift*sizeof(union buflib_data));
new_block = block + shift;
new_start = tmp->alloc + shift*sizeof(union buflib_data);
/* disable IRQs to make accessing the buffer from interrupt context safe. */
/* protect the move callback, as a cached global pointer might be updated
* in it. and protect "tmp->alloc = new_start" for buflib_get_data() */
disable_irq();
/* call the callback before moving */
if (ops)
{
if (ops->move_callback(handle, tmp->alloc, new_start)
== BUFLIB_CB_CANNOT_MOVE)
{
enable_irq();
return false;
}
}
tmp->alloc = new_start; /* update handle table */
memmove(new_block, block, block->val * sizeof(union buflib_data));
enable_irq();
return true;
}