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1
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forked from pool/qemu
qemu/0022-qemu-cvs-alsa_mmap.patch

49 lines
1.6 KiB
Diff

From 3ea2fa480d730990c427d4a2924168f2b6f42dba Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Tue, 14 Apr 2009 16:24:15 +0200
Subject: [PATCH 22/32] qemu-cvs-alsa_mmap
Hack to prevent ALSA from using mmap() interface to simplify emulation.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Ulrich Hecht <uli@suse.de>
---
linux-user/mmap.c | 14 ++++++++++++++
1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 1e8cc38..1e5ba51 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -380,6 +380,9 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
}
}
+#define SNDRV_PCM_MMAP_OFFSET_STATUS 0x80000000
+#define SNDRV_PCM_MMAP_OFFSET_CONTROL 0x81000000
+
/* NOTE: all the constants are the HOST ones */
abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
int flags, int fd, abi_ulong offset)
@@ -415,6 +418,17 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
}
#endif
+ /* Alsa tries to communcate with the kernel via mmap. This usually
+ * is a good idea when user- and kernelspace are running on the
+ * same architecture but does not work out when not. To make alsa
+ * not to use mmap, we can just have it fail on the mmap calls that
+ * would initiate this.
+ */
+ if(offset == SNDRV_PCM_MMAP_OFFSET_STATUS || offset == SNDRV_PCM_MMAP_OFFSET_CONTROL) {
+ errno = EINVAL;
+ return -1;
+ }
+
if (offset & ~TARGET_PAGE_MASK) {
errno = EINVAL;
goto fail;
--
1.6.0.2