From 8dc126f05ef5f8d0105d5d1b77493a27df8b4e30 Mon Sep 17 00:00:00 2001 From: Ulrich Hecht Date: Tue, 14 Apr 2009 16:24:15 +0200 Subject: [PATCH 05/16] qemu-cvs-alsa_mmap Hack to prevent ALSA from using mmap() interface to simplify emulation. Signed-off-by: Ulrich Hecht --- 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 144fb7c..1ea202b 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -328,6 +328,9 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size) return h2g(ptr); } +#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) @@ -363,6 +366,17 @@ 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; -- 1.6.4.2