From: Felipe Contreras Date: Sat, 12 Mar 2011 00:29:06 +0000 (-0600) Subject: staging: tidspbridge: protect dmm_map properly X-Git-Tag: v2.6.38.1~49 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9d0a3d6acaca7004f2800d50eb44ccaca4257aee;p=users%2Fdwmw2%2Flinux.git staging: tidspbridge: protect dmm_map properly commit ab42abf33a3efdf754710a0a513c00c40854cd61 upstream. We need to protect not only the dmm_map list, but the individual map_obj's, otherwise, we might be building the scatter-gather list with garbage. So, use the existing proc_lock for that. I observed race conditions which caused kernel panics while running stress tests, also, Tuomas Kulve found it happening quite often in Gumstix Over. This patch fixes those. Cc: Tuomas Kulve Signed-off-by: Felipe Contreras Signed-off-by: Omar Ramirez Luna Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/tidspbridge/rmgr/proc.c b/drivers/staging/tidspbridge/rmgr/proc.c index b47d7aa747b1d..e2fe165bd797b 100644 --- a/drivers/staging/tidspbridge/rmgr/proc.c +++ b/drivers/staging/tidspbridge/rmgr/proc.c @@ -781,12 +781,14 @@ int proc_begin_dma(void *hprocessor, void *pmpu_addr, u32 ul_size, (u32)pmpu_addr, ul_size, dir); + mutex_lock(&proc_lock); + /* find requested memory are in cached mapping information */ map_obj = find_containing_mapping(pr_ctxt, (u32) pmpu_addr, ul_size); if (!map_obj) { pr_err("%s: find_containing_mapping failed\n", __func__); status = -EFAULT; - goto err_out; + goto no_map; } if (memory_give_ownership(map_obj, (u32) pmpu_addr, ul_size, dir)) { @@ -795,6 +797,8 @@ int proc_begin_dma(void *hprocessor, void *pmpu_addr, u32 ul_size, status = -EFAULT; } +no_map: + mutex_unlock(&proc_lock); err_out: return status; @@ -819,21 +823,24 @@ int proc_end_dma(void *hprocessor, void *pmpu_addr, u32 ul_size, (u32)pmpu_addr, ul_size, dir); + mutex_lock(&proc_lock); + /* find requested memory are in cached mapping information */ map_obj = find_containing_mapping(pr_ctxt, (u32) pmpu_addr, ul_size); if (!map_obj) { pr_err("%s: find_containing_mapping failed\n", __func__); status = -EFAULT; - goto err_out; + goto no_map; } if (memory_regain_ownership(map_obj, (u32) pmpu_addr, ul_size, dir)) { pr_err("%s: InValid address parameters %p %x\n", __func__, pmpu_addr, ul_size); status = -EFAULT; - goto err_out; } +no_map: + mutex_unlock(&proc_lock); err_out: return status; } @@ -1726,9 +1733,8 @@ int proc_un_map(void *hprocessor, void *map_addr, (p_proc_object->hbridge_context, va_align, size_align); } - mutex_unlock(&proc_lock); if (status) - goto func_end; + goto unmap_failed; /* * A successful unmap should be followed by removal of map_obj @@ -1737,6 +1743,9 @@ int proc_un_map(void *hprocessor, void *map_addr, */ remove_mapping_information(pr_ctxt, (u32) map_addr, size_align); +unmap_failed: + mutex_unlock(&proc_lock); + func_end: dev_dbg(bridge, "%s: hprocessor: 0x%p map_addr: 0x%p status: 0x%x\n", __func__, hprocessor, map_addr, status);