From 970655aa9b42461f8394e4457307005bdeee14d9 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 23 Apr 2021 07:40:38 +0200 Subject: xen/gntdev: fix gntdev_mmap() error exit path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit d3eeb1d77c5d0af ("xen/gntdev: use mmu_interval_notifier_insert") introduced an error in gntdev_mmap(): in case the call of mmu_interval_notifier_insert_locked() fails the exit path should not call mmu_interval_notifier_remove(), as this might result in NULL dereferences. One reason for failure is e.g. a signal pending for the running process. Fixes: d3eeb1d77c5d0af ("xen/gntdev: use mmu_interval_notifier_insert") Cc: stable@vger.kernel.org Reported-by: Marek Marczykowski-Górecki Tested-by: Marek Marczykowski-Górecki Signed-off-by: Juergen Gross Reviewed-by: Luca Fancellu Link: https://lore.kernel.org/r/20210423054038.26696-1-jgross@suse.com Signed-off-by: Juergen Gross --- drivers/xen/gntdev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index f01d58c7a042..a3e7be96527d 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1017,8 +1017,10 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) err = mmu_interval_notifier_insert_locked( &map->notifier, vma->vm_mm, vma->vm_start, vma->vm_end - vma->vm_start, &gntdev_mmu_ops); - if (err) + if (err) { + map->vma = NULL; goto out_unlock_put; + } } mutex_unlock(&priv->lock); -- cgit v1.2.3 From dbc03e81586fc33e4945263fd6e09e22eb4b980f Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Sat, 8 May 2021 10:19:13 +0800 Subject: xen/unpopulated-alloc: fix error return code in fill_list() Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: a4574f63edc6 ("mm/memremap_pages: convert to 'struct range'") Reported-by: Hulk Robot Signed-off-by: Zhen Lei Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20210508021913.1727-1-thunder.leizhen@huawei.com Signed-off-by: Juergen Gross --- drivers/xen/unpopulated-alloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/unpopulated-alloc.c b/drivers/xen/unpopulated-alloc.c index e64e6befc63b..87e6b7db892f 100644 --- a/drivers/xen/unpopulated-alloc.c +++ b/drivers/xen/unpopulated-alloc.c @@ -39,8 +39,10 @@ static int fill_list(unsigned int nr_pages) } pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL); - if (!pgmap) + if (!pgmap) { + ret = -ENOMEM; goto err_pgmap; + } pgmap->type = MEMORY_DEVICE_GENERIC; pgmap->range = (struct range) { -- cgit v1.2.3 From cb6f6b3384d7825d2a43f2256c5200e3b3956fc8 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 12 May 2021 13:18:21 -0700 Subject: xen/arm: move xen_swiotlb_detect to arm/swiotlb-xen.h Move xen_swiotlb_detect to a static inline function to make it available to !CONFIG_XEN builds. CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Stefano Stabellini Reviewed-by: Christoph Hellwig Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20210512201823.1963-1-sstabellini@kernel.org Signed-off-by: Juergen Gross --- arch/arm/xen/mm.c | 12 ------------ include/xen/arm/swiotlb-xen.h | 15 ++++++++++++++- 2 files changed, 14 insertions(+), 13 deletions(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index f8f07469d259..223b1151fd7d 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -135,18 +135,6 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) return; } -int xen_swiotlb_detect(void) -{ - if (!xen_domain()) - return 0; - if (xen_feature(XENFEAT_direct_mapped)) - return 1; - /* legacy case */ - if (!xen_feature(XENFEAT_not_direct_mapped) && xen_initial_domain()) - return 1; - return 0; -} - static int __init xen_mm_init(void) { struct gnttab_cache_flush cflush; diff --git a/include/xen/arm/swiotlb-xen.h b/include/xen/arm/swiotlb-xen.h index 2994fe6031a0..33336ab58afc 100644 --- a/include/xen/arm/swiotlb-xen.h +++ b/include/xen/arm/swiotlb-xen.h @@ -2,6 +2,19 @@ #ifndef _ASM_ARM_SWIOTLB_XEN_H #define _ASM_ARM_SWIOTLB_XEN_H -extern int xen_swiotlb_detect(void); +#include +#include + +static inline int xen_swiotlb_detect(void) +{ + if (!xen_domain()) + return 0; + if (xen_feature(XENFEAT_direct_mapped)) + return 1; + /* legacy case */ + if (!xen_feature(XENFEAT_not_direct_mapped) && xen_initial_domain()) + return 1; + return 0; +} #endif /* _ASM_ARM_SWIOTLB_XEN_H */ -- cgit v1.2.3 From 687842ec50342b716953f5847a49dd337cb6de8c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 12 May 2021 13:18:22 -0700 Subject: arm64: do not set SWIOTLB_NO_FORCE when swiotlb is required Although SWIOTLB_NO_FORCE is meant to allow later calls to swiotlb_init, today dma_direct_map_page returns error if SWIOTLB_NO_FORCE. For now, without a larger overhaul of SWIOTLB_NO_FORCE, the best we can do is to avoid setting SWIOTLB_NO_FORCE in mem_init when we know that it is going to be required later (e.g. Xen requires it). CC: boris.ostrovsky@oracle.com CC: jgross@suse.com CC: catalin.marinas@arm.com CC: will@kernel.org CC: linux-arm-kernel@lists.infradead.org Fixes: 2726bf3ff252 ("swiotlb: Make SWIOTLB_NO_FORCE perform no allocation") Signed-off-by: Christoph Hellwig Signed-off-by: Stefano Stabellini Reviewed-by: Juergen Gross Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20210512201823.1963-2-sstabellini@kernel.org Signed-off-by: Juergen Gross --- arch/arm64/mm/init.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 16a2b2b1c54d..e55409caaee3 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -43,6 +43,7 @@ #include #include #include +#include /* * We need to be able to catch inadvertent references to memstart_addr @@ -482,7 +483,7 @@ void __init mem_init(void) if (swiotlb_force == SWIOTLB_FORCE || max_pfn > PFN_DOWN(arm64_dma_phys_limit)) swiotlb_init(1); - else + else if (!xen_swiotlb_detect()) swiotlb_force = SWIOTLB_NO_FORCE; set_max_mapnr(max_pfn - PHYS_PFN_OFFSET); -- cgit v1.2.3 From 97729b653de52ba98e08732dd8855586e37a3a31 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 12 May 2021 13:18:23 -0700 Subject: xen/swiotlb: check if the swiotlb has already been initialized xen_swiotlb_init calls swiotlb_late_init_with_tbl, which fails with -ENOMEM if the swiotlb has already been initialized. Add an explicit check io_tlb_default_mem != NULL at the beginning of xen_swiotlb_init. If the swiotlb is already initialized print a warning and return -EEXIST. On x86, the error propagates. On ARM, we don't actually need a special swiotlb buffer (yet), any buffer would do. So ignore the error and continue. CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210512201823.1963-3-sstabellini@kernel.org Signed-off-by: Juergen Gross --- arch/arm/xen/mm.c | 8 +++++++- drivers/xen/swiotlb-xen.c | 5 +++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 223b1151fd7d..a7e54a087b80 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -138,9 +138,15 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) static int __init xen_mm_init(void) { struct gnttab_cache_flush cflush; + int rc; + if (!xen_swiotlb_detect()) return 0; - xen_swiotlb_init(); + + rc = xen_swiotlb_init(); + /* we can work with the default swiotlb */ + if (rc < 0 && rc != -EEXIST) + return rc; cflush.op = 0; cflush.a.dev_bus_addr = 0; diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 4c89afc0df62..24d11861ac7d 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -164,6 +164,11 @@ int __ref xen_swiotlb_init(void) int rc = -ENOMEM; char *start; + if (io_tlb_default_mem != NULL) { + pr_warn("swiotlb buffer already initialized\n"); + return -EEXIST; + } + retry: m_ret = XEN_SWIOTLB_ENOMEM; order = get_order(bytes); -- cgit v1.2.3