Messages in this thread Patch in this message | | | From | Joerg Roedel <> | Subject | [PATCH] swiotlb: Return error from swiotlb_init_with_tbl() | Date | Thu, 31 Jan 2019 17:24:24 +0100 |
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From: Joerg Roedel <jroedel@suse.de>
The only reason why swiotlb_init_with_tbl() can fail is an allocation failure in the memblock_alloc() function. But this function just calls panic() in case it can't fulfill the request and never returns an error, therefore swiotlb_init_with_tbl() also never actually returns an error.
There are three call-sites of this function in the kernel. All of them check for an error being returned, and two of them call panic() itself in case the function returns an error. The third call-site handles the error case and doesn't crash the system. This is in the swiotlb_init() function.
Since there is a call-site which handles an error and does not crash the system, change the function to return allocation failures to the caller.
Signed-off-by: Joerg Roedel <jroedel@suse.de> --- kernel/dma/swiotlb.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index c873f9cc2146..4619d078c67c 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -203,12 +203,15 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE * between io_tlb_start and io_tlb_end. */ - io_tlb_list = memblock_alloc( + io_tlb_list = memblock_alloc_nopanic( PAGE_ALIGN(io_tlb_nslabs * sizeof(int)), PAGE_SIZE); - io_tlb_orig_addr = memblock_alloc( + io_tlb_orig_addr = memblock_alloc_nopanic( PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)), PAGE_SIZE); + if (io_tlb_list == NULL || io_tlb_orig_addr == NULL) + goto out_fail; + for (i = 0; i < io_tlb_nslabs; i++) { io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE); io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; @@ -219,7 +222,26 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) swiotlb_print_info(); swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT); + return 0; + +out_fail: + if (io_tlb_list) + memblock_free(io_tlb_list, + PAGE_ALIGN(io_tlb_nslabs * sizeof(int))); + + if (io_tlb_orig_addr) + memblock_free(io_tlb_orig_addr, + PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t))); + + io_tlb_list = NULL; + io_tlb_orig_addr = NULL; + io_tlb_end = 0; + io_tlb_start = 0; + io_tlb_nslabs = 0; + max_segment = 0; + + return -ENOMEM; } /* -- 2.16.4
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