Re: [PATCH AUTOSEL 5.0 008/262] swiotlb: add checks for the return value of memblock_alloc*()

Mike Rapoport
2019-03-28T05:55:41Z

Hi,

On Wed, Mar 27, 2019 at 01:57:43PM -0400, Sasha Levin wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> [ Upstream commit a0bf842e89a3842162aa8514b9bf4611c86fee10 ]
>
> Add panic() calls if memblock_alloc() returns NULL.
>
> The panic() format duplicates the one used by memblock itself and in
> order to avoid explosion with long parameters list replace open coded
> allocation size calculations with a local variable.

This patch is a part of a series that removes panic() calls from memblock
allocators rather than a fix.

> Link: http://lkml.kernel.org/r/1548057848-15136-19-git-send-email-rppt@linux.ibm.com
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Christophe Leroy <christophe.leroy@c-s.fr>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Dennis Zhou <dennis@kernel.org>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Greentime Hu <green.hu@gmail.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Guan Xuetao <gxt@pku.edu.cn>
> Cc: Guo Ren <guoren@kernel.org>
> Cc: Guo Ren <ren_guo@c-sky.com> [c-sky]
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Juergen Gross <jgross@suse.com> [Xen]
> Cc: Mark Salter <msalter@redhat.com>
> Cc: Matt Turner <mattst88@gmail.com>
> Cc: Max Filippov <jcmvbkbc@gmail.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Michal Simek <monstr@monstr.eu>
> Cc: Paul Burton <paul.burton@mips.com>
> Cc: Petr Mladek <pmladek@suse.com>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Rich Felker <dalias@libc.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Stafford Horne <shorne@gmail.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Vineet Gupta <vgupta@synopsys.com>
> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> kernel/dma/swiotlb.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index c873f9cc2146..41224f0ec40e 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -191,6 +191,7 @@ void __init swiotlb_update_mem_attributes(void)
> int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> {
> unsigned long i, bytes;
> + size_t alloc_size;
>
> bytes = nslabs << IO_TLB_SHIFT;
>
> @@ -203,12 +204,18 @@ 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(
> - PAGE_ALIGN(io_tlb_nslabs * sizeof(int)),
> - PAGE_SIZE);
> - io_tlb_orig_addr = memblock_alloc(
> - PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)),
> - PAGE_SIZE);
> + alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(int));
> + io_tlb_list = memblock_alloc(alloc_size, PAGE_SIZE);
> + if (!io_tlb_list)
> + panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
> + __func__, alloc_size, PAGE_SIZE);
> +
> + alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t));
> + io_tlb_orig_addr = memblock_alloc(alloc_size, PAGE_SIZE);
> + if (!io_tlb_orig_addr)
> + panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
> + __func__, alloc_size, PAGE_SIZE);
> +
> 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;
> --
> 2.19.1
>

--
Sincerely yours,
Mike.