Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1180311

Re: [RESEND 2][PATCH v4] hexdump: fix for non-aligned buffers

From Joe Perches <joe@perches.com>
Newsgroups linux.kernel
Subject Re: [RESEND 2][PATCH v4] hexdump: fix for non-aligned buffers
Date 2015-07-09 01:50 +0200
Message-ID <pK7ge-183-17@gated-at.bofh.it> (permalink)
References <pK7ge-183-13@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Thu, 2015-07-09 at 01:44 +0200, Horacio Mijail Antón Quiles wrote:
> An hexdump with a buf not aligned to the groupsize causes
> non-naturally-aligned memory accesses. This was causing a kernel panic on
> the processor BlackFin BF527, when such an unaligned buffer was fed by the
> function ubifs_scanned_corruption in fs/ubifs/scan.c .

Seems sensible enough to me.

> ---
> diff --git a/lib/hexdump.c b/lib/hexdump.c
[]
> @@ -124,6 +124,11 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
>  	if ((len % groupsize) != 0)	/* no mixed size output */
>  		groupsize = 1;
>  
> +	/* fall back to 1-byte groups if buf is not aligned to groupsize */
> +	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
> +	    !IS_ALIGNED((uintptr_t)buf, groupsize))
> +		groupsize = 1;
> +
>  	ngroups = len / groupsize;
>  	ascii_column = rowsize * 2 + rowsize / groupsize + 1;
>  


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[RESEND 2][PATCH v4] hexdump: fix for non-aligned buffers Horacio Mijail Antón Quiles <hmijail@gmail.com> - 2015-07-09 01:50 +0200
  Re: [RESEND 2][PATCH v4] hexdump: fix for non-aligned buffers Joe Perches <joe@perches.com> - 2015-07-09 01:50 +0200
  Re: [RESEND 2][PATCH v4] hexdump: fix for non-aligned buffers Andrew Morton <akpm@linux-foundation.org> - 2015-07-09 02:10 +0200
    Re: [RESEND 2][PATCH v4] hexdump: fix for non-aligned buffers Geert Uytterhoeven <geert@linux-m68k.org> - 2015-07-09 09:20 +0200

csiph-web