From: Petr Mladek <pmladek@suse.com>
To: Alastair D'Silva <alastair@au1.ibm.com>
Cc: alastair@d-silva.org, Jani Nikula <jani.nikula@linux.intel.com>,
Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Karsten Keil <isdn@linux-pingi.de>,
Jassi Brar <jassisinghbrar@gmail.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
"David S. Miller" <davem@davemloft.net>,
Jose Abreu <Jose.Abreu@synopsys.com>,
Kalle Valo <kvalo@codeaurora.org>,
Stanislaw Gruszka <sgruszka@redhat.com>,
Benson Leung <bleung@chromium.org>,
Enric Balletbo i Serra <enric.balletbo@collabora.com>,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Andrew Morton <akpm@linux-foundation.org>,
intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
ath10k@lists.infradead.org, linux-wireless@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org,
devel@driverdev.osuosl.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 2/4] lib/hexdump.c: Optionally suppress lines of filler bytes
Date: Fri, 12 Apr 2019 16:03:53 +0200 [thread overview]
Message-ID: <20190412140353.mgvksn3yk6n65hbk@pathway.suse.cz> (raw)
In-Reply-To: <20190410031720.11067-3-alastair@au1.ibm.com>
On Wed 2019-04-10 13:17:18, Alastair D'Silva wrote:
> From: Alastair D'Silva <alastair@d-silva.org>
>
> Some buffers may only be partially filled with useful data, while the rest
> is padded (typically with 0x00 or 0xff).
>
> This patch introduces flags which allow lines of padding bytes to be
> suppressed, making the output easier to interpret: HEXDUMP_SUPPRESS_0X00,
> HEXDUMP_SUPPRESS_0XFF
>
> The first and last lines are not suppressed by default, so the function
> always outputs something. This behaviour can be further controlled with
> the HEXDUMP_SUPPRESS_FIRST & HEXDUMP_SUPPRESS_LAST flags.
>
> An inline wrapper function is provided for backwards compatibility with
> existing code, which maintains the original behaviour.
>
> diff --git a/lib/hexdump.c b/lib/hexdump.c
> index b8a164814744..2f3bafb55a44 100644
> --- a/lib/hexdump.c
> +++ b/lib/hexdump.c
> +void print_hex_dump_ext(const char *level, const char *prefix_str,
> + int prefix_type, int rowsize, int groupsize,
> + const void *buf, size_t len, u64 flags)
> {
> const u8 *ptr = buf;
> - int i, linelen, remaining = len;
> + int i, remaining = len;
> unsigned char linebuf[64 * 3 + 2 + 64 + 1];
> + bool first_line = true;
>
> if (rowsize != 16 && rowsize != 32 && rowsize != 64)
> rowsize = 16;
>
> for (i = 0; i < len; i += rowsize) {
> - linelen = min(remaining, rowsize);
> + bool skip = false;
> + int linelen = min(remaining, rowsize);
> +
> remaining -= rowsize;
>
> + if (flags & HEXDUMP_SUPPRESS_0X00)
> + skip = buf_is_all(ptr + i, linelen, 0x00);
> +
> + if (!skip && (flags & HEXDUMP_SUPPRESS_0XFF))
> + skip = buf_is_all(ptr + i, linelen, 0xff);
> +
> + if (first_line && !(flags & HEXDUMP_SUPPRESS_FIRST))
> + skip = false;
> +
> + if (remaining <= 0 && !(flags & HEXDUMP_SUPPRESS_LAST))
> + skip = false;
> +
> + if (skip)
> + continue;
IMHO, quietly skipping lines could cause a lot of confusion,
espcially when the address is not printed.
I wonder how it would look like when we print something like:
--- skipped XX lines full of 0x00 ---
Then we might even remove the SUPPRESS_FIRST, SUPPRESS_LAST
and the ambiguous QUIET flags.
> +
> + first_line = false;
This should be above the if (skip).
> +
> hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
> - linebuf, sizeof(linebuf), ascii);
> + linebuf, sizeof(linebuf),
> + flags & HEXDUMP_ASCII);
>
> switch (prefix_type) {
> case DUMP_PREFIX_ADDRESS:
> @@ -272,7 +316,7 @@ void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
> }
> }
> }
> -EXPORT_SYMBOL(print_hex_dump);
> +EXPORT_SYMBOL(print_hex_dump_ext);
We should still export even the original function that
is still used everywhere.
Best Regards,
Petr
next prev parent reply other threads:[~2019-04-12 14:04 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-10 3:17 [PATCH 0/4] Hexdump enhancements Alastair D'Silva
2019-04-10 3:17 ` [PATCH 1/4] lib/hexdump.c: Allow 64 bytes per line Alastair D'Silva
2019-04-12 13:48 ` Petr Mladek
2019-04-12 23:22 ` Alastair D'Silva
2019-04-15 9:02 ` Petr Mladek
2019-04-15 10:29 ` Alastair D'Silva
2019-04-15 10:56 ` David Laight
2019-04-15 10:59 ` Alastair D'Silva
2019-04-10 3:17 ` [PATCH 2/4] lib/hexdump.c: Optionally suppress lines of filler bytes Alastair D'Silva
2019-04-10 3:32 ` Alastair D'Silva
2019-04-12 14:03 ` Petr Mladek [this message]
2019-04-12 23:28 ` Alastair D'Silva
2019-04-15 9:18 ` Petr Mladek
2019-04-15 10:33 ` Alastair D'Silva
2019-04-10 3:17 ` [PATCH 3/4] lib/hexdump.c: Replace ascii bool in hex_dump_to_buffer with flags Alastair D'Silva
2019-04-10 6:56 ` Dan Carpenter
2019-04-12 14:12 ` Petr Mladek
2019-04-12 23:31 ` Alastair D'Silva
2019-04-15 9:24 ` Petr Mladek
2019-04-15 10:07 ` Alastair D'Silva
2019-04-15 10:20 ` David Laight
2019-04-15 10:44 ` Alastair D'Silva
2019-04-15 11:03 ` David Laight
2019-04-15 11:12 ` Alastair D'Silva
2019-04-12 14:47 ` [Intel-gfx] " Tvrtko Ursulin
2019-04-10 3:17 ` [PATCH 4/4] lib/hexdump.c: Allow multiple groups to be separated by lines '|' Alastair D'Silva
2019-04-10 8:45 ` David Laight
2019-04-10 9:52 ` Alastair D'Silva
2019-04-10 8:53 ` Sergey Senozhatsky
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