From: David Ahern <dsahern@gmail.com>
To: Stephane Eranian <eranian@google.com>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
acme@redhat.com, mingo@elte.hu
Subject: Re: [PATCH] perf: fix perf.data endianness detection
Date: Tue, 20 Sep 2011 13:23:16 -0600 [thread overview]
Message-ID: <4E78E824.4080209@gmail.com> (raw)
In-Reply-To: <CABPqkBRDhKUZf0FvShGbQWoPPAWAHA+XbUUqxDY+M1J9_gDiuQ@mail.gmail.com>
On 09/20/2011 01:02 PM, Stephane Eranian wrote:
>>> +static int check_magic_endian(u64 *magic, struct perf_file_header *header,
>>> + struct perf_header *ph)
>>> +{
>>> + int ret;
>>> +
>>> + /* check for legacy format */
>>> + ret = memcmp(magic, __perf_magic1, sizeof(*magic));
>>> + if (ret == 0) {
>>> + pr_debug("legacy perf.data format\n");
>>> + if (!header)
>>> + return -1;
>>> +
>>> + if (header->attr_size != sizeof(struct perf_file_attr)) {
>>> + u64 attr_size = bswap_64(header->attr_size);
>>> +
>>> + if (attr_size != sizeof(struct perf_file_attr))
>>> + return -1;
>>> +
>>> + mem_bswap_64(header, offsetof(struct perf_file_header,
>>> + adds_features));
>>> + ph->needs_swap = true;
>>> + }
>>> + return 0;
>>> + }
>>> +
>>> + /* check for our magic (same endianness) */
>>> + if (*magic == __perf_magic2)
>>> + return 0;
>>> +
>>> + /* check for our magic (opposite endianness) */
>>> + if (*magic != __perf_magic2_sw)
>>> + return -1;
>>> +
>>> + ph->needs_swap = true;
--> goes here too
|
|
>>> +
>>> + return 0;
>>> +}
>>> +
>>> int perf_file_header__read(struct perf_file_header *header,
>>> struct perf_header *ph, int fd)
>>> {
>>> + int ret;
>>> +
>>> lseek(fd, 0, SEEK_SET);
>>>
>>> - if (readn(fd, header, sizeof(*header)) <= 0 ||
>>> - memcmp(&header->magic, __perf_magic, sizeof(header->magic)))
>>> + ret = readn(fd, header, sizeof(*header));
>>> + if (ret <= 0)
>>> return -1;
>>>
>>> - if (header->attr_size != sizeof(struct perf_file_attr)) {
>>> - u64 attr_size = bswap_64(header->attr_size);
>>> -
>>> - if (attr_size != sizeof(struct perf_file_attr))
>>> - return -1;
>>> -
>>> - mem_bswap_64(header, offsetof(struct perf_file_header,
>>> - adds_features));
|
|---- the mem_bswap_64()
prev parent reply other threads:[~2011-09-20 19:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-19 9:56 [PATCH] perf: fix perf.data endianness detection Stephane Eranian
2011-09-20 18:59 ` David Ahern
2011-09-20 19:02 ` Stephane Eranian
2011-09-20 19:23 ` David Ahern [this message]
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