* [PATCH] cpufrequtils aperf: Fix MSR read on 32-bit
@ 2010-12-08 16:39 Frank Arnold
2010-12-08 20:53 ` Thomas Renninger
2010-12-12 9:07 ` Dominik Brodowski
0 siblings, 2 replies; 3+ messages in thread
From: Frank Arnold @ 2010-12-08 16:39 UTC (permalink / raw)
To: Dominik Brodowski, Thomas Renninger; +Cc: Borislav Petkov, cpufreq
The cpufreq-aperf command does not work on 32-bit systems. The reason
for that is a wrong count argument passed to the read() call. Instead
of the buffer size, the size of the pointer to the buffer is used. On
64-bit systems this just happened to work, because we need to read an
8 byte value and a pointer has a size of 8 bytes on 64-bit. On 32-bit
systems only 4 bytes are read, which then triggers the error path.
Signed-off-by: Frank Arnold <frank.arnold@amd.com>
---
utils/aperf.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/utils/aperf.c b/utils/aperf.c
index 1c64501..6302f5a 100644
--- a/utils/aperf.c
+++ b/utils/aperf.c
@@ -100,7 +100,7 @@ static int read_msr(int cpu, unsigned int idx, unsigned long long *val)
return -1;
if (lseek(fd, idx, SEEK_CUR) == -1)
goto err;
- if (read(fd, val, sizeof val) != sizeof *val)
+ if (read(fd, val, sizeof *val) != sizeof *val)
goto err;
close(fd);
return 0;
--
1.7.2.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] cpufrequtils aperf: Fix MSR read on 32-bit
2010-12-08 16:39 [PATCH] cpufrequtils aperf: Fix MSR read on 32-bit Frank Arnold
@ 2010-12-08 20:53 ` Thomas Renninger
2010-12-12 9:07 ` Dominik Brodowski
1 sibling, 0 replies; 3+ messages in thread
From: Thomas Renninger @ 2010-12-08 20:53 UTC (permalink / raw)
To: Frank Arnold; +Cc: Dominik Brodowski, Borislav Petkov, cpufreq
On Wednesday 08 December 2010 17:39:14 Frank Arnold wrote:
> The cpufreq-aperf command does not work on 32-bit systems. The reason
> for that is a wrong count argument passed to the read() call. Instead
> of the buffer size, the size of the pointer to the buffer is used. On
> 64-bit systems this just happened to work, because we need to read an
> 8 byte value and a pointer has a size of 8 bytes on 64-bit. On 32-bit
> systems only 4 bytes are read, which then triggers the error path.
>
> Signed-off-by: Frank Arnold <frank.arnold@amd.com>
> ---
> utils/aperf.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/utils/aperf.c b/utils/aperf.c
> index 1c64501..6302f5a 100644
> --- a/utils/aperf.c
> +++ b/utils/aperf.c
> @@ -100,7 +100,7 @@ static int read_msr(int cpu, unsigned int idx,
unsigned long long *val)
> return -1;
> if (lseek(fd, idx, SEEK_CUR) == -1)
> goto err;
> - if (read(fd, val, sizeof val) != sizeof *val)
> + if (read(fd, val, sizeof *val) != sizeof *val)
Reviewed-by: trenn@suse.de
Thanks,
Thomas
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] cpufrequtils aperf: Fix MSR read on 32-bit
2010-12-08 16:39 [PATCH] cpufrequtils aperf: Fix MSR read on 32-bit Frank Arnold
2010-12-08 20:53 ` Thomas Renninger
@ 2010-12-12 9:07 ` Dominik Brodowski
1 sibling, 0 replies; 3+ messages in thread
From: Dominik Brodowski @ 2010-12-12 9:07 UTC (permalink / raw)
To: Frank Arnold; +Cc: Thomas Renninger, Borislav Petkov, cpufreq
Applied, thanks.
Best,
Dominik
^ permalink raw reply [flat|nested] 3+ messages in thread
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2010-12-08 16:39 [PATCH] cpufrequtils aperf: Fix MSR read on 32-bit Frank Arnold
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