Re: [PATCH v1] perf cap: Add __NR_capget to arch/x86 unistd

From: Adrian Hunter
Date: Mon Oct 28 2024 - 03:25:59 EST


On 26/10/24 09:00, Ian Rogers wrote:
> On Fri, Oct 25, 2024 at 10:54 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>>
>> As there are duplicated kernel headers in tools/include libc can pick
>> up the wrong definitions. This was causing the wrong system call for
>> capget in perf.
>>
>> Closes: https://lore.kernel.org/lkml/cc7d6bdf-1aeb-4179-9029-4baf50b59342@xxxxxxxxx/
>> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
>
> Forgot:
> Fixes: e25ebda78e23 ("perf cap: Tidy up and improve capability testing")

Works for me, thank you!

Tested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

>
> Thanks,
> Ian
>
>> ---
>> tools/arch/x86/include/uapi/asm/unistd_32.h | 3 +++
>> tools/arch/x86/include/uapi/asm/unistd_64.h | 3 +++
>> tools/perf/util/cap.c | 10 +++-------
>> 3 files changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/tools/arch/x86/include/uapi/asm/unistd_32.h b/tools/arch/x86/include/uapi/asm/unistd_32.h
>> index 9de35df1afc3..63182a023e9d 100644
>> --- a/tools/arch/x86/include/uapi/asm/unistd_32.h
>> +++ b/tools/arch/x86/include/uapi/asm/unistd_32.h
>> @@ -11,6 +11,9 @@
>> #ifndef __NR_getpgid
>> #define __NR_getpgid 132
>> #endif
>> +#ifndef __NR_capget
>> +#define __NR_capget 184
>> +#endif
>> #ifndef __NR_gettid
>> #define __NR_gettid 224
>> #endif
>> diff --git a/tools/arch/x86/include/uapi/asm/unistd_64.h b/tools/arch/x86/include/uapi/asm/unistd_64.h
>> index d0f2043d7132..77311e8d1b5d 100644
>> --- a/tools/arch/x86/include/uapi/asm/unistd_64.h
>> +++ b/tools/arch/x86/include/uapi/asm/unistd_64.h
>> @@ -11,6 +11,9 @@
>> #ifndef __NR_getpgid
>> #define __NR_getpgid 121
>> #endif
>> +#ifndef __NR_capget
>> +#define __NR_capget 125
>> +#endif
>> #ifndef __NR_gettid
>> #define __NR_gettid 186
>> #endif
>> diff --git a/tools/perf/util/cap.c b/tools/perf/util/cap.c
>> index 7574a67651bc..69d9a2bcd40b 100644
>> --- a/tools/perf/util/cap.c
>> +++ b/tools/perf/util/cap.c
>> @@ -7,13 +7,9 @@
>> #include "debug.h"
>> #include <errno.h>
>> #include <string.h>
>> -#include <unistd.h>
>> #include <linux/capability.h>
>> #include <sys/syscall.h>
>> -
>> -#ifndef SYS_capget
>> -#define SYS_capget 90
>> -#endif
>> +#include <unistd.h>
>>
>> #define MAX_LINUX_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3
>>
>> @@ -21,9 +17,9 @@ bool perf_cap__capable(int cap, bool *used_root)
>> {
>> struct __user_cap_header_struct header = {
>> .version = _LINUX_CAPABILITY_VERSION_3,
>> - .pid = getpid(),
>> + .pid = 0,
>> };
>> - struct __user_cap_data_struct data[MAX_LINUX_CAPABILITY_U32S];
>> + struct __user_cap_data_struct data[MAX_LINUX_CAPABILITY_U32S] = {};
>> __u32 cap_val;
>>
>> *used_root = false;
>> --
>> 2.47.0.163.g1226f6d8fa-goog
>>