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| author | Erik Bosman <ebn310@few.vu.nl> | 2008-04-11 18:54:17 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-19 19:19:55 +0200 |
| commit | 8fb402bccf203ecca8f9e0202b8fd3c937dece6f (patch) | |
| tree | 4f102f9cc81dedbf9271f728a4b1e6e731a6a174 | |
| parent | ftrace: add notrace annotations for NMI routines (diff) | |
| download | linux-8fb402bccf203ecca8f9e0202b8fd3c937dece6f.tar.xz linux-8fb402bccf203ecca8f9e0202b8fd3c937dece6f.zip | |
generic, x86: add prctl commands PR_GET_TSC and PR_SET_TSC
This patch adds prctl commands that make it possible
to deny the execution of timestamp counters in userspace.
If this is not implemented on a specific architecture,
prctl will return -EINVAL.
ned-off-by: Erik Bosman <ejbosman@cs.vu.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/prctl.h | 6 | ||||
| -rw-r--r-- | kernel/sys.c | 13 |
2 files changed, 18 insertions, 1 deletions
diff --git a/include/linux/prctl.h b/include/linux/prctl.h index 3800639775ae..5c80b1939636 100644 --- a/include/linux/prctl.h +++ b/include/linux/prctl.h @@ -67,4 +67,10 @@ #define PR_CAPBSET_READ 23 #define PR_CAPBSET_DROP 24 +/* Get/set the process' ability to use the timestamp counter instruction */ +#define PR_GET_TSC 25 +#define PR_SET_TSC 26 +# define PR_TSC_ENABLE 1 /* allow the use of the timestamp counter */ +# define PR_TSC_SIGSEGV 2 /* throw a SIGSEGV instead of reading the TSC */ + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sys.c b/kernel/sys.c index a626116af5db..6a0cc71ee88d 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -67,6 +67,12 @@ #ifndef SET_ENDIAN # define SET_ENDIAN(a,b) (-EINVAL) #endif +#ifndef GET_TSC_CTL +# define GET_TSC_CTL(a) (-EINVAL) +#endif +#ifndef SET_TSC_CTL +# define SET_TSC_CTL(a) (-EINVAL) +#endif /* * this is where the system-wide overflow UID and GID are defined, for @@ -1737,7 +1743,12 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, #else return -EINVAL; #endif - + case PR_GET_TSC: + error = GET_TSC_CTL(arg2); + break; + case PR_SET_TSC: + error = SET_TSC_CTL(arg2); + break; default: error = -EINVAL; break; |