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* [S390] vdso: get rid of redefinition warningsHeiko Carstens2010-10-29
| | | | | | | | | | | | | | | | The CLOCK_* defines in asm-offsets.c are only used for the vdso code however in the meantime they cause other trouble. Just rename them to get permanently rid of this: In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0, from arch/s390/mm/fault.c:33: include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined include/linux/time.h:286:0: note: this is the location of the previous definition include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined include/linux/time.h:287:0: note: this is the location of the previous definition Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] vdso: use ntp adjusted clock multiplierHendrik Brueckner2010-04-22
| | | | | | | | | | | | | | | | | | Commit "timekeeping: Fix clock_gettime vsyscall time warp" (0696b711e) introduced the new parameter "mult" to update_vsyscall(). This parameter contains the internal NTP adjusted clock multiplier. The s390x vdso did not use this adjusted multiplier. Instead, it used the constant clock multiplier for gettimeofday() and clock_gettime() variants. This may result in observable time warps as explained in commit 0696b711e. Make the NTP adjusted clock multiplier available to the s390x vdso implementation and use it for time calculations. Cc: <stable@kernel.org> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] vdso: clock_gettime of CLOCK_THREAD_CPUTIME_ID with noexec=onMartin Schwidefsky2009-07-24
| | | | | | | | | | | | | | The combination of noexec=on and a clock_gettime call with clock id CLOCK_THREAD_CPUTIME_ID is broken. The vdso code switches to the access register mode to get access to the per-cpu data structure to execute the magic ectg instruction. After the ectg instruction the code always switches back to the primary mode but for noexec=on the correct mode is the secondary mode. The effect of the bug is that the user space program looses the access to all mappings without PROT_EXEC, e.g. the stack. The problem is fixed by restoring the mode that has been active before the switch to the access register mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_IDMartin Schwidefsky2008-12-31
| | | | | | | | | | | The extract cpu time instruction (ectg) instruction allows the user process to get the current thread cputime without calling into the kernel. The code that uses the instruction needs to switch to the access registers mode to get access to the per-cpu info page that contains the two base values that are needed to calculate the current cputime from the CPU timer with the ectg instruction. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] introduce vdso on s390Martin Schwidefsky2008-12-25
Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>