[PATCH 0/4] Add 32 bit VDSO time function support

2014-02-01 Thread stefani
From: Stefani Seibold This patch add the functions vdso_gettimeofday(), vdso_clock_gettime() and vdso_time() to the 32 bit VDSO. The reason to do this was to get a fast reliable time stamp. Many developers uses TSC to get a fast time stamp, without knowing the pitfalls. VDSO time functions a fas

Re: [PATCH 0/4] Add 32 bit VDSO time function support

2014-01-30 Thread Andy Lutomirski
On Thu, Jan 30, 2014 at 10:03 AM, H. Peter Anvin wrote: > On 01/30/2014 09:57 AM, Andy Lutomirski wrote: >> >> By definition there aren't any broken users of the new functions, >> because there aren't any users at all. So... should we start >> randomizing this thing from the beginning? >> > > The

Re: [PATCH 0/4] Add 32 bit VDSO time function support

2014-01-30 Thread H. Peter Anvin
On 01/30/2014 09:57 AM, Andy Lutomirski wrote: > > By definition there aren't any broken users of the new functions, > because there aren't any users at all. So... should we start > randomizing this thing from the beginning? > The vdso already exists. It isn't new. Randomizing it might be a g

Re: [PATCH 0/4] Add 32 bit VDSO time function support

2014-01-30 Thread Andy Lutomirski
On Thu, Jan 30, 2014 at 7:52 AM, Stefani Seibold wrote: > Am Donnerstag, den 30.01.2014, 07:31 -0800 schrieb H. Peter Anvin: >> On 01/30/2014 02:49 AM, stef...@seibold.net wrote: >> > The VDSO page for a 32 bit resided now on 0xc000, followed by the VVAR >> > and >> > HPET page. >> >> Any rea

Re: [PATCH 0/4] Add 32 bit VDSO time function support

2014-01-30 Thread H. Peter Anvin
On 01/30/2014 07:52 AM, Stefani Seibold wrote: > > The reason is that i get need than an additional VMA for HPET and VVAR. > > I seen no break of applications since the __FIXADDR_TOP is not on a fix > place. Lguest, XEN, OPLC and the reservetop Kernel Parameter will change > the VDSO Page Addres

Re: [PATCH 0/4] Add 32 bit VDSO time function support

2014-01-30 Thread Stefani Seibold
Am Donnerstag, den 30.01.2014, 07:31 -0800 schrieb H. Peter Anvin: > On 01/30/2014 02:49 AM, stef...@seibold.net wrote: > > The VDSO page for a 32 bit resided now on 0xc000, followed by the VVAR > > and > > HPET page. > > Any reason to not move the vdso base page to the top, in order to avoid

Re: [PATCH 0/4] Add 32 bit VDSO time function support

2014-01-30 Thread H. Peter Anvin
On 01/30/2014 02:49 AM, stef...@seibold.net wrote: > The VDSO page for a 32 bit resided now on 0xc000, followed by the VVAR and > HPET page. Any reason to not move the vdso base page to the top, in order to avoid breaking broken applications? It seems a fairly innocuous shuffle... probably li

[PATCH 0/4] Add 32 bit VDSO time function support

2014-01-30 Thread stefani
From: Stefani Seibold This patch add the functions vdso_gettimeofday(), vdso_clock_gettime() and vdso_time() to the 32 bit VDSO. The reason to do this was to get a fast reliable time stamp. Many developers uses TSC to get a fast time stamp, without knowing the pitfalls. VDSO time functions a fas