Messages in this thread | | | Date | Wed, 9 Apr 2008 10:42:00 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 0/2] x86 vdso 32-bit vdso-disabling fixes |
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* Roland McGrath <roland@redhat.com> wrote:
> These two patches together address two potential bugs when trying to > disable the 32-bit vDSO via sysctl or boot parameters (vdso32=0). > > Currently, every 32-bit exec gets the vDSO mapped even if it's > disabled (the process just doesn't get told about it). Because it's > in fact always there, the bug that patch 1/2 fixes cannot happen now. > With patch 2/2, it won't be mapped at all when it's disabled, which is > one of the things that people might really want when they disable it > (so nothing they didn't ask for goes into their address space). > > The 32-bit signal handler setup when SA_RESTORER is not used refers to > current->mm->context.vdso without regard to whether the vDSO has been > disabled when the process was exec'd. Patch 1/2 fixes this not to use > it when it's null, which becomes possible after patch 2/2. (This > never happens in normal use, because glibc's sigaction call uses > SA_RESTORER unless glibc detected the vDSO.)
thanks Roland, applied.
Ingo
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