On Tue, Dec 4, 2018 at 1:26 PM Sean Christopherson <sean.j.christopher...@intel.com> wrote: > > At one point the vDSO image was manually stripped down by vdso2c in an > attempt to minimize the size of the image mapped into userspace. Part > of that stripping process involved building a fake section table so as > not to break userspace processes that parse the section table. Memory > for the fake section table was reserved in the .rodata section so that > vdso2c could simply copy the entire PT_LOAD segment into the userspace > image after building the fake table. > > Eventually, the entire fake section table approach was dropped in favor > of stripping the vdso "the old fashioned way", i.e. via objdump -S. > But, the reservation in .rodata for the fake table was left behind. > Remove the reserveration along with a few other related defines and > section entries. > > Removing the fake section table placeholder zaps a whopping 0x340 bytes > from the 64-bit vDSO image, which drops the current image's size to > under 4k, i.e. reduces the effective size of the userspace vDSO mapping > by a full page.
Acked-by: Andy Lutomirski <l...@kernel.org>
