This is in preparation for my next change, which will introduce a relro
nobits section. That requires that relro sections appear at the end of the
progbits part of the r/w segment so that the relro nobits section can appear
contiguously.
Because of the amount of churn required in the test suite, I'm making this
change separately.
llvm-svn: 291523
The MipsGotSection::getPageEntryOffset calculates index of GOT entry
with a "page" address. Previously this method changes the state
of MipsGotSection because it modifies PageIndexMap field. That leads
to the unpredictable results if getPageEntryOffset called from multiple threads.
The patch makes getPageEntryOffset constant. To do so it calculates GOT
entry index but does not update PageIndexMap field. Later in the
MipsGotSection::writeTo method linker calculates "page" addresses and
writes them to the output.
llvm-svn: 288129
If output section which referenced by R_MIPS_GOT_PAGE or R_MIPS_GOT16
relocations is small (less that 0x10000 bytes) and occupies two adjacent
0xffff-bytes pages, current formula gives incorrect number of required "page"
GOT entries. The problem is that in time of calculation we do not know
the section address and so we cannot calculate number of 0xffff-bytes
pages exactly.
This patch fix the formula. Now it gives a correct number of pages in
the worst case when "small" section intersects 0xffff-bytes page
boundary. From the other side, sometimes it adds one more redundant GOT
entry for each output section. But usually number of output sections
referenced by GOT relocations is small.
llvm-svn: 288127
Local symbol which requires GOT entry initialized by "page" address.
This address is high 16 bits of sum of the symbol value and the relocation
addend. In the relocation scanning phase final values of symbols are unknown
so to reduce number of allocated GOT entries do the following trick. Save
all output sections referenced by GOT relocations during the relocation
scanning phase. Then later in the `GotSection::finalize` method calculate
number of "pages" required to cover all saved output sections and allocate
appropriate number of GOT entries. We assume the worst case - each 64kb
page of the output section has at least one GOT relocation against it.
Differential Revision: http://reviews.llvm.org/D18349
llvm-svn: 264730
Simon Atanasyan