This patch changes the return type of sys::Process::getPageSize to
Expected<unsigned> to account for the fact that the underlying syscalls used to
obtain the page size may fail (see below).
For clients who use the page size as an optimization only this patch adds a new
method, getPageSizeEstimate, which calls through to getPageSize but discards
any error returned and substitues a "reasonable" page size estimate estimate
instead. All existing LLVM clients are updated to call getPageSizeEstimate
rather than getPageSize.
On Unix, sys::Process::getPageSize is implemented in terms of getpagesize or
sysconf, depending on which macros are set. The sysconf call is documented to
return -1 on failure. On Darwin getpagesize is implemented in terms of sysconf
and may also fail (though the manpage documentation does not mention this).
These failures have been observed in practice when highly restrictive sandbox
permissions have been applied. Without this patch, the result is that
getPageSize returns -1, which wreaks havoc on any subsequent code that was
assuming a sane page size value.
<rdar://problem/41654857>
Reviewers: dblaikie, echristo
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59107
llvm-svn: 360221
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
MIPS `jr` instruction uses a delay-slot. To escape execution of
arbitrary instruction we should either fill the delay-slot by `nop`
instruction or swap `jr` instruction and logically preceding
instruction. This fix implements the second method to generate a bit
more effective code.
llvm-svn: 351001
MIPS ABI states that every function must be called through jalr $t9. In
other words, a function expect that t9 register points to the beginning
of its code. A function uses this register to calculate offset to the
Global Offset Table and save it to the `gp` register.
```
lui $gp, %hi(_gp_disp)
addiu $gp, %lo(_gp_disp)
addu $gp, $gp, $t9
```
If `t9` and as a result `$gp` point to the wrong place the following code
loads incorrect value from GOT and passes control to invalid code.
```
lw $v0,%call16(foo)($gp)
jalr $t9
```
OrcMips32 and OrcMips64 writeResolverCode methods pass control to the
resolved address, but do not setup `$t9` before the call. The `t9` holds
value of the beginning of `resolver` code so any attempts to call
routines via GOT failed.
This change fixes the problem. The `OrcLazy/hidden-visibility.ll` test
starts to pass correctly. Before the change it fails on MIPS because the
`exitOnLazyCallThroughFailure` called from the resolver code could not
call libc routine `exit` via GOT.
Differential Revision: http://reviews.llvm.org/D56058
llvm-svn: 351000
This patch adds support for ORC JIT for mips/mips64 architecture.
In common code $static is changed to __ORCstatic because on MIPS
architecture "$" is a reserved character.
Patch by Luka Ercegovcevic
Differential Revision: https://reviews.llvm.org/D49665
llvm-svn: 341934
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