Linking glibc in fully static mode is mostly unsupported. While such binaries
can easily be produced, conflicting symbols will often make them crash at
runtime. This happens because glibc will always (try to) load some dynamically
linked libraries, even when statically linked. This includes things like the
resolver, unicode/locale handling and others.
Internally at Google, this is not a concern due to the way glibc is being built
there. But in order to make all of our tests run in the open-source version of
this code, we need to change strategy a bit.
As a rule of thumb, glibc can safely be linked statically if a program is
resonably simple and does not use any networking of locale dependent
facilities. Calling syscalls directly instead of the corresponding libc
wrappers works as well, of course.
This change adjusts linker flags and sandbox policies to be more compatible
with regular Linux distributions.
Tested:
- `ctest -R '[A-Z].*'` (all SAPI/Sandbox2 tests)
PiperOrigin-RevId: 429025901
Change-Id: I46b677d9eb61080a8fe868002a34a77de287bf2d
- Allow to specify multiple syscalls with `BlockSyscallsWithErrno()`
- Add functions to allow `unlink()` and `rename()` in all their spellings
PiperOrigin-RevId: 414987303
Change-Id: Ic0e680b785e8e3a3498f20e6a7403737e63fe876
This change should make it less confusing where utility code comes from.
Having it in two places made sense when we were debating whether to publish
Sandbox2 separately, but not any longer.
Follow-up changes will move `sandbox2/util.h` and rename the remaining
`sandbox2/util` folder.
PiperOrigin-RevId: 351601640
Change-Id: I6256845261f610e590c25e2c59851cc51da2d778
This is a work in progress:
- Syscall tables need work
- Only tested on real hardware using one of our test hosts
As a drive-by, this change also enables the open source version to function on
POWER.
Another side-effect of this change is that the default policies no longer
check for different host architectures at runtime. On x86_64, we do not need
to check for PPC or AArch64 specifice and vice versa.
PiperOrigin-RevId: 331137472
Change-Id: Ic6d6be5cbe61d83dbe13d5a0be036871754b2eb8
