matches static binaries.
Interpretation of the 'static' there is that the binary must not
specify an interpreter. In particular, shared objects are matched by
the brand if BI_CAN_EXEC_DYN is also set.
This improves precision of the brand matching, which should eliminate
surprises due to brand ordering.
Revert r315701.
Discussed with and tested by: ed (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
CloudABI executables are statically linked and don't have an
interpreter. Setting the interpreter path to NULL used to work
previously, but r314851 introduced code that checks the string
unconditionally. Running CloudABI executables now causes a null pointer
dereference.
Looking at the rest of imgact_elf.c, it seems various other codepaths
already leaned on the fact that the interpreter path is set. Let's just
go ahead and pick an obviously incorrect interpreter path to appease
imgact_elf.c.
MFC after: 1 week
A nice thing about requiring a vDSO is that it makes it incredibly easy
to provide full support for running 32-bit processes on 64-bit systems.
Instead of letting the kernel be responsible for composing/decomposing
64-bit arguments across multiple registers/stack slots, all of this can
now be done in the vDSO. This means that there is no need to provide
duplicate copies of certain system calls, like the sys_lseek() and
freebsd32_lseek() we have for COMPAT_FREEBSD32.
This change imports a new vDSO from the CloudABI repository that has
automatically generated code in it that copies system call arguments
into a buffer, padding them to eight bytes and zero-extending any
pointers/size_t arguments. After returning from the kernel, it does the
inverse: extracting return values, in the process truncating
pointers/size_t values to 32 bits.
Obtained from: https://github.com/NuxiNL/cloudabi
