Apologies for the enormous commit, but I don't see a way to split this
up nicely. In the vast majority of cases it's a simple change. A few
extra places can use TRY instead of manual error checking though. :^)
Previously, Emulator::virt$execve would not report ENOENT and EACCES
when the binary to be executed was nonexistent or not executable. This
broke the execp family of functions, which rely on ENOENT being reported
in order to know that they should continue searching $PATH.
Emulator::virt$execve would construct command lines such as
`/bin/UserspaceEmulator echo -- hello` instead of
`/bin/UserspaceEmulator -- echo hello`, which naturally caused problems.
This commit moves the "--" to the correct place.
This function is an extended version of `chmod(2)` that lets one control
whether to dereference symlinks, and specify a file descriptor to a
directory that will be used as the base for relative paths.
This commit fixes an issue where zero-alignment would lead to the
requested range being allocated outside of the total available range,
hitting an assert in RangeAllocator::allocate_anywhere().
If we do not mark these ranges as reserved, RangeAllocator might later
give us addresses that overlap these, which then causes an assertion
failure in the SoftMMU. This behavior led to recurring CI failures, and
sometimes made programs as simple as `/bin/true` fail.
Fixes "Crash 1" reported in #9104
Most other syscalls pass address arguments as `void*` instead of
`uintptr_t`, so let's do that here too. Besides improving consistency,
this commit makes `strace` correctly pretty-print these arguments in
hex.
This feature was introduced in version 4.17 of the Linux kernel, and
while it's not specified by POSIX, I think it will be a nice addition to
our system.
MAP_FIXED_NOREPLACE provides a less error-prone alternative to
MAP_FIXED: while regular fixed mappings would cause any intersecting
ranges to be unmapped, MAP_FIXED_NOREPLACE returns EEXIST instead. This
ensures that we don't corrupt our process's address space if something
is already at the requested address.
Note that the more portable way to do this is to use regular
MAP_ANONYMOUS, and check afterwards whether the returned address matches
what we wanted. This, however, has a large performance impact on
programs like Wine which try to reserve large portions of the address
space at once, as the non-matching addresses have to be unmapped
separately.
In order to reduce our reliance on __builtin_{ffs, clz, ctz, popcount},
this commit removes all calls to these functions and replaces them with
the equivalent functions in AK/BuiltinWrappers.h.
This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
We already asked the region about what its library name is, and we also
use that value when maybe constructing a path, so let's make the check
use that as well.
Long doubles are always at least 80 bits wide in memory and it suffices
if we can address these 80 bits, to mark the long double as NAN at the
end of an MMX instruction, so the additional magic using conditional
types is unnecessary.
