This patch makes strto{u,}l{l,}() behave more to-spec about endptr.
"If endptr is not NULL, strtoull stores the address of the first invalid
character in *endptr."
This fixes the behavior for several inputs:
- '-0' (shouldn't work but was accepted)
- '+3' (shouldn't work but was accepted)
- '13835058055282163712' (should work but returned 9223372036854775807 with errno=ERANGE)
This strtod implementation is not perfectly accurate, as evidenced by the test
(accuracy_strtod.cpp), but it is sufficiently close (up to 8 eps).
The main sources of inaccuracy are:
- Highly repeated division/multiplication by 'base'
(Each operation brings a multiplicative error of 1+2^-53.)
- Loss during the initial conversion from long long to double (most prominently,
69294956446009195 should first be rounded to 69294956446009200 and then
converted to 69294956446009200.0 and then divided by ten, yielding
6929495644600920.0. Currently, it converts first to double, can't represent
69294956446009195.0, and instead represents 69294956446009190, which
eventually yields 6929495644600919.0. Close, but technically wrong.)
I believe that these issues can be fixed by rewriting the part at and after
double value = digits.number();
and that the loss before that is acceptable.
Specifically, losing the exact exponent on overflow is obviously fine.
The only other loss occurs when the significant digits overflow a 'long long'.
But these store 64(-7ish) bits, and the mantissa of a double only stores 52 bits.
With a bit more thinking, one could probably get the error down to 1 or 2 eps.
(But not better.)
Fixes#1979.
In f4302b58fb, the kernel-side syscalls (e.g Process::sys$getsockname)
were updated to use SC_get{sock,peer}name_params, but the libc
functions were not updated.
This commit implements the getprotoent() family of functions, including
getprotoent()
getprotobyname()
getprotobynumber()
setprotoent()
endprotoent()
This implementation is very similar to the getservent family of functions,
which is what led to the discovery of a bug in the process of reading the aliases.
The ByteBuffer for the alias strings didn't include a null terminating character,
this was fixed for both the protoent and servent family of functions by appending a
null character to the end of them before adding them to the alias lists.
fix all requested changes including:
- remove explicit vector initialization
- change keep_service_file_open to boolean
- closing service file on seek error
- change C level char allocation to use ByteBuffer instead
- simplified getservby* loops to a single loop
- change fill_getserv_buffers return to early-return style
This commit implements the getservent family of functions:
getservent()
setservent()
endservent()
getservbyname()
getservbyport()
for accessing the /etc/services file.
This commit has addressed the issues identified by utilizing more C++ structures,
addressing unchecked error possibilities, strncpy bounds checking, and other issues
found in the initial pull request
Instead of pushing the message, file name, line# and function name
separately, we now mash the message, file name and line# into a string
constant and pass that.
This means that the failure path only has to push a single address onto
the stack, reducing the code size and causing the compiler to inline
many more functions containing an assertions (e.g RefPtr::operator*())
Obviously if you wanted minimal size, you could turn assertions off
entirely, but I really like running with assertions, so let's make
a little effort to reduce their impact. :^)
The syscall wrapper for ptrace needs to return the peeked value when
using PT_PEEK.
Because of this, the user has to check errno to detect an error in
PT_PEEK.
This commit changes the actual syscall's interface (only for PT_PEEK) to
allow the syscall wrapper to detect an error and change errno.
PT_SETTREGS sets the regsiters of the traced thread. It can only be
used when the tracee is stopped.
Also, refactor ptrace.
The implementation was getting long and cluttered the alraedy large
Process.cpp file.
This commit moves the bulk of the implementation to Kernel/Ptrace.cpp,
and factors out peek & poke to separate methods of the Process class.
PT_POKE writes a single word to the tracee's address space.
Some caveats:
- If the user requests to write to an address in a read-only region, we
temporarily change the page's protections to allow it.
- If the user requests to write to a region that's backed by a
SharedInodeVMObject, we replace the vmobject with a PrivateIndoeVMObject.
We now use minherit(MAP_INHERIT_ZERO) to create a gettid() cache that
is automatically invalidated on fork(). This is needed since the TID
will be different in a forked child, and so we can't have a stale
cached TID lying around.
This is a gigantic speedup for LibJS (and everyone else too) :^)
This patch adds the minherit() syscall originally invented by OpenBSD.
Only the MAP_INHERIT_ZERO mode is supported for now. If set on an mmap
region, that region will be zeroed out on fork().
These validate_elf_* methods really had no business being static
methods of ELF::Image. Now that the ELF namespace exists, it makes
sense to just move them to be free functions in the namespace.
This patch adds a way for a socket to ask to be routed through a
specific interface.
Currently, this option only applies to sending, however, it should also
apply to receiving...somehow :^)
This commit adds a basic implementation of
the ptrace syscall, which allows one process
(the tracer) to control another process (the tracee).
While a process is being traced, it is stopped whenever a signal is
received (other than SIGCONT).
The tracer can start tracing another thread with PT_ATTACH,
which causes the tracee to stop.
From there, the tracer can use PT_CONTINUE
to continue the execution of the tracee,
or use other request codes (which haven't been implemented yet)
to modify the state of the tracee.
Additional request codes are PT_SYSCALL, which causes the tracee to
continue exection but stop at the next entry or exit from a syscall,
and PT_GETREGS which fethces the last saved register set of the tracee
(can be used to inspect syscall arguments and return value).
A special request code is PT_TRACE_ME, which is issued by the tracee
and causes it to stop when it calls execve and wait for the
tracer to attach.
