Switch syscall(2)/__syscall(2) calls to libc calls on NetBSD
Summary:
When possible, switch syscall(2)/__syscall(2) calls
to direct calls of internal libc symbols.
Add a new function to detect address of a libc
symbol of a function that could be intercepted.
With the address detector in GetRealLibcAddress(),
an optional interceptor of libc call will be bypassed.
The original approach with syscall(2)/__syscall(2)
wasn't portable across supported ABIs and CPU
architectures. The indirect syscall interface is
also a candidate for removal in future revisions
of NetBSD, as the C language ABI is not a good
domain for serialization of arbitrary functions
arguments.
Switch the following functions to libc calls:
- internal_mmap()
- internal_munmap()
- internal_mprotect()
- internal_close()
- internal_open()
- internal_read()
- internal_write()
- internal_ftruncate()
- internal_stat()
- internal_lstat()
- internal_fstat()
- internal_dup2()
- internal_readlink()
- internal_unlink()
- internal_rename()
- internal_sched_yield()
- internal__exit()
- internal_sleep()
- internal_execve()
- NanoTime()
- internal_clock_gettime()
- internal_waitpid()
- internal_getpid()
- internal_getppid()
- internal_getdents()
- internal_lseek()
- internal_sigaltstack()
- internal_fork()
- internal_sigprocmask()
- internal_sysctl()
- internal_sigemptyset()
- internal_sigfillset()
- GetTid()
- TgKill()
This revision leaves room for refactoring in subsequent commits.
Reviewers: vitalybuka, kcc, joerg
Reviewed By: vitalybuka
Subscribers: mgorny, fedor.sergeev, jfb, loverszhaokai, devnexen, kubamracek, llvm-commits, ro, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D51419
llvm-svn: 343523