[COMMIT osv master] syscall: add msync syscall

[Commit Bot]

From: Waldemar Kozaczuk <jwkoz...@gmail.com>
Committer: Waldemar Kozaczuk <jwkoz...@gmail.com>
Branch: master

syscall: add msync syscall

This allows tst-mmap.cc to execute successfully on OSv with Linux
dynamically linker.

Signed-off-by: Waldemar Kozaczuk <jwkoz...@gmail.com>

---
diff --git a/linux.cc b/linux.cc
--- a/linux.cc
+++ b/linux.cc
@@ -704,6 +704,7 @@ TRACEPOINT(trace_syscall_sys_clone, "%d <= 0x%x 0x%x %p %p %lu", int, unsigned l
TRACEPOINT(trace_syscall_sys_clone3, "%d <= %p %lu", int, struct clone_args *, size_t);
#endif
TRACEPOINT(trace_syscall_prlimit64, "%d <= %u %d %p %p", int, pid_t, int, const struct rlimit *, struct rlimit *);
+TRACEPOINT(trace_syscall_msync, "%d <= 0x%x %lu %d", int, void *, size_t, int);

OSV_LIBC_API long syscall(long number, ...)
{
@@ -850,6 +851,7 @@ OSV_LIBC_API long syscall(long number, ...)
SYSCALL2(sys_clone3, struct clone_args *, size_t);
#endif
SYSCALL4(prlimit64, pid_t, int, const struct rlimit *, struct rlimit *);
+ SYSCALL3(msync, void *, size_t, int);
}

debug_always("syscall(): unimplemented system call %d\n", number);