Casting pid to ::pid_t when invoking syscall.

[chaoren]

Summary

syscalls involving pid/tid on 32 bit binaries are failing with
"Invalid argument" because the uint64_t arguments are too wide.

[clayborg]

Sounds like you don't have the function prototype for syscall? Otherwise there would be a conversion to the correct type. You can fix this with a static_cast like you did, but in reality this shouldn't happen unless you don't have the syscall prototype.

[chaoren]

extern long int syscall (long int sysno, ...) THROW;

Variadic arguments.

[clayborg]

Looks good then, thanks for making sure.

source/Plugins/Process/Linux/NativeProcessLinux.cpp

 
 // Support hardware breakpoints in case it has not been defined
 #ifndef TRAP_HWBKPT
   #define TRAP_HWBKPT 4
 #endif
 
 // Try to define a macro to encapsulate the tgkill syscall
 // fall back on kill() if tgkill isn't available
-#define tgkill(pid, tid, sig)  syscall(SYS_tgkill, pid, tid, sig)
+#define tgkill(pid, tid, sig) \
+    syscall(SYS_tgkill, static_cast<::pid_t>(pid), static_cast<::pid_t>(tid), sig)
 
 // We disable the tracing of ptrace calls for integration builds to
 // avoid the additional indirection and checks.
 #ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
 #define PTRACE(req, pid, addr, data, data_size, error) \
     PtraceWrapper((req), (pid), (addr), (data), (data_size), (error), #req, __FILE__, __LINE__)
 #else
 #define PTRACE(req, pid, addr, data, data_size, error) \

source/Plugins/Process/Linux/ProcessMonitor.cpp

 
 // Support hardware breakpoints in case it has not been defined
 #ifndef TRAP_HWBKPT
   #define TRAP_HWBKPT 4
 #endif
 
 // Try to define a macro to encapsulate the tgkill syscall
 // fall back on kill() if tgkill isn't available
-#define tgkill(pid, tid, sig)  syscall(SYS_tgkill, pid, tid, sig)
+#define tgkill(pid, tid, sig) \
+    syscall(SYS_tgkill, static_cast<::pid_t>(pid), static_cast<::pid_t>(tid), sig)
 
 using namespace lldb_private;
 
 // FIXME: this code is host-dependent with respect to types and
 // endianness and needs to be fixed.  For example, lldb::addr_t is
 // hard-coded to uint64_t, but on a 32-bit Linux host, ptrace requires
 // 32-bit pointer arguments.  This code uses casts to work around the
 // problem.