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#include <bits/ensure.h>
#include <bits/posix/posix_signal.h>
#include <keyronex/syscall.h>
#include <mlibc/all-sysdeps.hpp>
#include <mlibc/debug.hpp>
#include <mlibc/elf/startup.h>
#include <stdint.h>
#include <stdlib.h>
// defined by the POSIX library
void __mlibc_initLocale();
extern "C" uintptr_t *__dlapi_entrystack();
extern char **environ;
static mlibc::exec_stack_data __mlibc_stack_data;
struct LibraryGuard {
LibraryGuard();
};
static LibraryGuard guard;
LibraryGuard::LibraryGuard()
{
__mlibc_initLocale();
// Parse the exec() stack.
mlibc::parse_exec_stack(__dlapi_entrystack(), &__mlibc_stack_data);
mlibc::set_startup_data(__mlibc_stack_data.argc,
__mlibc_stack_data.argv, __mlibc_stack_data.envp);
}
namespace mlibc {
int
sys_sigentry(void *sigentry)
{
uintptr_t ret = syscall1(kPXSysSigEntry, (uintptr_t)sigentry, NULL);
if (int e = sc_error(ret); e)
return e;
return 0;
}
[[noreturn]] int
sys_sigreturn(ucontext_t *context)
{
syscall1(kPXSysSigReturn, (uintptr_t)context, NULL);
__builtin_unreachable();
}
}
static void
do_stacktrace(ucontext_t *ctx)
{
size_t *base_ptr = (size_t *)ctx->uc_mcontext.gregs[REG_RBP];
mlibc::infoLogger() << "Stacktrace:" << frg::endlog;
mlibc::infoLogger() << " [" << (void *)ctx->uc_mcontext.gregs[REG_RIP]
<< "]" << frg::endlog;
for (;;) {
size_t old_bp = base_ptr[0];
size_t ret_addr = base_ptr[1];
if (!ret_addr)
break;
mlibc::infoLogger()
<< " [" << (void *)ret_addr << "]" << frg::endlog;
if (!old_bp)
break;
base_ptr = (size_t *)old_bp;
}
}
static void
__mlibc_sigentry(int which, siginfo_t *siginfo, void *handler,
bool is_sigaction, ucontext_t *ret_context)
{
if ((uintptr_t)handler == (uintptr_t)SIG_DFL) {
mlibc::infoLogger()
<< "mlibc: Unhandled signal " << which << frg::endlog;
do_stacktrace(ret_context);
mlibc::sys_exit(128 + which);
} else if ((uintptr_t)handler == (uintptr_t)SIG_IGN) {
/* epsilon */
} else {
if (is_sigaction)
((void (*)(int, siginfo_t *, void *))handler)(which,
siginfo, ret_context);
else
((void (*)(int))handler)(which);
}
mlibc::sys_sigreturn(ret_context);
__builtin_unreachable();
}
extern "C" void
__mlibc_entry(int (*main_fn)(int argc, char *argv[], char *env[]))
{
/* communicate the signal handler entry point to the kernel */
mlibc::sys_sigentry((void *)__mlibc_sigentry);
// TODO: call __dlapi_enter, otherwise static builds will break (see
// Linux sysdeps)
auto result = main_fn(__mlibc_stack_data.argc, __mlibc_stack_data.argv,
environ);
exit(result);
}
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