tinycc/tccrun.c
2010-04-24 03:28:54 -07:00

632 lines
17 KiB
C

/*
* TCC - Tiny C Compiler - Support for -run switch
*
* Copyright (c) 2001-2004 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "tcc.h"
#ifdef _WIN32
#define ucontext_t CONTEXT
#endif
static void set_pages_executable(void *ptr, unsigned long length);
static void set_exception_handler(void);
static int rt_get_caller_pc(uplong *paddr, ucontext_t *uc, int level);
static void rt_error(ucontext_t *uc, const char *fmt, ...);
static int tcc_relocate_ex(TCCState *s1, void *ptr);
/* ------------------------------------------------------------- */
/* Do all relocations (needed before using tcc_get_symbol())
Returns -1 on error. */
int tcc_relocate(TCCState *s1)
{
int ret;
#ifdef HAVE_SELINUX
char tmpfname[] = "/tmp/.tccrunXXXXXX";
int fd = mkstemp (tmpfname);
unlink (tmpfname); ftruncate (fd, 1000);
if ((ret= tcc_relocate_ex(s1,NULL)) < 0)return -1;
s1->mem_size=ret;
/* Use mmap instead of malloc for Selinux */
s1->write_mem = mmap (NULL, ret, PROT_READ|PROT_WRITE,
MAP_SHARED, fd, 0);
if(s1->write_mem == MAP_FAILED){
error("/tmp not writeable");
return -1;
}
s1->runtime_mem = mmap (NULL, ret, PROT_READ|PROT_EXEC,
MAP_SHARED, fd, 0);
if(s1->runtime_mem == MAP_FAILED){
error("/tmp not executable");
return -1;
}
ret = tcc_relocate_ex(s1, s1->write_mem);
#else
ret = tcc_relocate_ex(s1, NULL);
if (-1 != ret) {
s1->runtime_mem = tcc_malloc(ret);
ret = tcc_relocate_ex(s1, s1->runtime_mem);
}
#endif
return ret;
}
/* launch the compiled program with the given arguments */
int tcc_run(TCCState *s1, int argc, char **argv)
{
int (*prog_main)(int, char **);
if (tcc_relocate(s1) < 0)
return -1;
prog_main = tcc_get_symbol_err(s1, "main");
#ifdef CONFIG_TCC_BACKTRACE
if (s1->do_debug)
set_exception_handler();
#endif
#ifdef CONFIG_TCC_BCHECK
if (s1->do_bounds_check) {
void (*bound_init)(void);
void (*bound_exit)(void);
int ret;
/* set error function */
rt_bound_error_msg = tcc_get_symbol_err(s1, "__bound_error_msg");
rt_prog_main = prog_main;
/* XXX: use .init section so that it also work in binary ? */
bound_init = tcc_get_symbol_err(s1, "__bound_init");
bound_exit = tcc_get_symbol_err(s1, "__bound_exit");
bound_init();
ret = (*prog_main)(argc, argv);
bound_exit();
return ret;
}
#endif
#ifdef TCC_TARGET_PE
{
unsigned char *p = tcc_get_symbol(s1, "tinyc_no_getbp");
if (p) *p = 0;
}
#endif
return (*prog_main)(argc, argv);
}
/* relocate code. Return -1 on error, required size if ptr is NULL,
otherwise copy code into buffer passed by the caller */
static int tcc_relocate_ex(TCCState *s1, void *ptr)
{
Section *s;
unsigned long offset, length;
uplong mem;
int i;
if (0 == s1->runtime_added) {
s1->runtime_added = 1;
s1->nb_errors = 0;
#ifdef TCC_TARGET_PE
pe_output_file(s1, NULL);
#else
tcc_add_runtime(s1);
relocate_common_syms();
tcc_add_linker_symbols(s1);
build_got_entries(s1);
#endif
if (s1->nb_errors)
return -1;
}
offset = 0, mem = (uplong)ptr;
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (0 == (s->sh_flags & SHF_ALLOC))
continue;
length = s->data_offset;
s->sh_addr = mem ? (mem + offset + 15) & ~15 : 0;
offset = (offset + length + 15) & ~15;
}
offset += 16;
/* relocate symbols */
relocate_syms(s1, 1);
if (s1->nb_errors)
return -1;
#if defined TCC_TARGET_X86_64 && !defined TCC_TARGET_PE
s1->runtime_plt_and_got_offset = 0;
s1->runtime_plt_and_got = (char *)(mem + offset);
/* double the size of the buffer for got and plt entries
XXX: calculate exact size for them? */
offset *= 2;
#endif
if (0 == mem)
return offset;
/* relocate each section */
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (s->reloc)
relocate_section(s1, s);
}
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (0 == (s->sh_flags & SHF_ALLOC))
continue;
length = s->data_offset;
// printf("%-12s %08x %04x\n", s->name, s->sh_addr, length);
ptr = (void*)(uplong)s->sh_addr;
if (NULL == s->data || s->sh_type == SHT_NOBITS)
memset(ptr, 0, length);
else
memcpy(ptr, s->data, length);
/* mark executable sections as executable in memory */
if (s->sh_flags & SHF_EXECINSTR)
set_pages_executable(ptr, length);
}
#if defined TCC_TARGET_X86_64 && !defined TCC_TARGET_PE
set_pages_executable(s1->runtime_plt_and_got,
s1->runtime_plt_and_got_offset);
#endif
return 0;
}
/* ------------------------------------------------------------- */
/* allow to run code in memory */
static void set_pages_executable(void *ptr, unsigned long length)
{
#ifdef _WIN32
unsigned long old_protect;
VirtualProtect(ptr, length, PAGE_EXECUTE_READWRITE, &old_protect);
#else
unsigned long start, end;
start = (uplong)ptr & ~(PAGESIZE - 1);
end = (uplong)ptr + length;
end = (end + PAGESIZE - 1) & ~(PAGESIZE - 1);
mprotect((void *)start, end - start, PROT_READ | PROT_WRITE | PROT_EXEC);
#endif
}
/* ------------------------------------------------------------- */
#ifdef CONFIG_TCC_BACKTRACE
/* print the position in the source file of PC value 'pc' by reading
the stabs debug information */
static uplong rt_printline(uplong wanted_pc)
{
Stab_Sym *sym, *sym_end;
char func_name[128], last_func_name[128];
unsigned long func_addr, last_pc, pc;
const char *incl_files[INCLUDE_STACK_SIZE];
int incl_index, len, last_line_num, i;
const char *str, *p;
fprintf(stderr, "0x%08lx:", (unsigned long)wanted_pc);
func_name[0] = '\0';
func_addr = 0;
incl_index = 0;
last_func_name[0] = '\0';
last_pc = 0xffffffff;
last_line_num = 1;
sym = (Stab_Sym *)stab_section->data + 1;
sym_end = (Stab_Sym *)(stab_section->data + stab_section->data_offset);
while (sym < sym_end) {
switch(sym->n_type) {
/* function start or end */
case N_FUN:
if (sym->n_strx == 0) {
/* we test if between last line and end of function */
pc = sym->n_value + func_addr;
if (wanted_pc >= last_pc && wanted_pc < pc)
goto found;
func_name[0] = '\0';
func_addr = 0;
} else {
str = stabstr_section->data + sym->n_strx;
p = strchr(str, ':');
if (!p) {
pstrcpy(func_name, sizeof(func_name), str);
} else {
len = p - str;
if (len > sizeof(func_name) - 1)
len = sizeof(func_name) - 1;
memcpy(func_name, str, len);
func_name[len] = '\0';
}
func_addr = sym->n_value;
}
break;
/* line number info */
case N_SLINE:
pc = sym->n_value + func_addr;
if (wanted_pc >= last_pc && wanted_pc < pc)
goto found;
last_pc = pc;
last_line_num = sym->n_desc;
/* XXX: slow! */
strcpy(last_func_name, func_name);
break;
/* include files */
case N_BINCL:
str = stabstr_section->data + sym->n_strx;
add_incl:
if (incl_index < INCLUDE_STACK_SIZE) {
incl_files[incl_index++] = str;
}
break;
case N_EINCL:
if (incl_index > 1)
incl_index--;
break;
case N_SO:
if (sym->n_strx == 0) {
incl_index = 0; /* end of translation unit */
} else {
str = stabstr_section->data + sym->n_strx;
/* do not add path */
len = strlen(str);
if (len > 0 && str[len - 1] != '/')
goto add_incl;
}
break;
}
sym++;
}
/* second pass: we try symtab symbols (no line number info) */
incl_index = 0;
{
ElfW(Sym) *sym, *sym_end;
int type;
sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset);
for(sym = (ElfW(Sym) *)symtab_section->data + 1;
sym < sym_end;
sym++) {
type = ELFW(ST_TYPE)(sym->st_info);
if (type == STT_FUNC) {
if (wanted_pc >= sym->st_value &&
wanted_pc < sym->st_value + sym->st_size) {
pstrcpy(last_func_name, sizeof(last_func_name),
strtab_section->data + sym->st_name);
func_addr = sym->st_value;
goto found;
}
}
}
}
/* did not find any info: */
fprintf(stderr, " ???\n");
return 0;
found:
if (last_func_name[0] != '\0') {
fprintf(stderr, " %s()", last_func_name);
}
if (incl_index > 0) {
fprintf(stderr, " (%s:%d",
incl_files[incl_index - 1], last_line_num);
for(i = incl_index - 2; i >= 0; i--)
fprintf(stderr, ", included from %s", incl_files[i]);
fprintf(stderr, ")");
}
fprintf(stderr, "\n");
return func_addr;
}
/* emit a run time error at position 'pc' */
static void rt_error(ucontext_t *uc, const char *fmt, ...)
{
va_list ap;
uplong pc;
int i;
va_start(ap, fmt);
fprintf(stderr, "Runtime error: ");
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
for(i=0;i<num_callers;i++) {
if (rt_get_caller_pc(&pc, uc, i) < 0)
break;
if (i == 0)
fprintf(stderr, "at ");
else
fprintf(stderr, "by ");
pc = rt_printline(pc);
if (pc == (uplong)rt_prog_main && pc)
break;
}
exit(255);
va_end(ap);
}
/* ------------------------------------------------------------- */
#ifndef _WIN32
/* signal handler for fatal errors */
static void sig_error(int signum, siginfo_t *siginf, void *puc)
{
ucontext_t *uc = puc;
switch(signum) {
case SIGFPE:
switch(siginf->si_code) {
case FPE_INTDIV:
case FPE_FLTDIV:
rt_error(uc, "division by zero");
break;
default:
rt_error(uc, "floating point exception");
break;
}
break;
case SIGBUS:
case SIGSEGV:
if (rt_bound_error_msg && *rt_bound_error_msg)
rt_error(uc, *rt_bound_error_msg);
else
rt_error(uc, "dereferencing invalid pointer");
break;
case SIGILL:
rt_error(uc, "illegal instruction");
break;
case SIGABRT:
rt_error(uc, "abort() called");
break;
default:
rt_error(uc, "caught signal %d", signum);
break;
}
exit(255);
}
/* Generate a stack backtrace when a CPU exception occurs. */
static void set_exception_handler(void)
{
struct sigaction sigact;
/* install TCC signal handlers to print debug info on fatal
runtime errors */
sigact.sa_flags = SA_SIGINFO | SA_RESETHAND;
sigact.sa_sigaction = sig_error;
sigemptyset(&sigact.sa_mask);
sigaction(SIGFPE, &sigact, NULL);
sigaction(SIGILL, &sigact, NULL);
sigaction(SIGSEGV, &sigact, NULL);
sigaction(SIGBUS, &sigact, NULL);
sigaction(SIGABRT, &sigact, NULL);
}
/* ------------------------------------------------------------- */
#ifdef __i386__
/* fix for glibc 2.1 */
#ifndef REG_EIP
#define REG_EIP EIP
#define REG_EBP EBP
#endif
/* return the PC at frame level 'level'. Return non zero if not found */
static int rt_get_caller_pc(unsigned long *paddr, ucontext_t *uc, int level)
{
unsigned long fp;
int i;
if (level == 0) {
#if defined(__FreeBSD__)
*paddr = uc->uc_mcontext.mc_eip;
#elif defined(__dietlibc__)
*paddr = uc->uc_mcontext.eip;
#else
*paddr = uc->uc_mcontext.gregs[REG_EIP];
#endif
return 0;
} else {
#if defined(__FreeBSD__)
fp = uc->uc_mcontext.mc_ebp;
#elif defined(__dietlibc__)
fp = uc->uc_mcontext.ebp;
#else
fp = uc->uc_mcontext.gregs[REG_EBP];
#endif
for(i=1;i<level;i++) {
/* XXX: check address validity with program info */
if (fp <= 0x1000 || fp >= 0xc0000000)
return -1;
fp = ((unsigned long *)fp)[0];
}
*paddr = ((unsigned long *)fp)[1];
return 0;
}
}
/* ------------------------------------------------------------- */
#elif defined(__x86_64__)
/* return the PC at frame level 'level'. Return non zero if not found */
static int rt_get_caller_pc(unsigned long *paddr,
ucontext_t *uc, int level)
{
unsigned long fp;
int i;
if (level == 0) {
/* XXX: only support linux */
#if defined(__FreeBSD__)
*paddr = uc->uc_mcontext.mc_rip;
#else
*paddr = uc->uc_mcontext.gregs[REG_RIP];
#endif
return 0;
} else {
#if defined(__FreeBSD__)
fp = uc->uc_mcontext.mc_rbp;
#else
fp = uc->uc_mcontext.gregs[REG_RBP];
#endif
for(i=1;i<level;i++) {
/* XXX: check address validity with program info */
if (fp <= 0x1000)
return -1;
fp = ((unsigned long *)fp)[0];
}
*paddr = ((unsigned long *)fp)[1];
return 0;
}
}
/* ------------------------------------------------------------- */
#else
#warning add arch specific rt_get_caller_pc()
static int rt_get_caller_pc(unsigned long *paddr,
ucontext_t *uc, int level)
{
return -1;
}
#endif /* !__i386__ */
/* ------------------------------------------------------------- */
#else /* WIN32 */
static long __stdcall cpu_exception_handler(EXCEPTION_POINTERS *ex_info)
{
CONTEXT *uc = ex_info->ContextRecord;
/*
EXCEPTION_RECORD *er = ex_info->ExceptionRecord;
printf("CPU exception: code=%08lx addr=%p\n",
er->ExceptionCode, er->ExceptionAddress);
*/
if (rt_bound_error_msg && *rt_bound_error_msg)
rt_error(uc, *rt_bound_error_msg);
else
rt_error(uc, "dereferencing invalid pointer");
exit(255);
//return EXCEPTION_CONTINUE_SEARCH;
}
/* Generate a stack backtrace when a CPU exception occurs. */
static void set_exception_handler(void)
{
SetUnhandledExceptionFilter(cpu_exception_handler);
}
#ifdef _WIN64
#define Eip Rip
#define Ebp Rbp
#endif
/* return the PC at frame level 'level'. Return non zero if not found */
static int rt_get_caller_pc(uplong *paddr, CONTEXT *uc, int level)
{
uplong fp;
int i;
if (level == 0) {
*paddr = uc->Eip;
return 0;
} else {
fp = uc->Ebp;
for(i=1;i<level;i++) {
/* XXX: check address validity with program info */
if (fp <= 0x1000 || fp >= 0xc0000000)
return -1;
fp = ((uplong*)fp)[0];
}
*paddr = ((uplong*)fp)[1];
return 0;
}
}
#undef Eip
#undef Ebp
#endif /* _WIN32 */
#endif /* CONFIG_TCC_BACKTRACE */
/* ------------------------------------------------------------- */
#ifdef CONFIG_TCC_STATIC
#define RTLD_LAZY 0x001
#define RTLD_NOW 0x002
#define RTLD_GLOBAL 0x100
#define RTLD_DEFAULT NULL
/* dummy function for profiling */
void *dlopen(const char *filename, int flag)
{
return NULL;
}
void dlclose(void *p)
{
}
/*
const char *dlerror(void)
{
return "error";
}
*/
typedef struct TCCSyms {
char *str;
void *ptr;
} TCCSyms;
#define TCCSYM(a) { #a, &a, },
/* add the symbol you want here if no dynamic linking is done */
static TCCSyms tcc_syms[] = {
#if !defined(CONFIG_TCCBOOT)
TCCSYM(printf)
TCCSYM(fprintf)
TCCSYM(fopen)
TCCSYM(fclose)
#endif
{ NULL, NULL },
};
void *resolve_sym(TCCState *s1, const char *symbol)
{
TCCSyms *p;
p = tcc_syms;
while (p->str != NULL) {
if (!strcmp(p->str, symbol))
return p->ptr;
p++;
}
return NULL;
}
#elif !defined(_WIN32)
void *resolve_sym(TCCState *s1, const char *sym)
{
return dlsym(RTLD_DEFAULT, sym);
}
#endif /* CONFIG_TCC_STATIC */
/* ------------------------------------------------------------- */