diff options
Diffstat (limited to 'upb/pb/compile_decoder_x64.c')
| -rw-r--r-- | upb/pb/compile_decoder_x64.c | 510 |
1 files changed, 0 insertions, 510 deletions
diff --git a/upb/pb/compile_decoder_x64.c b/upb/pb/compile_decoder_x64.c deleted file mode 100644 index fd541a4..0000000 --- a/upb/pb/compile_decoder_x64.c +++ /dev/null @@ -1,510 +0,0 @@ -/* -** Driver code for the x64 JIT compiler. -*/ - -/* Needed to ensure we get defines like MAP_ANON. */ -#define _GNU_SOURCE - -#include <dlfcn.h> -#include <stdio.h> -#include <sys/mman.h> -#include <unistd.h> -#include "upb/msg.h" -#include "upb/pb/decoder.h" -#include "upb/pb/decoder.int.h" -#include "upb/pb/varint.int.h" - -/* To debug the JIT: - * - * 1. Uncomment: - * #define UPB_JIT_LOAD_SO - * - * Note: this mode requires that we can shell out to gcc. - * - * 2. Run the test locally. This will load the JIT code by building a - * .so (/tmp/upb-jit-code.so) and using dlopen, so more of the tooling will - * work properly (like GDB). - * - * IF YOU ALSO WANT AUTOMATIC JIT DEBUG OUTPUT: - * - * 3. Run: upb/pb/make-gdb-script.rb > script.gdb. This reads - * /tmp/upb-jit-code.so as input and generates a GDB script that is specific - * to this jit code. - * - * 4. Run: gdb --command=script.gdb --args path/to/test - * This will drop you to a GDB prompt which you can now use normally. - * But when you run the test it will print a message to stdout every time - * the JIT executes assembly for a particular bytecode. Sample output: - * - * X.enterjit bytes=18 - * buf_ofs=1 data_rem=17 delim_rem=-2 X.0x6.OP_PARSE_DOUBLE - * buf_ofs=9 data_rem=9 delim_rem=-10 X.0x7.OP_CHECKDELIM - * buf_ofs=9 data_rem=9 delim_rem=-10 X.0x8.OP_TAG1 - * X.0x3.dispatch.DecoderTest - * X.parse_unknown - * X.0x3.dispatch.DecoderTest - * X.decode_unknown_tag_fallback - * X.exitjit - * - * This output should roughly correspond to the output that the bytecode - * interpreter emits when compiled with UPB_DUMP_BYTECODE (modulo some - * extra JIT-specific output). */ - -/* These defines are necessary for DynASM codegen. - * See dynasm/dasm_proto.h for more info. */ -#define Dst_DECL jitcompiler *jc -#define Dst_REF (jc->dynasm) -#define Dst (jc) - -/* In debug mode, make DynASM do internal checks (must be defined before any - * dasm header is included. */ -#ifndef NDEBUG -#define DASM_CHECKS -#endif - -#ifndef MAP_ANONYMOUS -#define MAP_ANONYMOUS MAP_ANON -#endif - -typedef struct { - mgroup *group; - uint32_t *pc; - - /* This pointer is allocated by dasm_init() and freed by dasm_free(). */ - struct dasm_State *dynasm; - - /* Maps some key (an arbitrary void*) to a pclabel. - * - * The pclabel represents a location in the generated code -- DynASM exposes - * a pclabel -> (machine code offset) lookup function. - * - * The key can be anything. There are two main kinds of keys: - * - bytecode location -- the void* points to the bytecode instruction - * itself. We can then use this to generate jumps to this instruction. - * - other object (like dispatch table). We use these to represent parts - * of the generated code that do not exactly correspond to a bytecode - * instruction. */ - upb_inttable jmptargets; - -#ifndef NDEBUG - /* Like jmptargets, but members are present in the table when they have had - * define_jmptarget() (as opposed to jmptarget) called. Used to verify that - * define_jmptarget() is called exactly once for every target. - * The value is ignored. */ - upb_inttable jmpdefined; - - /* For checking that two asmlabels aren't defined for the same byte. */ - int lastlabelofs; -#endif - -#ifdef UPB_JIT_LOAD_SO - /* For marking labels that should go into the generated code. - * Maps pclabel -> char* label (string is owned by the table). */ - upb_inttable asmlabels; -#endif - - /* The total number of pclabels currently defined. - * Note that this contains both jmptargets and asmlabels, which both use - * pclabels but for different purposes. */ - uint32_t pclabel_count; - - /* Used by DynASM to store globals. */ - void **globals; -} jitcompiler; - -/* Functions called by codegen. */ -static int jmptarget(jitcompiler *jc, const void *key); -static int define_jmptarget(jitcompiler *jc, const void *key); -static void asmlabel(jitcompiler *jc, const char *fmt, ...); -static int pcofs(jitcompiler* jc); -static int alloc_pclabel(jitcompiler *jc); - -#ifdef UPB_JIT_LOAD_SO -static char *upb_vasprintf(const char *fmt, va_list ap); -static char *upb_asprintf(const char *fmt, ...); -#endif - -#include "third_party/dynasm/dasm_proto.h" -#include "third_party/dynasm/dasm_x86.h" -#include "upb/pb/compile_decoder_x64.h" - -static jitcompiler *newjitcompiler(mgroup *group) { - jitcompiler *jc = malloc(sizeof(jitcompiler)); - jc->group = group; - jc->pclabel_count = 0; - upb_inttable_init(&jc->jmptargets, UPB_CTYPE_UINT32); -#ifndef NDEBUG - jc->lastlabelofs = -1; - upb_inttable_init(&jc->jmpdefined, UPB_CTYPE_BOOL); -#endif -#ifdef UPB_JIT_LOAD_SO - upb_inttable_init(&jc->asmlabels, UPB_CTYPE_PTR); -#endif - jc->globals = malloc(UPB_JIT_GLOBAL__MAX * sizeof(*jc->globals)); - - dasm_init(jc, 1); - dasm_setupglobal(jc, jc->globals, UPB_JIT_GLOBAL__MAX); - dasm_setup(jc, upb_jit_actionlist); - - return jc; -} - -static void freejitcompiler(jitcompiler *jc) { -#ifdef UPB_JIT_LOAD_SO - upb_inttable_iter i; - upb_inttable_begin(&i, &jc->asmlabels); - for (; !upb_inttable_done(&i); upb_inttable_next(&i)) { - free(upb_value_getptr(upb_inttable_iter_value(&i))); - } - upb_inttable_uninit(&jc->asmlabels); -#endif -#ifndef NDEBUG - upb_inttable_uninit(&jc->jmpdefined); -#endif - upb_inttable_uninit(&jc->jmptargets); - dasm_free(jc); - free(jc->globals); - free(jc); -} - -#ifdef UPB_JIT_LOAD_SO - -/* Like sprintf except allocates the string, which is returned and owned by the - * caller. - * - * Like the GNU extension asprintf(), except we abort on error (since this is - * only for debugging). */ -static char *upb_vasprintf(const char *fmt, va_list args) { - /* Run once to get the length of the string. */ - va_list args_copy; - va_copy(args_copy, args); - int len = _upb_vsnprintf(NULL, 0, fmt, args_copy); - va_end(args_copy); - - char *ret = malloc(len + 1); /* + 1 for NULL terminator. */ - if (!ret) abort(); - int written = _upb_vsnprintf(ret, len + 1, fmt, args); - UPB_ASSERT(written == len); - - return ret; -} - -static char *upb_asprintf(const char *fmt, ...) { - va_list args; - va_start(args, fmt); - char *ret = upb_vasprintf(fmt, args); - va_end(args); - return ret; -} - -#endif - -static int alloc_pclabel(jitcompiler *jc) { - int newpc = jc->pclabel_count++; - dasm_growpc(jc, jc->pclabel_count); - return newpc; -} - -static bool try_getjmptarget(jitcompiler *jc, const void *key, int *pclabel) { - upb_value v; - if (upb_inttable_lookupptr(&jc->jmptargets, key, &v)) { - *pclabel = upb_value_getuint32(v); - return true; - } else { - return false; - } -} - -/* Gets the pclabel for this bytecode location's jmptarget. Requires that the - * jmptarget() has been previously defined. */ -static int getjmptarget(jitcompiler *jc, const void *key) { - int pclabel = 0; - bool ok; - - UPB_ASSERT_DEBUGVAR(upb_inttable_lookupptr(&jc->jmpdefined, key, NULL)); - ok = try_getjmptarget(jc, key, &pclabel); - UPB_ASSERT(ok); - return pclabel; -} - -/* Returns a pclabel that serves as a jmp target for the given bytecode pointer. - * This should only be called for code that is jumping to the target; code - * defining the target should use define_jmptarget(). - * - * Creates/allocates a pclabel for this target if one does not exist already. */ -static int jmptarget(jitcompiler *jc, const void *key) { - // Optimizer sometimes can't figure out that initializing this is unnecessary. - int pclabel = 0; - if (!try_getjmptarget(jc, key, &pclabel)) { - pclabel = alloc_pclabel(jc); - upb_inttable_insertptr(&jc->jmptargets, key, upb_value_uint32(pclabel)); - } - return pclabel; -} - -/* Defines a pclabel associated with the given bytecode location. - * Must be called exactly once by the code that is generating the code for this - * bytecode. - * - * Must be called exactly once before bytecode generation is complete (this is a - * sanity check to make sure the label is defined exactly once). */ -static int define_jmptarget(jitcompiler *jc, const void *key) { -#ifndef NDEBUG - upb_inttable_insertptr(&jc->jmpdefined, key, upb_value_bool(true)); -#endif - return jmptarget(jc, key); -} - -/* Returns a bytecode pc offset relative to the beginning of the group's - * code. */ -static int pcofs(jitcompiler *jc) { - return jc->pc - jc->group->bytecode; -} - -/* Returns a machine code offset corresponding to the given key. - * Requires that this key was defined with define_jmptarget. */ -static int machine_code_ofs(jitcompiler *jc, const void *key) { - int pclabel = getjmptarget(jc, key); - /* Despite its name, this function takes a pclabel and returns the - * corresponding machine code offset. */ - return dasm_getpclabel(jc, pclabel); -} - -/* Returns a machine code offset corresponding to the given method-relative - * bytecode offset. Note that the bytecode offset is relative to the given - * method, but the returned machine code offset is relative to the beginning of - * *all* the machine code. */ -static int machine_code_ofs2(jitcompiler *jc, const upb_pbdecodermethod *method, - int pcofs) { - void *bc_target = jc->group->bytecode + method->code_base.ofs + pcofs; - return machine_code_ofs(jc, bc_target); -} - -/* Given a pcofs relative to this method's base, returns a machine code offset - * relative to jmptarget(dispatch->array) (which is used in jitdispatch as the - * machine code base for dispatch table lookups). */ -uint32_t dispatchofs(jitcompiler *jc, const upb_pbdecodermethod *method, - int pcofs) { - int mc_base = machine_code_ofs(jc, method->dispatch.array); - int mc_target = machine_code_ofs2(jc, method, pcofs); - int ret; - - UPB_ASSERT(mc_base > 0); - UPB_ASSERT(mc_target > 0); - ret = mc_target - mc_base; - UPB_ASSERT(ret > 0); - return ret; -} - -/* Rewrites the dispatch tables into machine code offsets. */ -static void patchdispatch(jitcompiler *jc) { - upb_inttable_iter i; - upb_inttable_begin(&i, &jc->group->methods); - for (; !upb_inttable_done(&i); upb_inttable_next(&i)) { - upb_pbdecodermethod *method = upb_value_getptr(upb_inttable_iter_value(&i)); - upb_inttable *dispatch = &method->dispatch; - upb_inttable_iter i2; - - method->is_native_ = true; - - /* Remove DISPATCH_ENDMSG -- only the bytecode interpreter needs it. - * And leaving it around will cause us to find field 0 improperly. */ - upb_inttable_remove(dispatch, DISPATCH_ENDMSG, NULL); - - upb_inttable_begin(&i2, dispatch); - for (; !upb_inttable_done(&i2); upb_inttable_next(&i2)) { - uintptr_t key = upb_inttable_iter_key(&i2); - uint64_t val = upb_value_getuint64(upb_inttable_iter_value(&i2)); - uint64_t newval; - bool ok; - if (key <= UPB_MAX_FIELDNUMBER) { - /* Primary slot. */ - uint64_t ofs; - uint8_t wt1; - uint8_t wt2; - upb_pbdecoder_unpackdispatch(val, &ofs, &wt1, &wt2); - - /* Update offset and repack. */ - ofs = dispatchofs(jc, method, ofs); - newval = upb_pbdecoder_packdispatch(ofs, wt1, wt2); - UPB_ASSERT((int64_t)newval > 0); - } else { - /* Secondary slot. Since we have 64 bits for the value, we use an - * absolute offset. */ - int mcofs = machine_code_ofs2(jc, method, val); - newval = (uint64_t)((char*)jc->group->jit_code + mcofs); - } - ok = upb_inttable_replace(dispatch, key, upb_value_uint64(newval)); - UPB_ASSERT(ok); - } - - /* Update entry point for this method to point at mc base instead of bc - * base. Set this only *after* we have patched the offsets - * (machine_code_ofs2() uses this). */ - method->code_base.ptr = (char*)jc->group->jit_code + machine_code_ofs(jc, method); - - { - upb_byteshandler *h = &method->input_handler_; - upb_byteshandler_setstartstr(h, upb_pbdecoder_startjit, NULL); - upb_byteshandler_setstring(h, jc->group->jit_code, method->code_base.ptr); - upb_byteshandler_setendstr(h, upb_pbdecoder_end, method); - } - } -} - -#ifdef UPB_JIT_LOAD_SO - -static void load_so(jitcompiler *jc) { - /* Dump to a .so file in /tmp and load that, so all the tooling works right - * (for example, debuggers and profilers will see symbol names for the JIT-ted - * code). This is the same goal of the GDB JIT code below, but the GDB JIT - * interface is only used/understood by GDB. Hopefully a standard will - * develop for registering JIT-ted code that all tools will recognize, - * rendering this obsolete. - * - * jc->asmlabels maps: - * pclabel -> char* label - * - * Use this to build mclabels, which maps: - * machine code offset -> char* label - * - * Then we can use mclabels to emit the labels as we iterate over the bytes we - * are outputting. */ - upb_inttable_iter i; - upb_inttable mclabels; - upb_inttable_init(&mclabels, UPB_CTYPE_PTR); - upb_inttable_begin(&i, &jc->asmlabels); - for (; !upb_inttable_done(&i); upb_inttable_next(&i)) { - upb_inttable_insert(&mclabels, - dasm_getpclabel(jc, upb_inttable_iter_key(&i)), - upb_inttable_iter_value(&i)); - } - - /* We write a .s file in text format, as input to the assembler. - * Then we run gcc to turn it into a .so file. - * - * The last "XXXXXX" will be replaced with something randomly generated by - * mkstmemp(). We don't add ".s" to this filename because it makes the string - * processing for mkstemp() and system() more complicated. */ - char s_filename[] = "/tmp/upb-jit-codeXXXXXX"; - int fd = mkstemp(s_filename); - FILE *f; - if (fd >= 0 && (f = fdopen(fd, "wb")) != NULL) { - uint8_t *jit_code = (uint8_t*)jc->group->jit_code; - size_t linelen = 0; - size_t i; - fputs(" .text\n\n", f); - for (i = 0; i < jc->group->jit_size; i++) { - upb_value v; - if (upb_inttable_lookup(&mclabels, i, &v)) { - const char *label = upb_value_getptr(v); - /* "X." makes our JIT syms recognizable as such, which we build into - * other tooling. */ - fprintf(f, "\n\nX.%s:\n", label); - fprintf(f, " .globl X.%s", label); - linelen = 1000; - } - if (linelen >= 77) { - linelen = fprintf(f, "\n .byte %u", jit_code[i]); - } else { - linelen += fprintf(f, ",%u", jit_code[i]); - } - } - fputs("\n", f); - fclose(f); - } else { - fprintf(stderr, "Error opening tmp file for JIT debug output.\n"); - abort(); - } - - /* This is exploitable if you have an adversary on your machine who can write - * to this tmp directory. But this is just for debugging so we don't worry - * too much about that. It shouldn't be prone to races against concurrent - * (non-adversarial) upb JIT's because we used mkstemp(). */ - char *cmd = upb_asprintf("gcc -shared -o %s.so -x assembler %s", s_filename, - s_filename); - if (system(cmd) != 0) { - fprintf(stderr, "Error compiling %s\n", s_filename); - abort(); - } - free(cmd); - - char *so_filename = upb_asprintf("%s.so", s_filename); - - /* Some convenience symlinks. - * This is racy, but just for convenience. */ - int ret; - unlink("/tmp/upb-jit-code.so"); - unlink("/tmp/upb-jit-code.s"); - ret = symlink(s_filename, "/tmp/upb-jit-code.s"); - ret = symlink(so_filename, "/tmp/upb-jit-code.so"); - UPB_UNUSED(ret); // We don't care if this fails. - - jc->group->dl = dlopen(so_filename, RTLD_LAZY); - free(so_filename); - if (!jc->group->dl) { - fprintf(stderr, "Couldn't dlopen(): %s\n", dlerror()); - abort(); - } - - munmap(jc->group->jit_code, jc->group->jit_size); - jc->group->jit_code = dlsym(jc->group->dl, "X.enterjit"); - if (!jc->group->jit_code) { - fprintf(stderr, "Couldn't find enterjit sym\n"); - abort(); - } - - upb_inttable_uninit(&mclabels); -} - -#endif - -void upb_pbdecoder_jit(mgroup *group) { - jitcompiler *jc; - char *jit_code; - int dasm_status; - - group->debug_info = NULL; - group->dl = NULL; - - UPB_ASSERT(group->bytecode); - jc = newjitcompiler(group); - emit_static_asm(jc); - jitbytecode(jc); - - dasm_status = dasm_link(jc, &jc->group->jit_size); - if (dasm_status != DASM_S_OK) { - fprintf(stderr, "DynASM error; returned status: 0x%08x\n", dasm_status); - abort(); - } - - jit_code = mmap(NULL, jc->group->jit_size, PROT_READ | PROT_WRITE, - MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); - dasm_encode(jc, jit_code); - mprotect(jit_code, jc->group->jit_size, PROT_EXEC | PROT_READ); - jc->group->jit_code = (upb_string_handlerfunc *)jit_code; - -#ifdef UPB_JIT_LOAD_SO - load_so(jc); -#endif - - patchdispatch(jc); - - freejitcompiler(jc); - - /* Now the bytecode is no longer needed. */ - free(group->bytecode); - group->bytecode = NULL; -} - -void upb_pbdecoder_freejit(mgroup *group) { - if (!group->jit_code) return; - if (group->dl) { -#ifdef UPB_JIT_LOAD_SO - dlclose(group->dl); -#endif - } else { - munmap((void*)group->jit_code, group->jit_size); - } - free(group->debug_info); -} |