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authorSverker Eriksson <[email protected]>2016-11-23 15:55:43 +0100
committerSverker Eriksson <[email protected]>2016-11-23 15:55:43 +0100
commitec776506eac5342da3d45829fb67b669081f6439 (patch)
tree7481f63ae5de72b035eff4c0a7cb92defe383dd3 /erts/emulator/beam/erl_nif.c
parent160a28a0912cf87e971ddcbfdb6f76d64581fe44 (diff)
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erts: Secure abi backward compat for tracer nifs
and simplify the code by handling the compatibility stuff at loading by creating modern struct copies in create_lib().
Diffstat (limited to 'erts/emulator/beam/erl_nif.c')
-rw-r--r--erts/emulator/beam/erl_nif.c128
1 files changed, 70 insertions, 58 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 9872a3ab81..9fec9b4939 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -71,10 +71,12 @@
struct erl_module_nif {
void* priv_data;
void* handle; /* "dlopen" */
- struct enif_entry_t* entry;
+ struct enif_entry_t entry;
erts_refc_t rt_cnt; /* number of resource types */
erts_refc_t rt_dtor_cnt; /* number of resource types with destructors */
Module* mod; /* Can be NULL if orphan with dtor-resources left */
+
+ ErlNifFunc _funcs_copy_[1]; /* only used for old libs */
};
#ifdef DEBUG
@@ -1958,10 +1960,10 @@ static void close_lib(struct erl_module_nif* lib)
ASSERT(lib->handle != NULL);
ASSERT(erts_refc_read(&lib->rt_dtor_cnt,0) == 0);
- if (lib->entry != NULL && lib->entry->unload != NULL) {
+ if (lib->entry.unload != NULL) {
struct enif_msg_environment_t msg_env;
pre_nif_noproc(&msg_env, lib, NULL);
- lib->entry->unload(&msg_env.env, lib->priv_data);
+ lib->entry.unload(&msg_env.env, lib->priv_data);
post_nif_noproc(&msg_env);
}
if (!erts_is_static_nif(lib->handle))
@@ -3115,33 +3117,52 @@ static Eterm load_nif_error(Process* p, const char* atom, const char* format, ..
return ret;
}
+#define AT_LEAST_VERSION(E,MAJ,MIN) \
+ (((E)->major * 0x100 + (E)->minor) >= ((MAJ) * 0x100 + (MIN)))
+
/*
- * The function below is for looping through ErlNifFunc arrays, helping
- * provide backwards compatibility across the version 2.7 change that added
- * the "flags" field to ErlNifFunc.
+ * Allocate erl_module_nif and make a _modern_ copy of the lib entry.
*/
-static ErlNifFunc* next_func(ErlNifEntry* entry, int* incrp, ErlNifFunc* func)
+static struct erl_module_nif* create_lib(const ErlNifEntry* src)
{
- ASSERT(incrp);
- if (!*incrp) {
- if (entry->major > 2 || (entry->major == 2 && entry->minor >= 7))
- *incrp = sizeof(ErlNifFunc);
- else {
- /*
- * ErlNifFuncV1 below is what ErlNifFunc was before the
- * addition of the flags field for 2.7, and is needed to handle
- * backward compatibility.
- */
- typedef struct {
- const char* name;
- unsigned arity;
- ERL_NIF_TERM (*fptr)(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
- }ErlNifFuncV1;
- *incrp = sizeof(ErlNifFuncV1);
- }
+ struct erl_module_nif* lib;
+ ErlNifEntry* dst;
+ Uint bytes = offsetof(struct erl_module_nif, _funcs_copy_);
+
+ if (!AT_LEAST_VERSION(src, 2, 7))
+ bytes += src->num_of_funcs * sizeof(ErlNifFunc);
+
+ lib = erts_alloc(ERTS_ALC_T_NIF, bytes);
+ dst = &lib->entry;
+
+ sys_memcpy(dst, src, offsetof(ErlNifEntry, vm_variant));
+
+ if (AT_LEAST_VERSION(src, 2, 1)) {
+ dst->vm_variant = src->vm_variant;
+ } else {
+ dst->vm_variant = "beam.vanilla";
}
- return (ErlNifFunc*) ((char*)func + *incrp);
-}
+ if (AT_LEAST_VERSION(src, 2, 7)) {
+ dst->options = src->options;
+ } else {
+ /*
+ * Make a modern copy of the ErlNifFunc array
+ */
+ struct ErlNifFunc_V1 {
+ const char* name;
+ unsigned arity;
+ ERL_NIF_TERM (*fptr)(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
+ }*src_funcs = (struct ErlNifFunc_V1*) src->funcs;
+ int i;
+ for (i = 0; i < src->num_of_funcs; ++i) {
+ sys_memcpy(&lib->_funcs_copy_[i], &src_funcs[i], sizeof(*src_funcs));
+ lib->_funcs_copy_[i].flags = 0;
+ }
+ dst->funcs = lib->_funcs_copy_;
+ dst->options = 0;
+ }
+ return lib;
+};
BIF_RETTYPE load_nif_2(BIF_ALIST_2)
@@ -3261,7 +3282,7 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
ret = load_nif_error(BIF_P, bad_lib, "Library version (%d.%d) not compatible (with %d.%d).",
entry->major, entry->minor, ERL_NIF_MAJOR_VERSION, ERL_NIF_MINOR_VERSION);
}
- else if (entry->minor >= 1
+ else if (AT_LEAST_VERSION(entry, 2, 1)
&& sys_strcmp(entry->vm_variant, ERL_NIF_VM_VARIANT) != 0) {
ret = load_nif_error(BIF_P, bad_lib, "Library (%s) not compiled for "
"this vm variant (%s).",
@@ -3272,20 +3293,25 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
" match calling module '%T'", entry->name, mod_atom);
}
else {
- /*erts_fprintf(stderr, "Found module %T\r\n", mod_atom);*/
+ lib = create_lib(entry);
+ entry = &lib->entry; /* Use a guaranteed modern lib entry from now on */
+
+ lib->handle = handle;
+ erts_refc_init(&lib->rt_cnt, 0);
+ erts_refc_init(&lib->rt_dtor_cnt, 0);
+ ASSERT(opened_rt_list == NULL);
+ lib->mod = module_p;
- int maybe_dirty_nifs = ((entry->major > 2 || (entry->major == 2 && entry->minor >= 7))
- && (entry->options & ERL_NIF_DIRTY_NIF_OPTION));
- int incr = 0;
- ErlNifFunc* f = entry->funcs;
- for (i=0; i < entry->num_of_funcs && ret==am_ok; i++) {
+ for (i=0; i < entry->num_of_funcs && ret==am_ok; i++) {
ErtsCodeInfo** ci_pp;
+ ErlNifFunc* f = &entry->funcs[i];
+
if (!erts_atom_get(f->name, sys_strlen(f->name), &f_atom, ERTS_ATOM_ENC_LATIN1)
|| (ci_pp = get_func_pp(this_mi->code_hdr, f_atom, f->arity))==NULL) {
ret = load_nif_error(BIF_P,bad_lib,"Function not found %T:%s/%u",
mod_atom, f->name, f->arity);
}
- else if (maybe_dirty_nifs && f->flags) {
+ else if (f->flags) {
/*
* If the flags field is non-zero and this emulator was
* built with dirty scheduler support, check that the flags
@@ -3314,7 +3340,6 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
}
/*erts_fprintf(stderr, "Found NIF %T:%s/%u\r\n",
mod_atom, f->name, f->arity);*/
- f = next_func(entry, &incr, f);
}
}
@@ -3325,14 +3350,6 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
/* Call load or upgrade:
*/
-
- lib = erts_alloc(ERTS_ALC_T_NIF, sizeof(struct erl_module_nif));
- lib->handle = handle;
- lib->entry = entry;
- erts_refc_init(&lib->rt_cnt, 0);
- erts_refc_init(&lib->rt_dtor_cnt, 0);
- ASSERT(opened_rt_list == NULL);
- lib->mod = module_p;
env.mod_nif = lib;
lib->priv_data = NULL;
@@ -3349,8 +3366,6 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
prev_mi->nif->priv_data = prev_old_data;
ret = load_nif_error(BIF_P, upgrade, "Library upgrade-call unsuccessful (%d).", veto);
}
- else
- commit_opened_resource_types(lib);
}
else if (entry->load != NULL) { /********* Initial load ***********/
erts_pre_nif(&env, BIF_P, lib, NULL);
@@ -3359,22 +3374,21 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
if (veto) {
ret = load_nif_error(BIF_P, "load", "Library load-call unsuccessful (%d).", veto);
}
- else
- commit_opened_resource_types(lib);
}
if (ret == am_ok) {
+ commit_opened_resource_types(lib);
+
/*
** Everything ok, patch the beam code with op_call_nif
*/
- int incr = 0;
- ErlNifFunc* f = entry->funcs;
-
this_mi->nif = lib;
for (i=0; i < entry->num_of_funcs; i++)
{
+ ErlNifFunc* f = &entry->funcs[i];
ErtsCodeInfo* ci;
BeamInstr *code_ptr;
+
erts_atom_get(f->name, sys_strlen(f->name), &f_atom, ERTS_ATOM_ENC_LATIN1);
ci = *get_func_pp(this_mi->code_hdr, f_atom, f->arity);
code_ptr = erts_codeinfo_to_code(ci);
@@ -3389,8 +3403,7 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
g->orig_instr = (BeamInstr) BeamOp(op_call_nif);
}
#ifdef ERTS_DIRTY_SCHEDULERS
- if ((entry->major > 2 || (entry->major == 2 && entry->minor >= 7))
- && (entry->options & ERL_NIF_DIRTY_NIF_OPTION) && f->flags) {
+ if (f->flags) {
code_ptr[3] = (BeamInstr) f->fptr;
code_ptr[1] = (f->flags == ERL_NIF_DIRTY_JOB_IO_BOUND) ?
(BeamInstr) schedule_dirty_io_nif :
@@ -3400,7 +3413,6 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
#endif
code_ptr[1] = (BeamInstr) f->fptr;
code_ptr[2] = (BeamInstr) lib;
- f = next_func(entry, &incr, f);
}
}
else {
@@ -3484,8 +3496,8 @@ void erl_nif_init()
int erts_nif_get_funcs(struct erl_module_nif* mod,
ErlNifFunc **funcs)
{
- *funcs = mod->entry->funcs;
- return mod->entry->num_of_funcs;
+ *funcs = mod->entry.funcs;
+ return mod->entry.num_of_funcs;
}
Eterm erts_nif_call_function(Process *p, Process *tracee,
@@ -3496,10 +3508,10 @@ Eterm erts_nif_call_function(Process *p, Process *tracee,
#ifdef DEBUG
/* Verify that function is part of this module */
int i;
- for (i = 0; i < mod->entry->num_of_funcs; i++)
- if (fun == &(mod->entry->funcs[i]))
+ for (i = 0; i < mod->entry.num_of_funcs; i++)
+ if (fun == &(mod->entry.funcs[i]))
break;
- ASSERT(i < mod->entry->num_of_funcs);
+ ASSERT(i < mod->entry.num_of_funcs);
if (p)
ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(p) & ERTS_PROC_LOCK_MAIN
|| erts_smp_thr_progress_is_blocking());