[lib][trusty] Use position-relative references for KASLR
Use position-relative instead of absolute addresses in trusty_app_img
in preparation for KASLR.
Bug: 80147716
Change-Id: I6c2c189d11eee0e0ca339b06dc2a0be7d088b93c
diff --git a/app/trusty/appobj.S b/app/trusty/appobj.S
index 913067f..d3c7538 100644
--- a/app/trusty/appobj.S
+++ b/app/trusty/appobj.S
@@ -39,7 +39,7 @@
.task.manifest.end:
.section .task.list, "a"
-DATA_PTR .task.manifest.start
-DATA_PTR .task.manifest.end
-DATA_PTR .task.body.start
-DATA_PTR .task.body.end
+DATA_PTR .task.manifest.start - .
+DATA_PTR .task.manifest.end - .
+DATA_PTR .task.body.start - .
+DATA_PTR .task.body.end - .
diff --git a/lib/backtrace/symbolize.c b/lib/backtrace/symbolize.c
index 7c6f644..d365734 100644
--- a/lib/backtrace/symbolize.c
+++ b/lib/backtrace/symbolize.c
@@ -81,7 +81,7 @@
goto out_no_symbol;
}
/* pc must be within the app image */
- struct trusty_app_img* app_img = app->app_img;
+ struct trusty_app_img* app_img = &app->app_img;
if (app_img->img_end <= app_img->img_start) {
goto out_no_symbol;
}
diff --git a/lib/trusty/include/lib/trusty/trusty_app.h b/lib/trusty/include/lib/trusty/trusty_app.h
index 3122112..5733b5a 100644
--- a/lib/trusty/include/lib/trusty/trusty_app.h
+++ b/lib/trusty/include/lib/trusty/trusty_app.h
@@ -152,7 +152,7 @@
vaddr_t end_brk;
vaddr_t load_bias;
struct trusty_app_props props;
- struct trusty_app_img* app_img;
+ struct trusty_app_img app_img;
struct trusty_thread* thread;
/* app local storage */
void** als;
diff --git a/lib/trusty/trusty_app.c b/lib/trusty/trusty_app.c
index 4b8060a..f0037ef 100644
--- a/lib/trusty/trusty_app.c
+++ b/lib/trusty/trusty_app.c
@@ -102,12 +102,19 @@
static u_int trusty_next_app_id;
static struct list_node trusty_app_list = LIST_INITIAL_VALUE(trusty_app_list);
+struct trusty_builtin_app_img {
+ intptr_t manifest_start;
+ intptr_t manifest_end;
+ intptr_t img_start;
+ intptr_t img_end;
+};
+
/* These symbols are linker defined and are declared as unsized arrays to
* prevent compiler(clang) optimizations that break when the list is empty and
* the symbols alias
*/
-extern struct trusty_app_img __trusty_app_list_start[];
-extern struct trusty_app_img __trusty_app_list_end[];
+extern struct trusty_builtin_app_img __trusty_app_list_start[];
+extern struct trusty_builtin_app_img __trusty_app_list_end[];
static bool apps_started;
static mutex_t apps_lock = MUTEX_INITIAL_VALUE(apps_lock);
@@ -554,7 +561,7 @@
size_t* size) {
struct trusty_app_img* app_img;
- app_img = trusty_app->app_img;
+ app_img = &trusty_app->app_img;
if (!app_img->manifest_start) {
dprintf(CRITICAL, "manifest section header not found\n");
return ERR_NOT_VALID;
@@ -566,9 +573,8 @@
app_img->manifest_end - app_img->manifest_start,
(void*)app_img->manifest_end);
- *size = trusty_app->app_img->manifest_end -
- trusty_app->app_img->manifest_start;
- *manifest_data = (char*)(trusty_app->app_img->manifest_start);
+ *size = app_img->manifest_end - app_img->manifest_start;
+ *manifest_data = (char*)app_img->manifest_start;
return NO_ERROR;
}
@@ -924,8 +930,8 @@
static bool elf_vaddr_mapped(struct trusty_app* trusty_app,
size_t vaddr,
ssize_t offset) {
- ELF_EHDR* elf_hdr = (ELF_EHDR*)trusty_app->app_img->img_start;
- void* trusty_app_image = (void*)trusty_app->app_img->img_start;
+ ELF_EHDR* elf_hdr = (ELF_EHDR*)trusty_app->app_img.img_start;
+ void* trusty_app_image = (void*)trusty_app->app_img.img_start;
ELF_PHDR* prg_hdr = (ELF_PHDR*)(trusty_app_image + elf_hdr->e_phoff);
if (__builtin_add_overflow(vaddr, offset, &vaddr)) {
return false;
@@ -943,17 +949,17 @@
}
static status_t alloc_address_map(struct trusty_app* trusty_app) {
- ELF_EHDR* elf_hdr = (ELF_EHDR*)trusty_app->app_img->img_start;
+ ELF_EHDR* elf_hdr = (ELF_EHDR*)trusty_app->app_img.img_start;
void* trusty_app_image;
ELF_PHDR* prg_hdr;
u_int i;
status_t ret;
- trusty_app_image = (void*)trusty_app->app_img->img_start;
+ trusty_app_image = (void*)trusty_app->app_img.img_start;
prg_hdr = (ELF_PHDR*)(trusty_app_image + elf_hdr->e_phoff);
if (!address_range_within_img(prg_hdr, sizeof(ELF_PHDR) * elf_hdr->e_phnum,
- trusty_app->app_img)) {
+ &trusty_app->app_img)) {
dprintf(CRITICAL, "ELF program headers table out of bounds\n");
return ERR_NOT_VALID;
}
@@ -1037,7 +1043,7 @@
mapping_size = round_up(prg_hdr->p_memsz, PAGE_SIZE);
if (!address_range_within_img((void*)img_kvaddr, prg_hdr->p_filesz,
- trusty_app->app_img)) {
+ &trusty_app->app_img)) {
dprintf(CRITICAL, "ELF Program segment %u out of bounds\n", i);
return ERR_NOT_VALID;
}
@@ -1078,7 +1084,7 @@
mapping_size = round_up(prg_hdr->p_filesz, PAGE_SIZE);
if (!address_range_within_img((void*)img_kvaddr, mapping_size,
- trusty_app->app_img)) {
+ &trusty_app->app_img)) {
dprintf(CRITICAL, "ELF Program segment %u out of bounds\n", i);
return ERR_NOT_VALID;
}
@@ -1247,7 +1253,7 @@
}
trusty_app->app_id = trusty_next_app_id++;
- trusty_app->app_img = app_img;
+ trusty_app->app_img = *app_img;
trusty_app->state = APP_NOT_RUNNING;
trusty_app->flags |= flags;
@@ -1415,7 +1421,7 @@
}
}
- elf_hdr = (ELF_EHDR*)trusty_app->app_img->img_start;
+ elf_hdr = (ELF_EHDR*)trusty_app->app_img.img_start;
vaddr_t entry;
__builtin_add_overflow(elf_hdr->e_entry, trusty_app->load_bias, &entry);
trusty_thread = trusty_thread_create(
@@ -1662,16 +1668,37 @@
return ret;
}
+/**
+ * prel_to_abs_ptr() - Convert a position-relative value to an absolute.
+ * @ptr: Pointer to a pointer-sized position-relative value.
+ * @result: Pointer to the location for the result.
+ *
+ * Return: %true in case of success, %false for overflow.
+ */
+static inline bool prel_to_abs_ptr(const intptr_t* ptr, uintptr_t* result) {
+ return !__builtin_add_overflow((uintptr_t)ptr, *ptr, result);
+}
+
void trusty_app_init(void) {
- struct trusty_app_img* app_img;
+ struct trusty_builtin_app_img* builtin_app_img;
finalize_registration();
app_mgr_init();
- for (app_img = __trusty_app_list_start; app_img != __trusty_app_list_end;
- app_img++) {
- if (trusty_app_create(app_img, NULL, 0) != NO_ERROR)
+ for (builtin_app_img = __trusty_app_list_start;
+ builtin_app_img != __trusty_app_list_end; builtin_app_img++) {
+ struct trusty_app_img app_img;
+ if (!prel_to_abs_ptr(&builtin_app_img->manifest_start,
+ &app_img.manifest_start) ||
+ !prel_to_abs_ptr(&builtin_app_img->manifest_end,
+ &app_img.manifest_end) ||
+ !prel_to_abs_ptr(&builtin_app_img->img_start, &app_img.img_start) ||
+ !prel_to_abs_ptr(&builtin_app_img->img_end, &app_img.img_end)) {
+ panic("Invalid builtin function entry\n");
+ }
+
+ if (trusty_app_create(&app_img, NULL, 0) != NO_ERROR)
panic("Failed to create builtin apps\n");
}
}
