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Revert "Add debug logging for memtag level"

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This reverts commit b3f3e86878.

Reason for revert: This created spam in tombstones.

This is a cherry-pick of dd44378da7a6912ce3b7ae171c70cc4eda53f2d

Bug: 280493417

Merged-In: Ia7b8285a6abd6f89d49859a981be1c9cfa104f81
Change-Id: Ia7b8285a6abd6f89d49859a981be1c9cfa104f81
This commit is contained in:
Florian Mayer 2023-05-17 20:59:14 +00:00
parent 9e2120bde3
commit 9908b1e3c8
4 changed files with 19 additions and 37 deletions
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4
libc/bionic/gwp_asan_wrappers.cpp
View file

@ -307,10 +307,8 @@ bool GetGwpAsanOptionImpl(char* value_out,
sysprop_names[3] = persist_default_sysprop;
}
// TODO(mitchp): Log overrides using this.
const char* source;
return get_config_from_env_or_sysprops(env_var, sysprop_names, arraysize(sysprop_names),
value_out, PROP_VALUE_MAX, &source);
value_out, PROP_VALUE_MAX);
}
bool GetGwpAsanIntegerOption(unsigned long long* result,

33
libc/bionic/libc_init_static.cpp
View file

@ -217,13 +217,16 @@ static unsigned __get_memtag_note(const ElfW(Phdr)* phdr_start, size_t phdr_ct,
// Returns true if there's an environment setting (either sysprop or env var)
// that should overwrite the ELF note, and places the equivalent heap tagging
// level into *level.
static bool get_environment_memtag_setting(const char* basename, HeapTaggingLevel* level) {
static bool get_environment_memtag_setting(HeapTaggingLevel* level) {
static const char kMemtagPrognameSyspropPrefix[] = "arm64.memtag.process.";
static const char kMemtagGlobalSysprop[] = "persist.arm64.memtag.default";
static const char kMemtagOverrideSyspropPrefix[] =
"persist.device_config.memory_safety_native.mode_override.process.";
if (basename == nullptr) return false;
const char* progname = __libc_shared_globals()->init_progname;
if (progname == nullptr) return false;
const char* basename = __gnu_basename(progname);
char options_str[PROP_VALUE_MAX];
char sysprop_name[512];
@ -234,9 +237,8 @@ static bool get_environment_memtag_setting(const char* basename, HeapTaggingLeve
kMemtagOverrideSyspropPrefix, basename);
const char* sys_prop_names[] = {sysprop_name, remote_sysprop_name, kMemtagGlobalSysprop};
const char* source = nullptr;
if (!get_config_from_env_or_sysprops("MEMTAG_OPTIONS", sys_prop_names, arraysize(sys_prop_names),
options_str, sizeof(options_str), &source)) {
options_str, sizeof(options_str))) {
return false;
}
@ -247,20 +249,14 @@ static bool get_environment_memtag_setting(const char* basename, HeapTaggingLeve
} else if (strcmp("off", options_str) == 0) {
*level = M_HEAP_TAGGING_LEVEL_TBI;
} else {
async_safe_format_log(ANDROID_LOG_ERROR, "libc",
"%s: unrecognized memtag level in %s: \"%s\" (options are \"sync\", "
"\"async\", or \"off\").",
basename, source, options_str);
async_safe_format_log(
ANDROID_LOG_ERROR, "libc",
"unrecognized memtag level: \"%s\" (options are \"sync\", \"async\", or \"off\").",
options_str);
return false;
}
async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "%s: chose memtag level \"%s\" from %s.",
basename, options_str, source);
return true;
}
static void log_elf_memtag_level(const char* basename, const char* level) {
async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "%s: chose memtag level \"%s\" from ELF note",
basename ?: "<unknown>", level);
return true;
}
// Returns the initial heap tagging level. Note: This function will never return
@ -268,14 +264,12 @@ static void log_elf_memtag_level(const char* basename, const char* level) {
// M_HEAP_TAGGING_LEVEL_TBI.
static HeapTaggingLevel __get_heap_tagging_level(const void* phdr_start, size_t phdr_ct,
uintptr_t load_bias, bool* stack) {
const char* progname = __libc_shared_globals()->init_progname;
const char* basename = progname ? __gnu_basename(progname) : nullptr;
unsigned note_val =
__get_memtag_note(reinterpret_cast<const ElfW(Phdr)*>(phdr_start), phdr_ct, load_bias);
*stack = note_val & NT_MEMTAG_STACK;
HeapTaggingLevel level;
if (get_environment_memtag_setting(basename, &level)) return level;
if (get_environment_memtag_setting(&level)) return level;
// Note, previously (in Android 12), any value outside of bits [0..3] resulted
// in a check-fail. In order to be permissive of further extensions, we
@ -290,17 +284,14 @@ static HeapTaggingLevel __get_heap_tagging_level(const void* phdr_start, size_t
// by anyone, but we note it (heh) here for posterity, in case the zero
// level becomes meaningful, and binaries with this note can be executed
// on Android 12 devices.
log_elf_memtag_level(basename, "off");
return M_HEAP_TAGGING_LEVEL_TBI;
case NT_MEMTAG_LEVEL_ASYNC:
log_elf_memtag_level(basename, "async");
return M_HEAP_TAGGING_LEVEL_ASYNC;
case NT_MEMTAG_LEVEL_SYNC:
default:
// We allow future extensions to specify mode 3 (currently unused), with
// the idea that it might be used for ASYMM mode or something else. On
// this version of Android, it falls back to SYNC mode.
log_elf_memtag_level(basename, "sync");
return M_HEAP_TAGGING_LEVEL_SYNC;
}
}

10
libc/bionic/sysprop_helpers.cpp
View file

@ -57,22 +57,18 @@ static bool get_property_value(const char* property_name, char* dest, size_t des
}
bool get_config_from_env_or_sysprops(const char* env_var_name, const char* const* sys_prop_names,
size_t sys_prop_names_size, char* options, size_t options_size,
const char** chosen_source) {
size_t sys_prop_names_size, char* options,
size_t options_size) {
const char* env = getenv(env_var_name);
if (env && *env != '\0') {
strncpy(options, env, options_size);
options[options_size - 1] = '\0'; // Ensure null-termination.
*chosen_source = env_var_name;
return true;
}
for (size_t i = 0; i < sys_prop_names_size; ++i) {
if (sys_prop_names[i] == nullptr) continue;
if (get_property_value(sys_prop_names[i], options, options_size)) {
*chosen_source = sys_prop_names[i];
return true;
}
if (get_property_value(sys_prop_names[i], options, options_size)) return true;
}
return false;
}

9
libc/bionic/sysprop_helpers.h
View file

@ -36,13 +36,10 @@
// 2. System properties, in the order they're specified in sys_prop_names.
// If neither of these options are specified (or they're both an empty string),
// this function returns false. Otherwise, it returns true, and the presiding
// options string is written to the `options` buffer of size `size`. It will
// store a pointer to either env_var_name, or into the relevant entry of
// sys_prop_names into choicen_source, indiciating which value was used. If
// this function returns true, `options` is guaranteed to be null-terminated.
// options string is written to the `options` buffer of size `size`. If this
// function returns true, `options` is guaranteed to be null-terminated.
// `options_size` should be at least PROP_VALUE_MAX.
__LIBC_HIDDEN__ bool get_config_from_env_or_sysprops(const char* env_var_name,
const char* const* sys_prop_names,
size_t sys_prop_names_size, char* options,
size_t options_size,
const char** chosen_source);
size_t options_size);