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remove workaround for Linux kernel MPK fork bug

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This commit is contained in:
Daniel Micay 2020-04-24 02:51:10 -04:00
parent c75dcb9d9c
commit 19365c25d6
2 changed files with 7 additions and 20 deletions
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19
h_malloc.c
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@ -80,7 +80,6 @@ static union {
struct region_metadata *regions[2];
#ifdef USE_PKEY
int metadata_pkey;
bool pkey_state_preserved_on_fork;
#endif
};
char padding[PAGE_SIZE];
@ -1023,15 +1022,6 @@ static void full_unlock(void) {
static void post_fork_child(void) {
thread_unseal_metadata();
#ifdef USE_PKEY
if (!ro.pkey_state_preserved_on_fork) {
// disable sealing to work around kernel bug causing fork to lose the pkey setup
memory_protect_rw(&ro, sizeof(ro));
ro.metadata_pkey = -1;
memory_protect_ro(&ro, sizeof(ro));
}
#endif
mutex_init(&ro.region_allocator->lock);
random_state_init(&ro.region_allocator->rng);
for (unsigned arena = 0; arena < N_ARENA; arena++) {
@ -1066,15 +1056,6 @@ COLD static void init_slow_path(void) {
#ifdef USE_PKEY
ro.metadata_pkey = pkey_alloc(0, 0);
// pkey state is not preserved on fork before Linux 5.0 unless the patch was backported
struct utsname uts;
if (uname(&uts) == 0) {
unsigned long version = strtoul(uts.release, NULL, 10);
if (version >= 5) {
ro.pkey_state_preserved_on_fork = true;
}
}
#endif
if (sysconf(_SC_PAGESIZE) != PAGE_SIZE) {