diff options
| author | Elliott Hughes <enh@google.com> | 2016-10-11 12:58:40 -0700 |
|---|---|---|
| committer | Elliott Hughes <enh@google.com> | 2016-10-11 13:07:44 -0700 |
| commit | da01fa620ccce26ae22ebcb51a239ec68ea7b32c (patch) | |
| tree | 1e7a9ac66d9db92f022e282f44eb8105c7eb667e /libc/upstream-openbsd/android/include/arc4random.h | |
| parent | 0e6aa81999c89af2c2e6b0fef1ab21eb4da09892 (diff) | |
Allocate all arc4random data on the same page.
Saves one dirty page per process.
Test: bionic unit tests, reboot, manual check of /proc/*/maps
Change-Id: Ibbcafa955d60e43f4cb735fa484c6868aa357cd5
Diffstat (limited to 'libc/upstream-openbsd/android/include/arc4random.h')
| -rw-r--r-- | libc/upstream-openbsd/android/include/arc4random.h | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/libc/upstream-openbsd/android/include/arc4random.h b/libc/upstream-openbsd/android/include/arc4random.h index 8d965e0f9..0d70c815d 100644 --- a/libc/upstream-openbsd/android/include/arc4random.h +++ b/libc/upstream-openbsd/android/include/arc4random.h @@ -28,6 +28,7 @@ #include <signal.h> #include "private/bionic_prctl.h" +#include "private/libc_logging.h" // Android gets these from "thread_private.h". #include "thread_private.h" @@ -46,7 +47,7 @@ extern int __register_atfork(void (*)(void), void(*)(void), void (*)(void), void static inline void _getentropy_fail(void) { - raise(SIGKILL); + __libc_fatal("getentropy failed"); } volatile sig_atomic_t _rs_forked; @@ -68,21 +69,21 @@ _rs_forkdetect(void) static inline int _rs_allocate(struct _rs **rsp, struct _rsx **rsxp) { - if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE, + // OpenBSD's arc4random_linux.h allocates two separate mappings, but for + // themselves they just allocate both structs into one mapping like this. + struct { + struct _rs rs; + struct _rsx rsx; + } *p; + + if ((p = mmap(NULL, sizeof(*p), PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) return (-1); - prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, *rsp, sizeof(**rsp), - "arc4random _rs structure"); + prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, p, sizeof(*p), "arc4random data"); - if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE, - MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) { - munmap(*rsxp, sizeof(**rsxp)); - return (-1); - } - - prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, *rsxp, sizeof(**rsxp), - "arc4random _rsx structure"); + *rsp = &p->rs; + *rsxp = &p->rsx; return (0); } |