Date: Tue, 22 Sep 2015 10:48:29 +0000 (UTC) From: Jeremie Le Hen <jlh@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r288105 - stable/10/lib/libc/sys Message-ID: <201509221048.t8MAmTXb082096@repo.freebsd.org>
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Author: jlh Date: Tue Sep 22 10:48:28 2015 New Revision: 288105 URL: https://svnweb.freebsd.org/changeset/base/288105 Log: Long overdue MFC r284377: NetBSD commit log: Use a constant array for the MIB. Newer LLVM decided that mib[] warranted stack protections, with the obvious crash after the setup was done. As a positive side effect, code size shrinks a bit. I'm not sure why this hasn't bitten us yes, but it is certainly possible and there are no real drawbacks to this change anyway. Submitted by: pfg Obtained from: NetBSD Modified: stable/10/lib/libc/sys/stack_protector.c Directory Properties: stable/10/ (props changed) Modified: stable/10/lib/libc/sys/stack_protector.c ============================================================================== --- stable/10/lib/libc/sys/stack_protector.c Tue Sep 22 10:45:50 2015 (r288104) +++ stable/10/lib/libc/sys/stack_protector.c Tue Sep 22 10:48:28 2015 (r288105) @@ -41,8 +41,8 @@ __FBSDID("$FreeBSD$"); #include <unistd.h> #include "libc_private.h" -extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, - void *newp, size_t newlen); +extern int __sysctl(const int *name, u_int namelen, void *oldp, + size_t *oldlenp, void *newp, size_t newlen); long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; static void __guard_setup(void) __attribute__((__constructor__, __used__)); @@ -54,7 +54,7 @@ void __chk_fail(void); static void __guard_setup(void) { - int mib[2]; + static const int mib[2] = { CTL_KERN, KERN_ARND }; size_t len; int error; @@ -65,12 +65,9 @@ __guard_setup(void) if (error == 0 && __stack_chk_guard[0] != 0) return; - mib[0] = CTL_KERN; - mib[1] = KERN_ARND; - len = sizeof(__stack_chk_guard); - if (__sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || - len != sizeof(__stack_chk_guard)) { + if (__sysctl(mib, nitems(mib), __stack_chk_guard, &len, NULL, 0) == + -1 || len != sizeof(__stack_chk_guard)) { /* If sysctl was unsuccessful, use the "terminator canary". */ ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; ((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
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