Date: Sun, 14 Jun 2015 07:47:19 +0000 (UTC) From: Jeremie Le Hen <jlh@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r284377 - head/lib/libc/sys Message-ID: <201506140747.t5E7lJvh029406@svn.freebsd.org>
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Author: jlh Date: Sun Jun 14 07:47:18 2015 New Revision: 284377 URL: https://svnweb.freebsd.org/changeset/base/284377 Log: 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 MFC after: 1 week Modified: head/lib/libc/sys/stack_protector.c Modified: head/lib/libc/sys/stack_protector.c ============================================================================== --- head/lib/libc/sys/stack_protector.c Sun Jun 14 05:23:39 2015 (r284376) +++ head/lib/libc/sys/stack_protector.c Sun Jun 14 07:47:18 2015 (r284377) @@ -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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