Date: Tue, 20 Mar 2018 20:20:50 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r331258 - in head/sys: amd64/amd64 amd64/include x86/include x86/x86 Message-ID: <201803202020.w2KKKo7Y033740@repo.freebsd.org>
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Author: kib Date: Tue Mar 20 20:20:49 2018 New Revision: 331258 URL: https://svnweb.freebsd.org/changeset/base/331258 Log: Move the CR0.WP manipulation KPI to x86. This should allow to avoid some #ifdefs in the common x86/ code. Requested by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/sys/amd64/amd64/machdep.c head/sys/amd64/include/md_var.h head/sys/x86/include/x86_var.h head/sys/x86/x86/cpu_machdep.c Modified: head/sys/amd64/amd64/machdep.c ============================================================================== --- head/sys/amd64/amd64/machdep.c Tue Mar 20 20:05:11 2018 (r331257) +++ head/sys/amd64/amd64/machdep.c Tue Mar 20 20:20:49 2018 (r331258) @@ -2597,31 +2597,6 @@ clear_pcb_flags(struct pcb *pcb, const u_int flags) : "cc", "memory"); } -/* - * Enable and restore kernel text write permissions. - * Callers must ensure that disable_wp()/restore_wp() are executed - * without rescheduling on the same core. - */ -bool -disable_wp(void) -{ - u_int cr0; - - cr0 = rcr0(); - if ((cr0 & CR0_WP) == 0) - return (false); - load_cr0(cr0 & ~CR0_WP); - return (true); -} - -void -restore_wp(bool old_wp) -{ - - if (old_wp) - load_cr0(rcr0() | CR0_WP); -} - #ifdef KDB /* Modified: head/sys/amd64/include/md_var.h ============================================================================== --- head/sys/amd64/include/md_var.h Tue Mar 20 20:05:11 2018 (r331257) +++ head/sys/amd64/include/md_var.h Tue Mar 20 20:20:49 2018 (r331258) @@ -53,8 +53,6 @@ void amd64_conf_fast_syscall(void); void amd64_db_resume_dbreg(void); void amd64_lower_shared_page(struct sysentvec *); void amd64_syscall(struct thread *td, int traced); -bool disable_wp(void); -void restore_wp(bool old_wp); void doreti_iret(void) __asm(__STRING(doreti_iret)); void doreti_iret_fault(void) __asm(__STRING(doreti_iret_fault)); void ld_ds(void) __asm(__STRING(ld_ds)); Modified: head/sys/x86/include/x86_var.h ============================================================================== --- head/sys/x86/include/x86_var.h Tue Mar 20 20:05:11 2018 (r331257) +++ head/sys/x86/include/x86_var.h Tue Mar 20 20:20:49 2018 (r331258) @@ -119,6 +119,8 @@ void busdma_swi(void); bool cpu_mwait_usable(void); void cpu_probe_amdc1e(void); void cpu_setregs(void); +bool disable_wp(void); +void restore_wp(bool old_wp); void dump_add_page(vm_paddr_t); void dump_drop_page(vm_paddr_t); void finishidentcpu(void); Modified: head/sys/x86/x86/cpu_machdep.c ============================================================================== --- head/sys/x86/x86/cpu_machdep.c Tue Mar 20 20:05:11 2018 (r331257) +++ head/sys/x86/x86/cpu_machdep.c Tue Mar 20 20:20:49 2018 (r331258) @@ -621,3 +621,29 @@ hw_ibrs_disable_handler(SYSCTL_HANDLER_ARGS) SYSCTL_PROC(_hw, OID_AUTO, ibrs_disable, CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0, hw_ibrs_disable_handler, "I", "Disable Indirect Branch Restricted Speculation"); + +/* + * Enable and restore kernel text write permissions. + * Callers must ensure that disable_wp()/restore_wp() are executed + * without rescheduling on the same core. + */ +bool +disable_wp(void) +{ + u_int cr0; + + cr0 = rcr0(); + if ((cr0 & CR0_WP) == 0) + return (false); + load_cr0(cr0 & ~CR0_WP); + return (true); +} + +void +restore_wp(bool old_wp) +{ + + if (old_wp) + load_cr0(rcr0() | CR0_WP); +} +
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