Author: markj Date: Fri May 8 14:38:48 2020 New Revision: 360812 URL: https://svnweb.freebsd.org/changeset/base/360812
Log: Reinitialize thread0's stack base after enabling XSAVE. Otherwise the initial call to set_top_of_stack(), which occurs before fpuinit() sets the correct value for cpu_max_ext_state_size, leaves the stack base at an incorrect location. Then, when the full area is zeroed, we end up erroneously zeroing part of the following page. Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D24754 Modified: head/sys/amd64/amd64/machdep.c Modified: head/sys/amd64/amd64/machdep.c ============================================================================== --- head/sys/amd64/amd64/machdep.c Fri May 8 14:13:30 2020 (r360811) +++ head/sys/amd64/amd64/machdep.c Fri May 8 14:38:48 2020 (r360812) @@ -1857,7 +1857,7 @@ hammer_time(u_int64_t modulep, u_int64_t physfree) setidt(IDT_IO_INTS + 15, IDTVEC(spuriousint), SDT_SYSIGT, SEL_KPL, 0); #endif #else -#error "have you forgotten the isa device?"; +#error "have you forgotten the isa device?" #endif if (late_console) @@ -1867,12 +1867,13 @@ hammer_time(u_int64_t modulep, u_int64_t physfree) fpuinit(); /* - * Set up thread0 pcb save area after fpuinit calculated fpu save - * area size. Zero out the extended state header in fpu save - * area. + * Reinitialize thread0's stack base now that the xsave area size is + * known. Set up thread0's pcb save area after fpuinit calculated fpu + * save area size. Zero out the extended state header in fpu save area. */ + set_top_of_stack_td(&thread0); thread0.td_pcb->pcb_save = get_pcb_user_save_td(&thread0); - bzero(get_pcb_user_save_td(&thread0), cpu_max_ext_state_size); + bzero(thread0.td_pcb->pcb_save, cpu_max_ext_state_size); if (use_xsave) { xhdr = (struct xstate_hdr *)(get_pcb_user_save_td(&thread0) + 1); @@ -1882,7 +1883,7 @@ hammer_time(u_int64_t modulep, u_int64_t physfree) rsp0 = thread0.td_md.md_stack_base; /* Ensure the stack is aligned to 16 bytes */ rsp0 &= ~0xFul; - __pcpu[0].pc_common_tss.tss_rsp0 = rsp0; + PCPU_PTR(common_tss)->tss_rsp0 = rsp0; amd64_bsp_pcpu_init2(rsp0); /* transfer to user mode */ _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
