From c566331351e10a5525edd4e523bda0d160768d14 Mon Sep 17 00:00:00 2001 From: jhb Date: Fri, 23 Dec 2016 19:28:15 +0000 Subject: MFC 308820,308821: Fixes for fatal page faults on x86. 308820: Report page faults due to reserved bits in PTEs as a separate fault type. Rather than reporting a page fault due to a bad PTE as a protection violation with the "rsv" flag, treat these faults as a separate type of fault altogether. 308821: MFamd64: Various fatal page fault fixes. - If a page fault is triggered due to reserved bits in a PTE, treat it as a fatal fault and panic. - If PG_NX is in use, report whether a fatal page fault is due to an instruction fetch or a data access. - If a fatal page fault is due to reserved bits in a PTE, report that as the page fault type rather than a protection violation. --- sys/i386/i386/trap.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'sys/i386') diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c index 3cf0c5a..2ab8d1b 100644 --- a/sys/i386/i386/trap.c +++ b/sys/i386/i386/trap.c @@ -857,6 +857,14 @@ trap_pfault(frame, usermode, eva) } /* + * If the trap was caused by errant bits in the PTE then panic. + */ + if (frame->tf_err & PGEX_RSV) { + trap_fatal(frame, eva); + return (-1); + } + + /* * PGEX_I is defined only if the execute disable bit capability is * supported and enabled. */ @@ -926,9 +934,15 @@ trap_fatal(frame, eva) #endif if (type == T_PAGEFLT) { printf("fault virtual address = 0x%x\n", eva); - printf("fault code = %s %s, %s\n", + printf("fault code = %s %s%s, %s\n", code & PGEX_U ? "user" : "supervisor", code & PGEX_W ? "write" : "read", +#if defined(PAE) || defined(PAE_TABLES) + pg_nx != 0 ? + (code & PGEX_I ? " instruction" : " data") : +#endif + "", + code & PGEX_RSV ? "reserved bits in PTE" : code & PGEX_P ? "protection violation" : "page not present"); } printf("instruction pointer = 0x%x:0x%x\n", -- cgit v1.1