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author | neel <neel@FreeBSD.org> | 2014-05-14 22:24:09 +0000 |
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committer | neel <neel@FreeBSD.org> | 2014-05-14 22:24:09 +0000 |
commit | 5df866f4b184bed9ee5696646c5f344532ca9194 (patch) | |
tree | 398b47711331c96a2e9d3e3eddbe70ee15fcf641 /sys/amd64 | |
parent | 10498d9298eec5778c1af445b70a940b4a61f5b8 (diff) | |
download | FreeBSD-src-5df866f4b184bed9ee5696646c5f344532ca9194.zip FreeBSD-src-5df866f4b184bed9ee5696646c5f344532ca9194.tar.gz |
Increase the TSS limit by one byte. The processor requires an additional byte
with all bits set to 1 beyond the I/O permission bitmap.
Prior to this change accessing I/O ports [0xFFF8-0xFFFF] would trigger a
#GP fault even though the I/O bitmap allowed access to those ports.
For more details see section "I/O Permission Bit Map" in the Intel SDM, Vol 1.
Reviewed by: kib
Diffstat (limited to 'sys/amd64')
-rw-r--r-- | sys/amd64/amd64/machdep.c | 5 | ||||
-rw-r--r-- | sys/amd64/amd64/mp_machdep.c | 2 | ||||
-rw-r--r-- | sys/amd64/amd64/sys_machdep.c | 5 | ||||
-rw-r--r-- | sys/amd64/include/param.h | 6 |
4 files changed, 10 insertions, 8 deletions
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c index cc2b581..14cb137 100644 --- a/sys/amd64/amd64/machdep.c +++ b/sys/amd64/amd64/machdep.c @@ -1147,7 +1147,7 @@ struct soft_segment_descriptor gdt_segs[] = { .ssd_gran = 1 }, /* GPROC0_SEL 9 Proc 0 Tss Descriptor */ { .ssd_base = 0x0, - .ssd_limit = sizeof(struct amd64tss) + IOPAGES * PAGE_SIZE - 1, + .ssd_limit = sizeof(struct amd64tss) + IOPERM_BITMAP_SIZE - 1, .ssd_type = SDT_SYSTSS, .ssd_dpl = SEL_KPL, .ssd_p = 1, @@ -2003,8 +2003,7 @@ hammer_time(u_int64_t modulep, u_int64_t physfree) common_tss[0].tss_ist2 = (long) np; /* Set the IO permission bitmap (empty due to tss seg limit) */ - common_tss[0].tss_iobase = sizeof(struct amd64tss) + - IOPAGES * PAGE_SIZE; + common_tss[0].tss_iobase = sizeof(struct amd64tss) + IOPERM_BITMAP_SIZE; gsel_tss = GSEL(GPROC0_SEL, SEL_KPL); ltr(gsel_tss); diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c index 484fc06..6e59645 100644 --- a/sys/amd64/amd64/mp_machdep.c +++ b/sys/amd64/amd64/mp_machdep.c @@ -637,7 +637,7 @@ init_secondary(void) common_tss[cpu] = common_tss[0]; common_tss[cpu].tss_rsp0 = 0; /* not used until after switch */ common_tss[cpu].tss_iobase = sizeof(struct amd64tss) + - IOPAGES * PAGE_SIZE; + IOPERM_BITMAP_SIZE; common_tss[cpu].tss_ist1 = (long)&doublefault_stack[PAGE_SIZE]; /* The NMI stack runs on IST2. */ diff --git a/sys/amd64/amd64/sys_machdep.c b/sys/amd64/amd64/sys_machdep.c index 26f38a2..1d9bd4c 100644 --- a/sys/amd64/amd64/sys_machdep.c +++ b/sys/amd64/amd64/sys_machdep.c @@ -338,7 +338,6 @@ amd64_set_ioperm(td, uap) char *iomap; struct amd64tss *tssp; struct system_segment_descriptor *tss_sd; - u_long *addr; struct pcb *pcb; if ((error = priv_check(td, PRIV_IO)) != 0) @@ -361,9 +360,7 @@ amd64_set_ioperm(td, uap) if (tssp == NULL) return (ENOMEM); iomap = (char *)&tssp[1]; - addr = (u_long *)iomap; - for (i = 0; i < (ctob(IOPAGES) + 1) / sizeof(u_long); i++) - *addr++ = ~0; + memset(iomap, 0xff, IOPERM_BITMAP_SIZE); critical_enter(); /* Takes care of tss_rsp0. */ memcpy(tssp, &common_tss[PCPU_GET(cpuid)], diff --git a/sys/amd64/include/param.h b/sys/amd64/include/param.h index 3d4722b..7dcd7dd 100644 --- a/sys/amd64/include/param.h +++ b/sys/amd64/include/param.h @@ -120,6 +120,12 @@ #define MAXPAGESIZES 3 /* maximum number of supported page sizes */ #define IOPAGES 2 /* pages of i/o permission bitmap */ +/* + * I/O permission bitmap has a bit for each I/O port plus an additional + * byte at the end with all bits set. See section "I/O Permission Bit Map" + * in the Intel SDM for more details. + */ +#define IOPERM_BITMAP_SIZE (IOPAGES * PAGE_SIZE + 1) #ifndef KSTACK_PAGES #define KSTACK_PAGES 4 /* pages of kstack (with pcb) */ |