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Band-aid a problem with 32 bit selector setup.

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Initialize %ds, %es, and %fs during CPU startup.  Otherwise a garbage
value could leak to a 32-bit process if a process migrated to a different
CPU after exec and the new CPU had never exec'd a 32-bit process.

A more complete fix is needed, but this mitigates the most frequent
manifestations.

Obtained from:	ups
This commit is contained in:
Peter Wemm 2008-07-09 19:44:37 +00:00
parent e5cf427baf
commit 401989b00b
2 changed files with 9 additions and 1 deletions
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4
sys/amd64/amd64/machdep.c
View File

@ -1466,6 +1466,10 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
_udatasel = GSEL(GUDATA_SEL, SEL_UPL);
_ucode32sel = GSEL(GUCODE32_SEL, SEL_UPL);
load_ds(_udatasel);
load_es(_udatasel);
load_fs(_udatasel);
/* setup proc 0's pcb */
thread0.td_pcb->pcb_flags = 0;
thread0.td_pcb->pcb_cr3 = KPML4phys;

6
sys/amd64/amd64/mp_machdep.c
View File

@ -98,6 +98,8 @@ extern pt_entry_t *KPTphys;
/* SMP page table page */
extern pt_entry_t *SMPpt;
extern int _udatasel;
struct pcb stoppcbs[MAXCPU];
/* Variables needed for SMP tlb shootdown. */
@ -564,7 +566,9 @@ init_secondary(void)
*/
load_cr4(rcr4() | CR4_PGE);
load_ds(_udatasel);
load_es(_udatasel);
load_fs(_udatasel);
mtx_unlock_spin(&ap_boot_mtx);
/* wait until all the AP's are up */