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| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2011-08-31 02:10:05 +0200 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2011-08-31 02:10:05 +0200 |
| commit | fa57c51ac74a8301db7ab8b2fc9cbd63d69d26b3 (patch) | |
| tree | bbe466379fb371715c43700baabf5b66012e8577 | |
| parent | 317e678d6d0bff1be16383a6ef9d914f28aebb74 (diff) | |
Disable global page while writing in kernel space
* i386/i386/db_interface.c (db_write_bytes): If CPU has PGE feature, disable
CR4_PGE before enabling kernel page write access, and re-enable the former after
disabling the latter.
| -rw-r--r-- | i386/i386/db_interface.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/i386/i386/db_interface.c b/i386/i386/db_interface.c index d149adc..c07884d 100644 --- a/i386/i386/db_interface.c +++ b/i386/i386/db_interface.c @@ -39,6 +39,7 @@ #include <i386/setjmp.h> #include <i386/pmap.h> #include <i386/proc_reg.h> +#include <i386/locore.h> #include "gdt.h" #include "trap.h" @@ -390,6 +391,8 @@ db_write_bytes( oldmap1 = *ptep1; *ptep1 |= INTEL_PTE_WRITE; } + if (CPU_HAS_FEATURE(CPU_FEATURE_PGE)) + set_cr4(get_cr4() & ~CR4_PGE); flush_tlb(); } @@ -404,6 +407,8 @@ db_write_bytes( *ptep1 = oldmap1; } flush_tlb(); + if (CPU_HAS_FEATURE(CPU_FEATURE_PGE)) + set_cr4(get_cr4() | CR4_PGE); } } |