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| author | David S. Miller <davem@davemloft.net> | 2016-07-28 03:50:26 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-07-28 03:50:26 +0300 |
| commit | 4f6deb8cbab532a8d7250bc09234c1795ecb5e2c (patch) | |
| tree | 96a786e93f7da67cec53197cd148da61789b5ea4 | |
| parent | 8448cefe499a45222430ebbcabcd9e26369895c3 (diff) | |
| download | linux-4f6deb8cbab532a8d7250bc09234c1795ecb5e2c.tar.xz | |
sparc: Don't leak context bits into thread->fault_address
On pre-Niagara systems, we fetch the fault address on data TLB
exceptions from the TLB_TAG_ACCESS register. But this register also
contains the context ID assosciated with the fault in the low 13 bits
of the register value.
This propagates into current_thread_info()->fault_address and can
cause trouble later on.
So clear the low 13-bits out of the TLB_TAG_ACCESS value in the cases
where it matters.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | arch/sparc/kernel/dtlb_prot.S | 4 | ||||
| -rw-r--r-- | arch/sparc/kernel/ktlb.S | 12 | ||||
| -rw-r--r-- | arch/sparc/kernel/tsb.S | 12 |
3 files changed, 24 insertions, 4 deletions
diff --git a/arch/sparc/kernel/dtlb_prot.S b/arch/sparc/kernel/dtlb_prot.S index d668ca149e64..4087a62f96b0 100644 --- a/arch/sparc/kernel/dtlb_prot.S +++ b/arch/sparc/kernel/dtlb_prot.S @@ -25,13 +25,13 @@ /* PROT ** ICACHE line 2: More real fault processing */ ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5 + srlx %g5, PAGE_SHIFT, %g5 + sllx %g5, PAGE_SHIFT, %g5 ! Clear context ID bits bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4 ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault nop nop - nop - nop /* PROT ** ICACHE line 3: Unused... */ nop diff --git a/arch/sparc/kernel/ktlb.S b/arch/sparc/kernel/ktlb.S index ef0d8e9e1210..f22bec0db645 100644 --- a/arch/sparc/kernel/ktlb.S +++ b/arch/sparc/kernel/ktlb.S @@ -20,6 +20,10 @@ kvmap_itlb: mov TLB_TAG_ACCESS, %g4 ldxa [%g4] ASI_IMMU, %g4 + /* The kernel executes in context zero, therefore we do not + * need to clear the context ID bits out of %g4 here. + */ + /* sun4v_itlb_miss branches here with the missing virtual * address already loaded into %g4 */ @@ -128,6 +132,10 @@ kvmap_dtlb: mov TLB_TAG_ACCESS, %g4 ldxa [%g4] ASI_DMMU, %g4 + /* The kernel executes in context zero, therefore we do not + * need to clear the context ID bits out of %g4 here. + */ + /* sun4v_dtlb_miss branches here with the missing virtual * address already loaded into %g4 */ @@ -251,6 +259,10 @@ kvmap_dtlb_longpath: nop .previous + /* The kernel executes in context zero, therefore we do not + * need to clear the context ID bits out of %g5 here. + */ + be,pt %xcc, sparc64_realfault_common mov FAULT_CODE_DTLB, %g4 ba,pt %xcc, winfix_trampoline diff --git a/arch/sparc/kernel/tsb.S b/arch/sparc/kernel/tsb.S index be98685c14c6..d568c8207af7 100644 --- a/arch/sparc/kernel/tsb.S +++ b/arch/sparc/kernel/tsb.S @@ -29,13 +29,17 @@ */ tsb_miss_dtlb: mov TLB_TAG_ACCESS, %g4 + ldxa [%g4] ASI_DMMU, %g4 + srlx %g4, PAGE_SHIFT, %g4 ba,pt %xcc, tsb_miss_page_table_walk - ldxa [%g4] ASI_DMMU, %g4 + sllx %g4, PAGE_SHIFT, %g4 tsb_miss_itlb: mov TLB_TAG_ACCESS, %g4 + ldxa [%g4] ASI_IMMU, %g4 + srlx %g4, PAGE_SHIFT, %g4 ba,pt %xcc, tsb_miss_page_table_walk - ldxa [%g4] ASI_IMMU, %g4 + sllx %g4, PAGE_SHIFT, %g4 /* At this point we have: * %g1 -- PAGE_SIZE TSB entry address @@ -284,6 +288,10 @@ tsb_do_dtlb_fault: nop .previous + /* Clear context ID bits. */ + srlx %g5, PAGE_SHIFT, %g5 + sllx %g5, PAGE_SHIFT, %g5 + be,pt %xcc, sparc64_realfault_common mov FAULT_CODE_DTLB, %g4 ba,pt %xcc, winfix_trampoline |