Re: [PATCH] powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
Frederic Barratwrites: > Le 13/10/2016 à 12:51, Michael Ellerman a écrit : >> Frederic Barrat writes: >> >>> ping? The patch still applies cleanly on recent trees. >> >> Fell through the cracks :/ >> >> Fixes: ? > > Nothing obvious. Current code was introduced by > 73d16a6e0e51990cbe13f8d8f43bd5329bbab30a > but it was apparently moved from cell, where the issue may not have > applied, I don't know. I guess we should use that id if really needed: > > Fixes: 73d16a6e0e51 ("powerpc/cell: Move data segment faulting code out of > cell platform") Yeah that works, it allows us to mechanically determine that "if you have backported 73d16a6e0e51 then you need this fix", which can be useful. cheers
Re: [PATCH] powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
Le 13/10/2016 à 12:51, Michael Ellerman a écrit : Frederic Barratwrites: ping? The patch still applies cleanly on recent trees. Fell through the cracks :/ Fixes: ? Nothing obvious. Current code was introduced by 73d16a6e0e51990cbe13f8d8f43bd5329bbab30a but it was apparently moved from cell, where the issue may not have applied, I don't know. I guess we should use that id if really needed: Fixes: 73d16a6e0e51 ("powerpc/cell: Move data segment faulting code out of cell platform") Fred
Re: [PATCH] powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
Frederic Barratwrites: > ping? The patch still applies cleanly on recent trees. Fell through the cracks :/ Fixes: ? cheers
Re: [PATCH] powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
ping? The patch still applies cleanly on recent trees. Fred Le 17/06/2016 à 18:53, Frederic Barrat a écrit : If a cxl adapter faults on an invalid address for a kernel context, we may enter copro_calculate_slb() with a NULL mm pointer (kernel context) and an effective address which looks like a user address. Which will cause a crash when dereferencing mm. It is clearly an AFU bug, but there's no reason to crash either. So return an error, so that cxl can ack the interrupt with an address error. Signed-off-by: Frederic BarratCc: --- arch/powerpc/mm/copro_fault.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c index 6527882..ddfd274 100644 --- a/arch/powerpc/mm/copro_fault.c +++ b/arch/powerpc/mm/copro_fault.c @@ -106,6 +106,8 @@ int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb) switch (REGION_ID(ea)) { case USER_REGION_ID: pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea); + if (mm == NULL) + return 1; psize = get_slice_psize(mm, ea); ssize = user_segment_size(ea); vsid = get_vsid(mm->context.id, ea, ssize);
Re: [PATCH] powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
Acked-by: Ian Munsie___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH] powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
If a cxl adapter faults on an invalid address for a kernel context, we may enter copro_calculate_slb() with a NULL mm pointer (kernel context) and an effective address which looks like a user address. Which will cause a crash when dereferencing mm. It is clearly an AFU bug, but there's no reason to crash either. So return an error, so that cxl can ack the interrupt with an address error. Signed-off-by: Frederic BarratCc: --- arch/powerpc/mm/copro_fault.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c index 6527882..ddfd274 100644 --- a/arch/powerpc/mm/copro_fault.c +++ b/arch/powerpc/mm/copro_fault.c @@ -106,6 +106,8 @@ int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb) switch (REGION_ID(ea)) { case USER_REGION_ID: pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea); + if (mm == NULL) + return 1; psize = get_slice_psize(mm, ea); ssize = user_segment_size(ea); vsid = get_vsid(mm->context.id, ea, ssize); -- 2.7.4 ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev