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| Started by | Christophe Leroy <christophe.leroy@c-s.fr> |
|---|---|
| First post | 2017-04-14 15:40 +0200 |
| Last post | 2017-04-18 13:30 +0200 |
| Articles | 2 — 2 participants |
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[PATCH] powerpc/32: Remove redundant test in transfer_to_handler() Christophe Leroy <christophe.leroy@c-s.fr> - 2017-04-14 15:40 +0200
Re: [PATCH] powerpc/32: Remove redundant test in transfer_to_handler() Christophe LEROY <christophe.leroy@c-s.fr> - 2017-04-18 13:30 +0200
| From | Christophe Leroy <christophe.leroy@c-s.fr> |
|---|---|
| Date | 2017-04-14 15:40 +0200 |
| Subject | [PATCH] powerpc/32: Remove redundant test in transfer_to_handler() |
| Message-ID | <tw9Ca-1Db-3@gated-at.bofh.it> |
As stated in the comment on top of transfer_to_handler(), all callers set cr0.eq if the exception occurred in kernel mode (i.e. MSR:PR = 0) Therefore, it is not needed to do the test again Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/kernel/entry_32.S | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index a38600949f3a..0651a7438fa6 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -141,7 +141,6 @@ transfer_to_handler: stw r2,GPR2(r11) stw r12,_NIP(r11) stw r9,_MSR(r11) - andi. r2,r9,MSR_PR mfctr r12 mfspr r2,SPRN_XER stw r12,_CTR(r11) -- 2.12.0
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| From | Christophe LEROY <christophe.leroy@c-s.fr> |
|---|---|
| Date | 2017-04-18 13:30 +0200 |
| Subject | Re: [PATCH] powerpc/32: Remove redundant test in transfer_to_handler() |
| Message-ID | <txzux-5A7-1@gated-at.bofh.it> |
| In reply to | #1623664 |
Le 14/04/2017 à 15:31, Christophe Leroy a écrit : > As stated in the comment on top of transfer_to_handler(), > all callers set cr0.eq if the exception occurred in kernel mode > (i.e. MSR:PR = 0) > > Therefore, it is not needed to do the test again Indeed, all callers set cr0.eq as required .... except that some of them just destroy it by inserting another test before calling transfer_to_handler(). So this patch cannot be applied as is at the time being. Christophe > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > arch/powerpc/kernel/entry_32.S | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S > index a38600949f3a..0651a7438fa6 100644 > --- a/arch/powerpc/kernel/entry_32.S > +++ b/arch/powerpc/kernel/entry_32.S > @@ -141,7 +141,6 @@ transfer_to_handler: > stw r2,GPR2(r11) > stw r12,_NIP(r11) > stw r9,_MSR(r11) > - andi. r2,r9,MSR_PR > mfctr r12 > mfspr r2,SPRN_XER > stw r12,_CTR(r11) >
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