Christophe Leroy <christophe.le...@csgroup.eu> writes: > Le 15/03/2021 à 23:04, Nicholas Piggin a écrit : >> This extends the MSR[RI]=0 window a little further into the system >> call in order to pair RI and EE enabling with a single mtmsrd. > > Time ago, I proposed to delay that on PPC32 and Michael objected, see > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/9f9dd859d571e324c7412ed9db9da8cfba678257.1548956511.git.christophe.le...@c-s.fr/
I don't think I objected, I was just curious about what the added exposure to RI=0 was :) cheers >> diff --git a/arch/powerpc/kernel/exceptions-64s.S >> b/arch/powerpc/kernel/exceptions-64s.S >> index bd0c82ac9de5..2f14ac3c377c 100644 >> --- a/arch/powerpc/kernel/exceptions-64s.S >> +++ b/arch/powerpc/kernel/exceptions-64s.S >> @@ -1999,8 +1999,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE) >> mtctr r10 >> bctr >> .else >> - li r10,MSR_RI >> - mtmsrd r10,1 /* Set RI (EE=0) */ >> #ifdef CONFIG_RELOCATABLE >> __LOAD_HANDLER(r10, system_call_common) >> mtctr r10 >> diff --git a/arch/powerpc/kernel/interrupt_64.S >> b/arch/powerpc/kernel/interrupt_64.S >> index f28f41a1a85a..eef61800f734 100644 >> --- a/arch/powerpc/kernel/interrupt_64.S >> +++ b/arch/powerpc/kernel/interrupt_64.S >> @@ -311,10 +311,10 @@ END_BTB_FLUSH_SECTION >> * nothing pending. system_call_exception() will call >> * trace_hardirqs_off(). >> */ >> - li r11,IRQS_ALL_DISABLED >> - li r12,PACA_IRQ_HARD_DIS >> + li r11,IRQS_DISABLED >> + li r12,-1 /* Set MSR_EE and MSR_RI */ >> stb r11,PACAIRQSOFTMASK(r13) >> - stb r12,PACAIRQHAPPENED(r13) >> + mtmsrd r12,1 >> >> ENTER_KERNEL_SECURITY_FALLBACK >> >>
