Re: [PATCH v4] PPC: use CURRENT_THREAD_INFO instead of open coded assembly
On Thu, Jul 05, 2012 at 09:41:35AM -0500, Stuart Yoder wrote: diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index ba3aeb4..bad42e3 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -92,7 +92,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -112,7 +112,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif Do you really mean to replace a rlwimi with a rlwinm? If so, is that because the rlwinm is a bug fix, or is it because you know something special about KSP_LIMIT(r8) which means that rlwinm and rlwimi are equivalent here? Paul. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v4] PPC: use CURRENT_THREAD_INFO instead of open coded assembly
On Fri, 2012-07-13 at 08:45 +1000, Paul Mackerras wrote: On Thu, Jul 05, 2012 at 09:41:35AM -0500, Stuart Yoder wrote: diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index ba3aeb4..bad42e3 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -92,7 +92,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -112,7 +112,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif Do you really mean to replace a rlwimi with a rlwinm? If so, is that because the rlwinm is a bug fix, or is it because you know something special about KSP_LIMIT(r8) which means that rlwinm and rlwimi are equivalent here? Ah that's an interesting one I hadn't spotted when reviewing. Both variants (rlwimi and rlwinm) will effectively replace the top bits of KSP_LIMIT, switching it to the current stack. The difference is that the original one (rlwimi) will preserve the bottom bits. Now, do we want those bottom bits ? It looks like we do if we want to make the thread_info at the bottom of the stack as out of bounds. So the patch breaks that. It will not generally break a working kernel but the stack overflow detection may not trigger if the overflow is just enough to override the thread infos. Stuart, I already applied v4 of the patch to powerpc-next and I'd rather not rebase it, can you send a fixup patch please, one that will effecticely revert those two hunks, we can leave that open coded. While at it, please add a comment explaining what the code does to avoid similar confusion in the future. Cheers, Ben. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v4] PPC: use CURRENT_THREAD_INFO instead of open coded assembly
On 05.07.2012, at 16:41, Stuart Yoder wrote: From: Stuart Yoder stuart.yo...@freescale.com Signed-off-by: Stuart Yoder stuart.yo...@freescale.com Ben, ping? Alex --- -v4: fixed build issues in exception-64s.h and exceptions-64s.S arch/powerpc/include/asm/exception-64s.h |4 ++-- arch/powerpc/include/asm/thread_info.h |6 ++ arch/powerpc/kernel/entry_32.S | 24 arch/powerpc/kernel/entry_64.S | 14 +++--- arch/powerpc/kernel/exceptions-64e.S |2 +- arch/powerpc/kernel/exceptions-64s.S |2 +- arch/powerpc/kernel/head_fsl_booke.S |2 +- arch/powerpc/kernel/idle_6xx.S |4 ++-- arch/powerpc/kernel/idle_book3e.S|2 +- arch/powerpc/kernel/idle_e500.S |4 ++-- arch/powerpc/kernel/idle_power4.S|2 +- arch/powerpc/kernel/misc_32.S|4 ++-- arch/powerpc/kvm/bookehv_interrupts.S|6 +- arch/powerpc/mm/hash_low_32.S|8 arch/powerpc/sysdev/6xx-suspend.S|2 +- 15 files changed, 44 insertions(+), 42 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index d58fc4e..a43c147 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -293,7 +293,7 @@ label##_hv: \ #define RUNLATCH_ON \ BEGIN_FTR_SECTION \ - clrrdi r3,r1,THREAD_SHIFT; \ + CURRENT_THREAD_INFO(r3, r1);\ ld r4,TI_LOCAL_FLAGS(r3); \ andi. r0,r4,_TLF_RUNLATCH;\ beqlppc64_runlatch_on_trampoline; \ @@ -332,7 +332,7 @@ label##_common: \ #ifdef CONFIG_PPC_970_NAP #define FINISH_NAP\ BEGIN_FTR_SECTION \ - clrrdi r11,r1,THREAD_SHIFT;\ + CURRENT_THREAD_INFO(r11, r1); \ ld r9,TI_LOCAL_FLAGS(r11); \ andi. r10,r9,_TLF_NAPPING;\ bnelpower4_fixup_nap; \ diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 68831e9..faf9352 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -22,6 +22,12 @@ #define THREAD_SIZE (1 THREAD_SHIFT) +#ifdef CONFIG_PPC64 +#define CURRENT_THREAD_INFO(dest, sp)clrrdi dest, sp, THREAD_SHIFT +#else +#define CURRENT_THREAD_INFO(dest, sp)rlwinm dest, sp, 0, 0, 31-THREAD_SHIFT +#endif + #ifndef __ASSEMBLY__ #include linux/cache.h #include asm/processor.h diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index ba3aeb4..bad42e3 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -92,7 +92,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -112,7 +112,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -158,7 +158,7 @@ transfer_to_handler: tophys(r11,r11) addir11,r11,global_dbcr0@l #ifdef CONFIG_SMP - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r9, r1) lwz r9,TI_CPU(r9) slwir9,r9,3 add r11,r11,r9 @@ -179,7 +179,7 @@ transfer_to_handler: ble-stack_ovf /* then the kernel stack overflowed */ 5: #if defined(CONFIG_6xx) || defined(CONFIG_E500) - rlwinm r9,r1,0,0,31-THREAD_SHIFT + CURRENT_THREAD_INFO(r9, r1) tophys(r9,r9) /* check local flags */ lwz r12,TI_LOCAL_FLAGS(r9) mtcrf 0x01,r12 @@ -333,7 +333,7 @@ _GLOBAL(DoSyscall) mtmsr r11 1: #endif /* CONFIG_TRACE_IRQFLAGS */ - rlwinm r10,r1,0,0,(31-THREAD_SHIFT)/* current_thread_info() */ + CURRENT_THREAD_INFO(r10, r1) lwz r11,TI_FLAGS(r10) andi. r11,r11,_TIF_SYSCALL_T_OR_A bne-syscall_dotrace @@ -354,7 +354,7 @@ ret_from_syscall: bl do_show_syscall_exit #endif mr r6,r3 - rlwinm r12,r1,0,0,(31-THREAD_SHIFT)/* current_thread_info() */ + CURRENT_THREAD_INFO(r12, r1) /* disable interrupts so current_thread_info()-flags can't change */ LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */ /* Note: We don't bother telling lockdep about
[PATCH v4] PPC: use CURRENT_THREAD_INFO instead of open coded assembly
From: Stuart Yoder stuart.yo...@freescale.com Signed-off-by: Stuart Yoder stuart.yo...@freescale.com --- -v4: fixed build issues in exception-64s.h and exceptions-64s.S arch/powerpc/include/asm/exception-64s.h |4 ++-- arch/powerpc/include/asm/thread_info.h |6 ++ arch/powerpc/kernel/entry_32.S | 24 arch/powerpc/kernel/entry_64.S | 14 +++--- arch/powerpc/kernel/exceptions-64e.S |2 +- arch/powerpc/kernel/exceptions-64s.S |2 +- arch/powerpc/kernel/head_fsl_booke.S |2 +- arch/powerpc/kernel/idle_6xx.S |4 ++-- arch/powerpc/kernel/idle_book3e.S|2 +- arch/powerpc/kernel/idle_e500.S |4 ++-- arch/powerpc/kernel/idle_power4.S|2 +- arch/powerpc/kernel/misc_32.S|4 ++-- arch/powerpc/kvm/bookehv_interrupts.S|6 +- arch/powerpc/mm/hash_low_32.S|8 arch/powerpc/sysdev/6xx-suspend.S|2 +- 15 files changed, 44 insertions(+), 42 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index d58fc4e..a43c147 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -293,7 +293,7 @@ label##_hv: \ #define RUNLATCH_ON\ BEGIN_FTR_SECTION \ - clrrdi r3,r1,THREAD_SHIFT; \ + CURRENT_THREAD_INFO(r3, r1);\ ld r4,TI_LOCAL_FLAGS(r3); \ andi. r0,r4,_TLF_RUNLATCH;\ beqlppc64_runlatch_on_trampoline; \ @@ -332,7 +332,7 @@ label##_common: \ #ifdef CONFIG_PPC_970_NAP #define FINISH_NAP \ BEGIN_FTR_SECTION \ - clrrdi r11,r1,THREAD_SHIFT;\ + CURRENT_THREAD_INFO(r11, r1); \ ld r9,TI_LOCAL_FLAGS(r11); \ andi. r10,r9,_TLF_NAPPING;\ bnelpower4_fixup_nap; \ diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 68831e9..faf9352 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -22,6 +22,12 @@ #define THREAD_SIZE(1 THREAD_SHIFT) +#ifdef CONFIG_PPC64 +#define CURRENT_THREAD_INFO(dest, sp) clrrdi dest, sp, THREAD_SHIFT +#else +#define CURRENT_THREAD_INFO(dest, sp) rlwinm dest, sp, 0, 0, 31-THREAD_SHIFT +#endif + #ifndef __ASSEMBLY__ #include linux/cache.h #include asm/processor.h diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index ba3aeb4..bad42e3 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -92,7 +92,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -112,7 +112,7 @@ crit_transfer_to_handler: mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r0, r1) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -158,7 +158,7 @@ transfer_to_handler: tophys(r11,r11) addir11,r11,global_dbcr0@l #ifdef CONFIG_SMP - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r9, r1) lwz r9,TI_CPU(r9) slwir9,r9,3 add r11,r11,r9 @@ -179,7 +179,7 @@ transfer_to_handler: ble-stack_ovf /* then the kernel stack overflowed */ 5: #if defined(CONFIG_6xx) || defined(CONFIG_E500) - rlwinm r9,r1,0,0,31-THREAD_SHIFT + CURRENT_THREAD_INFO(r9, r1) tophys(r9,r9) /* check local flags */ lwz r12,TI_LOCAL_FLAGS(r9) mtcrf 0x01,r12 @@ -333,7 +333,7 @@ _GLOBAL(DoSyscall) mtmsr r11 1: #endif /* CONFIG_TRACE_IRQFLAGS */ - rlwinm r10,r1,0,0,(31-THREAD_SHIFT)/* current_thread_info() */ + CURRENT_THREAD_INFO(r10, r1) lwz r11,TI_FLAGS(r10) andi. r11,r11,_TIF_SYSCALL_T_OR_A bne-syscall_dotrace @@ -354,7 +354,7 @@ ret_from_syscall: bl do_show_syscall_exit #endif mr r6,r3 - rlwinm r12,r1,0,0,(31-THREAD_SHIFT)/* current_thread_info() */ + CURRENT_THREAD_INFO(r12, r1) /* disable interrupts so current_thread_info()-flags can't change */ LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */ /* Note: We don't bother telling lockdep about it */ @@ -815,7 +815,7 @@ ret_from_except: user_exc_return:
