| Message ID | 20241217034807.2541349-1-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/ptdump: Drop GENERIC_PTDUMP | expand |
Le 17/12/2024 à 04:48, Anshuman Khandual a écrit : > GENERIC_PTDUMP does not guard any code but instead just used for platform's > subscription into core ptdump defined under PTDUMP_CORE, which is selected. > Instead use PTDUMP_CORE for platform subscription and drop GENERIC_PTDUMP. > > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Jonathan Corbet <corbet@lwn.net> > Cc: Marc Zyngier <maz@kernel.org> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Nicholas Piggin <npiggin@gmail.com> > Cc: Paul Walmsley <paul.walmsley@sifive.com> > Cc: Palmer Dabbelt <palmer@dabbelt.com> > Cc: Heiko Carstens <hca@linux.ibm.com> > Cc: Vasily Gorbik <gor@linux.ibm.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-doc@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: kvmarm@lists.linux.dev > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-riscv@lists.infradead.org > Cc: linux-s390@vger.kernel.org > Cc: linux-mm@kvack.org > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > --- > This patch applies on v6.13-rc3 and has been tested on arm64, although it > also clears build tests on impacted platforms. > > Documentation/arch/arm64/ptdump.rst | 1 - > arch/arm64/Kconfig | 2 +- > arch/arm64/kvm/Kconfig | 3 +-- > arch/powerpc/Kconfig | 2 +- > arch/powerpc/configs/mpc885_ads_defconfig | 1 - > arch/riscv/Kconfig | 2 +- > arch/s390/Kconfig | 2 +- > arch/x86/Kconfig | 2 +- > arch/x86/Kconfig.debug | 2 +- > kernel/configs/debug.config | 1 - > mm/Kconfig.debug | 8 ++------ > 11 files changed, 9 insertions(+), 17 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index a0ce777f9706..c716f8df10de 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -203,7 +203,7 @@ config PPC > select GENERIC_IRQ_SHOW > select GENERIC_IRQ_SHOW_LEVEL > select GENERIC_PCI_IOMAP if PCI > - select GENERIC_PTDUMP > + select PTDUMP_CORE Please keep alphabetical order. > select GENERIC_SMP_IDLE_THREAD > select GENERIC_TIME_VSYSCALL > select GENERIC_VDSO_TIME_NS > diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug > index 41a58536531d..b206e5a11f96 100644 > --- a/mm/Kconfig.debug > +++ b/mm/Kconfig.debug > @@ -187,7 +187,7 @@ config DEBUG_WX > bool "Warn on W+X mappings at boot" > depends on ARCH_HAS_DEBUG_WX > depends on MMU > - select PTDUMP_CORE > + depends on PTDUMP_CORE This change is unclear to me. It works because all arch selecting ARCH_HAS_DEBUG_WX also select GENERIC_PTDUMP. For riscv it's even more tricking, Riscv only selects GENERIC_PTDUMP when MMU is set, so it works because here it also depends on MMU. But what happens if in the future an architecture selects ARCH_HAS_DEBUG_WX without selecting PTDUMP_CORE ? > help > Generate a warning if any W+X mappings are found at boot. > > @@ -212,9 +212,6 @@ config DEBUG_WX > > If in doubt, say "Y". > > -config GENERIC_PTDUMP > - bool > - > config PTDUMP_CORE > bool > > @@ -222,8 +219,7 @@ config PTDUMP_DEBUGFS > bool "Export kernel pagetable layout to userspace via debugfs" > depends on DEBUG_KERNEL > depends on DEBUG_FS > - depends on GENERIC_PTDUMP > - select PTDUMP_CORE > + depends on PTDUMP_CORE > help > Say Y here if you want to show the kernel pagetable layout in a > debugfs file. This information is only useful for kernel developers
On 12/17/24 13:17, Christophe Leroy wrote: > > > Le 17/12/2024 à 04:48, Anshuman Khandual a écrit : >> GENERIC_PTDUMP does not guard any code but instead just used for platform's >> subscription into core ptdump defined under PTDUMP_CORE, which is selected. >> Instead use PTDUMP_CORE for platform subscription and drop GENERIC_PTDUMP. >> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> Cc: Will Deacon <will@kernel.org> >> Cc: Jonathan Corbet <corbet@lwn.net> >> Cc: Marc Zyngier <maz@kernel.org> >> Cc: Michael Ellerman <mpe@ellerman.id.au> >> Cc: Nicholas Piggin <npiggin@gmail.com> >> Cc: Paul Walmsley <paul.walmsley@sifive.com> >> Cc: Palmer Dabbelt <palmer@dabbelt.com> >> Cc: Heiko Carstens <hca@linux.ibm.com> >> Cc: Vasily Gorbik <gor@linux.ibm.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Ingo Molnar <mingo@redhat.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-doc@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Cc: kvmarm@lists.linux.dev >> Cc: linuxppc-dev@lists.ozlabs.org >> Cc: linux-riscv@lists.infradead.org >> Cc: linux-s390@vger.kernel.org >> Cc: linux-mm@kvack.org >> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> >> --- >> This patch applies on v6.13-rc3 and has been tested on arm64, although it >> also clears build tests on impacted platforms. >> >> Documentation/arch/arm64/ptdump.rst | 1 - >> arch/arm64/Kconfig | 2 +- >> arch/arm64/kvm/Kconfig | 3 +-- >> arch/powerpc/Kconfig | 2 +- >> arch/powerpc/configs/mpc885_ads_defconfig | 1 - >> arch/riscv/Kconfig | 2 +- >> arch/s390/Kconfig | 2 +- >> arch/x86/Kconfig | 2 +- >> arch/x86/Kconfig.debug | 2 +- >> kernel/configs/debug.config | 1 - >> mm/Kconfig.debug | 8 ++------ >> 11 files changed, 9 insertions(+), 17 deletions(-) >> > >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index a0ce777f9706..c716f8df10de 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -203,7 +203,7 @@ config PPC >> select GENERIC_IRQ_SHOW >> select GENERIC_IRQ_SHOW_LEVEL >> select GENERIC_PCI_IOMAP if PCI >> - select GENERIC_PTDUMP >> + select PTDUMP_CORE > > Please keep alphabetical order. Sure, will do that. > >> select GENERIC_SMP_IDLE_THREAD >> select GENERIC_TIME_VSYSCALL >> select GENERIC_VDSO_TIME_NS > >> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug >> index 41a58536531d..b206e5a11f96 100644 >> --- a/mm/Kconfig.debug >> +++ b/mm/Kconfig.debug >> @@ -187,7 +187,7 @@ config DEBUG_WX >> bool "Warn on W+X mappings at boot" >> depends on ARCH_HAS_DEBUG_WX >> depends on MMU >> - select PTDUMP_CORE >> + depends on PTDUMP_CORE > > This change is unclear to me. It works because all arch selecting ARCH_HAS_DEBUG_WX also select GENERIC_PTDUMP. For riscv it's even more tricking, Riscv only selects GENERIC_PTDUMP when MMU is set, so it works because here it also depends on MMU. Right, all the archs selecting ARCH_HAS_DEBUG_WX also select PTDUMP_CORE. DEBUG_WX dependency on PTDUMP_CORE will always be met, when the platform selects ARCH_HAS_DEBUG_WX as expected. git grep "select PTDUMP_CORE" arch/ arch/arm64/Kconfig: select PTDUMP_CORE arch/powerpc/Kconfig: select PTDUMP_CORE arch/riscv/Kconfig: select PTDUMP_CORE if MMU arch/s390/Kconfig: select PTDUMP_CORE arch/x86/Kconfig: select PTDUMP_CORE git grep ARCH_HAS_DEBUG_WX arch/ arch/arm64/Kconfig: select ARCH_HAS_DEBUG_WX arch/powerpc/Kconfig: select ARCH_HAS_DEBUG_WX if STRICT_KERNEL_RWX arch/riscv/Kconfig: select ARCH_HAS_DEBUG_WX arch/s390/Kconfig: select ARCH_HAS_DEBUG_WX arch/x86/Kconfig: select ARCH_HAS_DEBUG_WX On riscv platform, does not PTDUMP_CORE implicitly imply existence of MMU ? Could there be a page table dumper without a MMU. > > But what happens if in the future an architecture selects ARCH_HAS_DEBUG_WX without selecting PTDUMP_CORE ? Should DEBUG_WX just select PTDUMP_CORE as it exists now. A platform will be able to get PTDUMP_CORE via DEBUG_WX if ARCH_HAS_DEBUG_WX is subscribed into. Would that be better ? > > >> help >> Generate a warning if any W+X mappings are found at boot. >> @@ -212,9 +212,6 @@ config DEBUG_WX >> If in doubt, say "Y". >> -config GENERIC_PTDUMP >> - bool >> - >> config PTDUMP_CORE >> bool >> @@ -222,8 +219,7 @@ config PTDUMP_DEBUGFS >> bool "Export kernel pagetable layout to userspace via debugfs" >> depends on DEBUG_KERNEL >> depends on DEBUG_FS >> - depends on GENERIC_PTDUMP >> - select PTDUMP_CORE >> + depends on PTDUMP_CORE >> help >> Say Y here if you want to show the kernel pagetable layout in a >> debugfs file. This information is only useful for kernel developers >
diff --git a/Documentation/arch/arm64/ptdump.rst b/Documentation/arch/arm64/ptdump.rst index 5dcfc5d7cddf..61ca040a885b 100644 --- a/Documentation/arch/arm64/ptdump.rst +++ b/Documentation/arch/arm64/ptdump.rst @@ -22,7 +22,6 @@ offlining of memory being accessed by the ptdump code. In order to dump the kernel page tables, enable the following configurations and mount debugfs:: - CONFIG_GENERIC_PTDUMP=y CONFIG_PTDUMP_CORE=y CONFIG_PTDUMP_DEBUGFS=y diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 100570a048c5..b5479c8b454c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -154,7 +154,7 @@ config ARM64 select GENERIC_IRQ_SHOW_LEVEL select GENERIC_LIB_DEVMEM_IS_ALLOWED select GENERIC_PCI_IOMAP - select GENERIC_PTDUMP + select PTDUMP_CORE select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index ead632ad01b4..fe17d7f5b061 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -71,8 +71,7 @@ config PTDUMP_STAGE2_DEBUGFS depends on KVM depends on DEBUG_KERNEL depends on DEBUG_FS - depends on GENERIC_PTDUMP - select PTDUMP_CORE + depends on PTDUMP_CORE default n help Say Y here if you want to show the stage-2 kernel pagetables diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index a0ce777f9706..c716f8df10de 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -203,7 +203,7 @@ config PPC select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL select GENERIC_PCI_IOMAP if PCI - select GENERIC_PTDUMP + select PTDUMP_CORE select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL select GENERIC_VDSO_TIME_NS diff --git a/arch/powerpc/configs/mpc885_ads_defconfig b/arch/powerpc/configs/mpc885_ads_defconfig index 77306be62e9e..ea6f836407d2 100644 --- a/arch/powerpc/configs/mpc885_ads_defconfig +++ b/arch/powerpc/configs/mpc885_ads_defconfig @@ -78,4 +78,3 @@ CONFIG_DEBUG_VM_PGTABLE=y CONFIG_DETECT_HUNG_TASK=y CONFIG_BDI_SWITCH=y CONFIG_PPC_EARLY_DEBUG=y -CONFIG_GENERIC_PTDUMP=y diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index d4a7ca0388c0..05f969729e72 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -111,7 +111,7 @@ config RISCV select GENERIC_IRQ_SHOW_LEVEL select GENERIC_LIB_DEVMEM_IS_ALLOWED select GENERIC_PCI_IOMAP - select GENERIC_PTDUMP if MMU + select PTDUMP_CORE if MMU select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL if MMU && 64BIT diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 0077969170e8..0e19fe547d84 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -155,7 +155,7 @@ config S390 select GENERIC_CPU_VULNERABILITIES select GENERIC_ENTRY select GENERIC_GETTIMEOFDAY - select GENERIC_PTDUMP + select PTDUMP_CORE select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL select GENERIC_VDSO_TIME_NS diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9d7bd0ae48c4..d84cb2ac93ac 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -173,7 +173,7 @@ config X86 select GENERIC_IRQ_RESERVATION_MODE select GENERIC_IRQ_SHOW select GENERIC_PENDING_IRQ if SMP - select GENERIC_PTDUMP + select PTDUMP_CORE select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL select GENERIC_GETTIMEOFDAY diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 74777a97e394..198d7f090b98 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -59,7 +59,7 @@ config EARLY_PRINTK_USB_XDBC config EFI_PGT_DUMP bool "Dump the EFI pagetable" depends on EFI - select PTDUMP_CORE + depends on PTDUMP_CORE help Enable this if you want to dump the EFI page table before enabling virtual mode. This can be used to debug miscellaneous diff --git a/kernel/configs/debug.config b/kernel/configs/debug.config index 20552f163930..8aafd050b754 100644 --- a/kernel/configs/debug.config +++ b/kernel/configs/debug.config @@ -73,7 +73,6 @@ CONFIG_DEBUG_VM=y CONFIG_DEBUG_VM_PGFLAGS=y CONFIG_DEBUG_VM_RB=y CONFIG_DEBUG_VM_VMACACHE=y -CONFIG_GENERIC_PTDUMP=y CONFIG_KASAN=y CONFIG_KASAN_GENERIC=y CONFIG_KASAN_INLINE=y diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 41a58536531d..b206e5a11f96 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -187,7 +187,7 @@ config DEBUG_WX bool "Warn on W+X mappings at boot" depends on ARCH_HAS_DEBUG_WX depends on MMU - select PTDUMP_CORE + depends on PTDUMP_CORE help Generate a warning if any W+X mappings are found at boot. @@ -212,9 +212,6 @@ config DEBUG_WX If in doubt, say "Y". -config GENERIC_PTDUMP - bool - config PTDUMP_CORE bool @@ -222,8 +219,7 @@ config PTDUMP_DEBUGFS bool "Export kernel pagetable layout to userspace via debugfs" depends on DEBUG_KERNEL depends on DEBUG_FS - depends on GENERIC_PTDUMP - select PTDUMP_CORE + depends on PTDUMP_CORE help Say Y here if you want to show the kernel pagetable layout in a debugfs file. This information is only useful for kernel developers
GENERIC_PTDUMP does not guard any code but instead just used for platform's subscription into core ptdump defined under PTDUMP_CORE, which is selected. Instead use PTDUMP_CORE for platform subscription and drop GENERIC_PTDUMP. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: kvmarm@lists.linux.dev Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- This patch applies on v6.13-rc3 and has been tested on arm64, although it also clears build tests on impacted platforms. Documentation/arch/arm64/ptdump.rst | 1 - arch/arm64/Kconfig | 2 +- arch/arm64/kvm/Kconfig | 3 +-- arch/powerpc/Kconfig | 2 +- arch/powerpc/configs/mpc885_ads_defconfig | 1 - arch/riscv/Kconfig | 2 +- arch/s390/Kconfig | 2 +- arch/x86/Kconfig | 2 +- arch/x86/Kconfig.debug | 2 +- kernel/configs/debug.config | 1 - mm/Kconfig.debug | 8 ++------ 11 files changed, 9 insertions(+), 17 deletions(-)