* [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack @ 2022-01-06 19:26 ` Ard Biesheuvel 2022-01-07 9:14 ` Geert Uytterhoeven 2022-01-10 9:36 ` Marek Szyprowski 0 siblings, 2 replies; 5+ messages in thread From: Ard Biesheuvel @ 2022-01-06 19:26 UTC (permalink / raw) To: linux Cc: linux-arm-kernel, arnd, linus.walleij, keescook, Ard Biesheuvel, Marek Szyprowski, Geert Uytterhoeven, Jon Hunter The resume from suspend code switches to the ID map so it can enable the MMU. On !LPAE configurations, the ID map carries its own copy of the kernel VA range, but this is not kept in sync with swapper_pg_dir, and so it may lack the mapping of the kernel mode stack if CONFIG_VMAP_STACK is enabled. So let's switch to swapper_pg_dir right after re-enabling the MMU on such configurations. This avoids a crash on resume observed on various platforms [0]. [0] https://lore.kernel.org/linux-arm-kernel/20211122092816.2865873-8-ardb@kernel.org/ Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- Please test with the Kconfig patch [9177/1] reverted. arch/arm/kernel/sleep.S | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index b062b3738bc6..6217ef90feb0 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -119,6 +119,13 @@ ENTRY(cpu_resume_mmu) ENDPROC(cpu_resume_mmu) .popsection cpu_resume_after_mmu: +#if defined(CONFIG_VMAP_STACK) && !defined(CONFIG_ARM_LPAE) + @ Before using the vmap'ed stack, we have to switch to swapper_pg_dir + @ as the ID map does not cover the vmalloc region. + mrc p15, 0, ip, c2, c0, 1 @ read TTBR1 + mcr p15, 0, ip, c2, c0, 0 @ set TTBR0 + isb +#endif bl cpu_init @ restore the und/abt/irq banked regs mov r0, #0 @ return zero on success ldmfd sp!, {r4 - r11, pc} -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack 2022-01-06 19:26 ` [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack Ard Biesheuvel @ 2022-01-07 9:14 ` Geert Uytterhoeven 2022-01-07 10:00 ` Ard Biesheuvel 2022-01-10 9:36 ` Marek Szyprowski 1 sibling, 1 reply; 5+ messages in thread From: Geert Uytterhoeven @ 2022-01-07 9:14 UTC (permalink / raw) To: Ard Biesheuvel Cc: Russell King, Linux ARM, Arnd Bergmann, Linus Walleij, Kees Cook, Marek Szyprowski, Jon Hunter, Linux-Renesas Hi Ard, On Thu, Jan 6, 2022 at 8:27 PM Ard Biesheuvel <ardb@kernel.org> wrote: > The resume from suspend code switches to the ID map so it can enable the > MMU. On !LPAE configurations, the ID map carries its own copy of the > kernel VA range, but this is not kept in sync with swapper_pg_dir, and > so it may lack the mapping of the kernel mode stack if CONFIG_VMAP_STACK > is enabled. > > So let's switch to swapper_pg_dir right after re-enabling the MMU on > such configurations. This avoids a crash on resume observed on various > platforms [0]. > > [0] https://lore.kernel.org/linux-arm-kernel/20211122092816.2865873-8-ardb@kernel.org/ > > Cc: Marek Szyprowski <m.szyprowski@samsung.com> > Cc: Geert Uytterhoeven <geert@linux-m68k.org> > Cc: Jon Hunter <jonathanh@nvidia.com> > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Thanks for your patch! This fixes s2ram on r8a7791/koelsch (dual Cortex-A15) with shmobile_defconfig. S2ram on sh73a0/kzm9g (dual Cortex-A9) works as before. Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > Please test with the Kconfig patch [9177/1] reverted. > > arch/arm/kernel/sleep.S | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S > index b062b3738bc6..6217ef90feb0 100644 > --- a/arch/arm/kernel/sleep.S > +++ b/arch/arm/kernel/sleep.S > @@ -119,6 +119,13 @@ ENTRY(cpu_resume_mmu) > ENDPROC(cpu_resume_mmu) > .popsection > cpu_resume_after_mmu: > +#if defined(CONFIG_VMAP_STACK) && !defined(CONFIG_ARM_LPAE) > + @ Before using the vmap'ed stack, we have to switch to swapper_pg_dir > + @ as the ID map does not cover the vmalloc region. > + mrc p15, 0, ip, c2, c0, 1 @ read TTBR1 > + mcr p15, 0, ip, c2, c0, 0 @ set TTBR0 > + isb > +#endif > bl cpu_init @ restore the und/abt/irq banked regs > mov r0, #0 @ return zero on success > ldmfd sp!, {r4 - r11, pc} Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack 2022-01-07 9:14 ` Geert Uytterhoeven @ 2022-01-07 10:00 ` Ard Biesheuvel 0 siblings, 0 replies; 5+ messages in thread From: Ard Biesheuvel @ 2022-01-07 10:00 UTC (permalink / raw) To: Geert Uytterhoeven Cc: Russell King, Linux ARM, Arnd Bergmann, Linus Walleij, Kees Cook, Marek Szyprowski, Jon Hunter, Linux-Renesas On Fri, 7 Jan 2022 at 10:15, Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > Hi Ard, > > On Thu, Jan 6, 2022 at 8:27 PM Ard Biesheuvel <ardb@kernel.org> wrote: > > The resume from suspend code switches to the ID map so it can enable the > > MMU. On !LPAE configurations, the ID map carries its own copy of the > > kernel VA range, but this is not kept in sync with swapper_pg_dir, and > > so it may lack the mapping of the kernel mode stack if CONFIG_VMAP_STACK > > is enabled. > > > > So let's switch to swapper_pg_dir right after re-enabling the MMU on > > such configurations. This avoids a crash on resume observed on various > > platforms [0]. > > > > [0] https://lore.kernel.org/linux-arm-kernel/20211122092816.2865873-8-ardb@kernel.org/ > > > > Cc: Marek Szyprowski <m.szyprowski@samsung.com> > > Cc: Geert Uytterhoeven <geert@linux-m68k.org> > > Cc: Jon Hunter <jonathanh@nvidia.com> > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > > Thanks for your patch! > > This fixes s2ram on r8a7791/koelsch (dual Cortex-A15) with > shmobile_defconfig. > S2ram on sh73a0/kzm9g (dual Cortex-A9) works as before. > > Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> > Thanks Geert. > > --- > > Please test with the Kconfig patch [9177/1] reverted. > > > > arch/arm/kernel/sleep.S | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S > > index b062b3738bc6..6217ef90feb0 100644 > > --- a/arch/arm/kernel/sleep.S > > +++ b/arch/arm/kernel/sleep.S > > @@ -119,6 +119,13 @@ ENTRY(cpu_resume_mmu) > > ENDPROC(cpu_resume_mmu) > > .popsection > > cpu_resume_after_mmu: > > +#if defined(CONFIG_VMAP_STACK) && !defined(CONFIG_ARM_LPAE) > > + @ Before using the vmap'ed stack, we have to switch to swapper_pg_dir > > + @ as the ID map does not cover the vmalloc region. > > + mrc p15, 0, ip, c2, c0, 1 @ read TTBR1 > > + mcr p15, 0, ip, c2, c0, 0 @ set TTBR0 > > + isb > > +#endif > > bl cpu_init @ restore the und/abt/irq banked regs > > mov r0, #0 @ return zero on success > > ldmfd sp!, {r4 - r11, pc} > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack 2022-01-06 19:26 ` [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack Ard Biesheuvel 2022-01-07 9:14 ` Geert Uytterhoeven @ 2022-01-10 9:36 ` Marek Szyprowski 2022-01-10 10:55 ` Ard Biesheuvel 1 sibling, 1 reply; 5+ messages in thread From: Marek Szyprowski @ 2022-01-10 9:36 UTC (permalink / raw) To: Ard Biesheuvel, linux Cc: linux-arm-kernel, arnd, linus.walleij, keescook, Geert Uytterhoeven, Jon Hunter Hi Ard, On 06.01.2022 20:26, Ard Biesheuvel wrote: > The resume from suspend code switches to the ID map so it can enable the > MMU. On !LPAE configurations, the ID map carries its own copy of the > kernel VA range, but this is not kept in sync with swapper_pg_dir, and > so it may lack the mapping of the kernel mode stack if CONFIG_VMAP_STACK > is enabled. > > So let's switch to swapper_pg_dir right after re-enabling the MMU on > such configurations. This avoids a crash on resume observed on various > platforms [0]. > > [0] https://protect2.fireeye.com/v1/url?k=efa2c314-b039fa16-efa3485b-0cc47a31381a-5dcf992b5d854429&q=1&e=1dac5900-a7aa-40ed-a2f0-9af17ae05bfe&u=https%3A%2F%2Flore.kernel.org%2Flinux-arm-kernel%2F20211122092816.2865873-8-ardb%40kernel.org%2F > > Cc: Marek Szyprowski <m.szyprowski@samsung.com> > Cc: Geert Uytterhoeven <geert@linux-m68k.org> > Cc: Jon Hunter <jonathanh@nvidia.com> > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> This fixes the suspend/resume issue observed on ARM 32bit Exynos based boards. Thanks! Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > Please test with the Kconfig patch [9177/1] reverted. > > arch/arm/kernel/sleep.S | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S > index b062b3738bc6..6217ef90feb0 100644 > --- a/arch/arm/kernel/sleep.S > +++ b/arch/arm/kernel/sleep.S > @@ -119,6 +119,13 @@ ENTRY(cpu_resume_mmu) > ENDPROC(cpu_resume_mmu) > .popsection > cpu_resume_after_mmu: > +#if defined(CONFIG_VMAP_STACK) && !defined(CONFIG_ARM_LPAE) > + @ Before using the vmap'ed stack, we have to switch to swapper_pg_dir > + @ as the ID map does not cover the vmalloc region. > + mrc p15, 0, ip, c2, c0, 1 @ read TTBR1 > + mcr p15, 0, ip, c2, c0, 0 @ set TTBR0 > + isb > +#endif > bl cpu_init @ restore the und/abt/irq banked regs > mov r0, #0 @ return zero on success > ldmfd sp!, {r4 - r11, pc} Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack 2022-01-10 9:36 ` Marek Szyprowski @ 2022-01-10 10:55 ` Ard Biesheuvel 0 siblings, 0 replies; 5+ messages in thread From: Ard Biesheuvel @ 2022-01-10 10:55 UTC (permalink / raw) To: Marek Szyprowski Cc: linux, linux-arm-kernel, arnd, linus.walleij, keescook, Geert Uytterhoeven, Jon Hunter On Mon, 10 Jan 2022 at 10:36, Marek Szyprowski <m.szyprowski@samsung.com> wrote: > > Hi Ard, > > On 06.01.2022 20:26, Ard Biesheuvel wrote: > > The resume from suspend code switches to the ID map so it can enable the > > MMU. On !LPAE configurations, the ID map carries its own copy of the > > kernel VA range, but this is not kept in sync with swapper_pg_dir, and > > so it may lack the mapping of the kernel mode stack if CONFIG_VMAP_STACK > > is enabled. > > > > So let's switch to swapper_pg_dir right after re-enabling the MMU on > > such configurations. This avoids a crash on resume observed on various > > platforms [0]. > > > > [0] https://protect2.fireeye.com/v1/url?k=efa2c314-b039fa16-efa3485b-0cc47a31381a-5dcf992b5d854429&q=1&e=1dac5900-a7aa-40ed-a2f0-9af17ae05bfe&u=https%3A%2F%2Flore.kernel.org%2Flinux-arm-kernel%2F20211122092816.2865873-8-ardb%40kernel.org%2F > > > > Cc: Marek Szyprowski <m.szyprowski@samsung.com> > > Cc: Geert Uytterhoeven <geert@linux-m68k.org> > > Cc: Jon Hunter <jonathanh@nvidia.com> > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > > This fixes the suspend/resume issue observed on ARM 32bit Exynos based > boards. Thanks! > > Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> > > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > Thanks Marek. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-01-06 19:26 ` [RFT PATCH] ARM: suspend: switch to swapper_pg_dir before using the vmap'ed stack Ard Biesheuvel
2022-01-07 9:14 ` Geert Uytterhoeven
2022-01-07 10:00 ` Ard Biesheuvel
2022-01-10 9:36 ` Marek Szyprowski
2022-01-10 10:55 ` Ard Biesheuvel
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