From a7c3acca53801e10a77ede6b759a73f5ac4bc261 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Wed, 21 Jul 2021 09:18:35 +0200 Subject: [PATCH 1/2] arm64: smccc: Save lr before calling __arm_smccc_sve_check() Commit cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint") added a call to __arm_smccc_sve_check() which clobbers the lr (register x30), causing __arm_smccc_hvc() to return to itself and crash. Save lr on the stack before calling __arm_smccc_sve_check(). Save the frame pointer (x29) to complete the frame record, and adjust the offsets used to access stack parameters. Acked-by: Ard Biesheuvel Acked-by: Mark Brown Fixes: cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint") Signed-off-by: Jean-Philippe Brucker Link: https://lore.kernel.org/r/20210721071834.69130-1-jean-philippe@linaro.org Signed-off-by: Will Deacon --- arch/arm64/kernel/smccc-call.S | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S index d3d37f932b97..487381164ff6 100644 --- a/arch/arm64/kernel/smccc-call.S +++ b/arch/arm64/kernel/smccc-call.S @@ -32,20 +32,23 @@ SYM_FUNC_END(__arm_smccc_sve_check) EXPORT_SYMBOL(__arm_smccc_sve_check) .macro SMCCC instr + stp x29, x30, [sp, #-16]! + mov x29, sp alternative_if ARM64_SVE bl __arm_smccc_sve_check alternative_else_nop_endif \instr #0 - ldr x4, [sp] + ldr x4, [sp, #16] stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS] stp x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS] - ldr x4, [sp, #8] + ldr x4, [sp, #24] cbz x4, 1f /* no quirk structure */ ldr x9, [x4, #ARM_SMCCC_QUIRK_ID_OFFS] cmp x9, #ARM_SMCCC_QUIRK_QCOM_A6 b.ne 1f str x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS] -1: ret +1: ldp x29, x30, [sp], #16 + ret .endm /* From d8a719059b9dc963aa190598778ac804ff3e6a87 Mon Sep 17 00:00:00 2001 From: Jonathan Marek Date: Wed, 21 Jul 2021 17:02:13 +1000 Subject: [PATCH 2/2] Revert "mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge" This reverts commit c742199a014de23ee92055c2473d91fe5561ffdf. c742199a014d ("mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge") breaks arm64 in at least two ways for configurations where PUD or PMD folding occur: 1. We no longer install huge-vmap mappings and silently fall back to page-granular entries, despite being able to install block entries at what is effectively the PGD level. 2. If the linear map is backed with block mappings, these will now silently fail to be created in alloc_init_pud(), causing a panic early during boot. The pgtable selftests caught this, although a fix has not been forthcoming and Christophe is AWOL at the moment, so just revert the change for now to get a working -rc3 on which we can queue patches for 5.15. A simple revert breaks the build for 32-bit PowerPC 8xx machines, which rely on the default function definitions when the corresponding page-table levels are folded, since commit a6a8f7c4aa7e ("powerpc/8xx: add support for huge pages on VMAP and VMALLOC"), eg: powerpc64-linux-ld: mm/vmalloc.o: in function `vunmap_pud_range': linux/mm/vmalloc.c:362: undefined reference to `pud_clear_huge' To avoid that, add stubs for pud_clear_huge() and pmd_clear_huge() in arch/powerpc/mm/nohash/8xx.c as suggested by Christophe. Cc: Christophe Leroy Cc: Catalin Marinas Cc: Andrew Morton Cc: Nicholas Piggin Cc: Mike Rapoport Cc: Mark Rutland Cc: Geert Uytterhoeven Fixes: c742199a014d ("mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge") Signed-off-by: Jonathan Marek Reviewed-by: Ard Biesheuvel Acked-by: Marc Zyngier [mpe: Fold in 8xx.c changes from Christophe and mention in change log] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/linux-arm-kernel/CAMuHMdXShORDox-xxaeUfDW3wx2PeggFSqhVSHVZNKCGK-y_vQ@mail.gmail.com/ Link: https://lore.kernel.org/r/20210717160118.9855-1-jonathan@marek.ca Link: https://lore.kernel.org/r/87r1fs1762.fsf@mpe.ellerman.id.au Signed-off-by: Will Deacon --- arch/arm64/mm/mmu.c | 20 ++++++++------------ arch/powerpc/mm/nohash/8xx.c | 10 ++++++++++ arch/x86/mm/pgtable.c | 34 +++++++++++++++------------------- include/linux/pgtable.h | 26 +------------------------- 4 files changed, 34 insertions(+), 56 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index d74586508448..9ff0de1b2b93 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1339,7 +1339,6 @@ void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) return dt_virt; } -#if CONFIG_PGTABLE_LEVELS > 3 int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) { pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot)); @@ -1354,16 +1353,6 @@ int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) return 1; } -int pud_clear_huge(pud_t *pudp) -{ - if (!pud_sect(READ_ONCE(*pudp))) - return 0; - pud_clear(pudp); - return 1; -} -#endif - -#if CONFIG_PGTABLE_LEVELS > 2 int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot) { pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), mk_pmd_sect_prot(prot)); @@ -1378,6 +1367,14 @@ int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot) return 1; } +int pud_clear_huge(pud_t *pudp) +{ + if (!pud_sect(READ_ONCE(*pudp))) + return 0; + pud_clear(pudp); + return 1; +} + int pmd_clear_huge(pmd_t *pmdp) { if (!pmd_sect(READ_ONCE(*pmdp))) @@ -1385,7 +1382,6 @@ int pmd_clear_huge(pmd_t *pmdp) pmd_clear(pmdp); return 1; } -#endif int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr) { diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c index 60780e089118..0df9fe29dd56 100644 --- a/arch/powerpc/mm/nohash/8xx.c +++ b/arch/powerpc/mm/nohash/8xx.c @@ -240,3 +240,13 @@ void __init setup_kuap(bool disabled) mtspr(SPRN_MD_AP, MD_APG_KUAP); } #endif + +int pud_clear_huge(pud_t *pud) +{ + return 0; +} + +int pmd_clear_huge(pmd_t *pmd) +{ + return 0; +} diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 3364fe62b903..3481b35cb4ec 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -682,7 +682,6 @@ int p4d_clear_huge(p4d_t *p4d) } #endif -#if CONFIG_PGTABLE_LEVELS > 3 /** * pud_set_huge - setup kernel PUD mapping * @@ -721,23 +720,6 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) return 1; } -/** - * pud_clear_huge - clear kernel PUD mapping when it is set - * - * Returns 1 on success and 0 on failure (no PUD map is found). - */ -int pud_clear_huge(pud_t *pud) -{ - if (pud_large(*pud)) { - pud_clear(pud); - return 1; - } - - return 0; -} -#endif - -#if CONFIG_PGTABLE_LEVELS > 2 /** * pmd_set_huge - setup kernel PMD mapping * @@ -768,6 +750,21 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) return 1; } +/** + * pud_clear_huge - clear kernel PUD mapping when it is set + * + * Returns 1 on success and 0 on failure (no PUD map is found). + */ +int pud_clear_huge(pud_t *pud) +{ + if (pud_large(*pud)) { + pud_clear(pud); + return 1; + } + + return 0; +} + /** * pmd_clear_huge - clear kernel PMD mapping when it is set * @@ -782,7 +779,6 @@ int pmd_clear_huge(pmd_t *pmd) return 0; } -#endif #ifdef CONFIG_X86_64 /** diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index d147480cdefc..e24d2c992b11 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1397,34 +1397,10 @@ static inline int p4d_clear_huge(p4d_t *p4d) } #endif /* !__PAGETABLE_P4D_FOLDED */ -#ifndef __PAGETABLE_PUD_FOLDED int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot); -int pud_clear_huge(pud_t *pud); -#else -static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) -{ - return 0; -} -static inline int pud_clear_huge(pud_t *pud) -{ - return 0; -} -#endif /* !__PAGETABLE_PUD_FOLDED */ - -#ifndef __PAGETABLE_PMD_FOLDED int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot); +int pud_clear_huge(pud_t *pud); int pmd_clear_huge(pmd_t *pmd); -#else -static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) -{ - return 0; -} -static inline int pmd_clear_huge(pmd_t *pmd) -{ - return 0; -} -#endif /* !__PAGETABLE_PMD_FOLDED */ - int p4d_free_pud_page(p4d_t *p4d, unsigned long addr); int pud_free_pmd_page(pud_t *pud, unsigned long addr); int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);