From a050ba1e7422f2cc60ff8bfde3f96d34d00cb585 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 24 Jun 2023 10:55:38 -0700 Subject: [PATCH] mm/fault: convert remaining simple cases to lock_mm_and_find_vma() This does the simple pattern conversion of alpha, arc, csky, hexagon, loongarch, nios2, sh, sparc32, and xtensa to the lock_mm_and_find_vma() helper. They all have the regular fault handling pattern without odd special cases. The remaining architectures all have something that keeps us from a straightforward conversion: ia64 and parisc have stacks that can grow both up as well as down (and ia64 has special address region checks). And m68k, microblaze, openrisc, sparc64, and um end up having extra rules about only expanding the stack down a limited amount below the user space stack pointer. That is something that x86 used to do too (long long ago), and it probably could just be skipped, but it still makes the conversion less than trivial. Note that this conversion was done manually and with the exception of alpha without any build testing, because I have a fairly limited cross- building environment. The cases are all simple, and I went through the changes several times, but... Signed-off-by: Linus Torvalds --- arch/alpha/Kconfig | 1 + arch/alpha/mm/fault.c | 13 +++---------- arch/arc/Kconfig | 1 + arch/arc/mm/fault.c | 11 +++-------- arch/csky/Kconfig | 1 + arch/csky/mm/fault.c | 22 +++++----------------- arch/hexagon/Kconfig | 1 + arch/hexagon/mm/vm_fault.c | 18 ++++-------------- arch/loongarch/Kconfig | 1 + arch/loongarch/mm/fault.c | 16 ++++++---------- arch/nios2/Kconfig | 1 + arch/nios2/mm/fault.c | 17 ++--------------- arch/sh/Kconfig | 1 + arch/sh/mm/fault.c | 17 ++--------------- arch/sparc/Kconfig | 1 + arch/sparc/mm/fault_32.c | 32 ++++++++------------------------ arch/xtensa/Kconfig | 1 + arch/xtensa/mm/fault.c | 14 +++----------- 18 files changed, 45 insertions(+), 124 deletions(-) diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index a5c2b1aa46b0..d6968d090d49 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -30,6 +30,7 @@ config ALPHA select HAS_IOPORT select HAVE_ARCH_AUDITSYSCALL select HAVE_MOD_ARCH_SPECIFIC + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select ODD_RT_SIGACTION select OLD_SIGSUSPEND diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c index 7b01ae4f3bc6..8c9850437e67 100644 --- a/arch/alpha/mm/fault.c +++ b/arch/alpha/mm/fault.c @@ -119,20 +119,12 @@ do_page_fault(unsigned long address, unsigned long mmcsr, flags |= FAULT_FLAG_USER; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); retry: - mmap_read_lock(mm); - vma = find_vma(mm, address); + vma = lock_mm_and_find_vma(mm, address, regs); if (!vma) - goto bad_area; - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, address)) - goto bad_area; + goto bad_area_nosemaphore; /* Ok, we have a good vm_area for this memory access, so we can handle it. */ - good_area: si_code = SEGV_ACCERR; if (cause < 0) { if (!(vma->vm_flags & VM_EXEC)) @@ -192,6 +184,7 @@ retry: bad_area: mmap_read_unlock(mm); + bad_area_nosemaphore: if (user_mode(regs)) goto do_sigsegv; diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index ab6d701365bb..96cf8720bb93 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -41,6 +41,7 @@ config ARC select HAVE_PERF_EVENTS select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select OF select OF_EARLY_FLATTREE diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c index 5ca59a482632..f59e722d147f 100644 --- a/arch/arc/mm/fault.c +++ b/arch/arc/mm/fault.c @@ -113,15 +113,9 @@ void do_page_fault(unsigned long address, struct pt_regs *regs) perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); retry: - mmap_read_lock(mm); - - vma = find_vma(mm, address); + vma = lock_mm_and_find_vma(mm, address, regs); if (!vma) - goto bad_area; - if (unlikely(address < vma->vm_start)) { - if (!(vma->vm_flags & VM_GROWSDOWN) || expand_stack(vma, address)) - goto bad_area; - } + goto bad_area_nosemaphore; /* * vm_area is good, now check permissions for this memory access @@ -161,6 +155,7 @@ retry: bad_area: mmap_read_unlock(mm); +bad_area_nosemaphore: /* * Major/minor page fault accounting * (in case of retry we only land here once) diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 4df1f8c9d170..03e9f6666157 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -96,6 +96,7 @@ config CSKY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS + select LOCK_MM_AND_FIND_VMA select MAY_HAVE_SPARSE_IRQ select MODULES_USE_ELF_RELA if MODULES select OF diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c index e15f736cca4b..ae9781b7d92e 100644 --- a/arch/csky/mm/fault.c +++ b/arch/csky/mm/fault.c @@ -97,13 +97,12 @@ static inline void mm_fault_error(struct pt_regs *regs, unsigned long addr, vm_f BUG(); } -static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code, unsigned long addr) +static inline void bad_area_nosemaphore(struct pt_regs *regs, struct mm_struct *mm, int code, unsigned long addr) { /* * Something tried to access memory that isn't in our memory map. * Fix it, but check if it's kernel or user first. */ - mmap_read_unlock(mm); /* User mode accesses just cause a SIGSEGV */ if (user_mode(regs)) { do_trap(regs, SIGSEGV, code, addr); @@ -238,20 +237,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs) if (is_write(regs)) flags |= FAULT_FLAG_WRITE; retry: - mmap_read_lock(mm); - vma = find_vma(mm, addr); + vma = lock_mm_and_find_vma(mm, address, regs); if (unlikely(!vma)) { - bad_area(regs, mm, code, addr); - return; - } - if (likely(vma->vm_start <= addr)) - goto good_area; - if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) { - bad_area(regs, mm, code, addr); - return; - } - if (unlikely(expand_stack(vma, addr))) { - bad_area(regs, mm, code, addr); + bad_area_nosemaphore(regs, mm, code, addr); return; } @@ -259,11 +247,11 @@ retry: * Ok, we have a good vm_area for this memory access, so * we can handle it. */ -good_area: code = SEGV_ACCERR; if (unlikely(access_error(regs, vma))) { - bad_area(regs, mm, code, addr); + mmap_read_unlock(mm); + bad_area_nosemaphore(regs, mm, code, addr); return; } diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig index 54eadf265178..6726f4941015 100644 --- a/arch/hexagon/Kconfig +++ b/arch/hexagon/Kconfig @@ -28,6 +28,7 @@ config HEXAGON select GENERIC_SMP_IDLE_THREAD select STACKTRACE_SUPPORT select GENERIC_CLOCKEVENTS_BROADCAST + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select GENERIC_CPU_DEVICES select ARCH_WANT_LD_ORPHAN_WARN diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c index 4b578d02fd01..7295ea3f8cc8 100644 --- a/arch/hexagon/mm/vm_fault.c +++ b/arch/hexagon/mm/vm_fault.c @@ -57,21 +57,10 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs) perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); retry: - mmap_read_lock(mm); - vma = find_vma(mm, address); - if (!vma) - goto bad_area; + vma = lock_mm_and_find_vma(mm, address, regs); + if (unlikely(!vma)) + goto bad_area_nosemaphore; - if (vma->vm_start <= address) - goto good_area; - - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - - if (expand_stack(vma, address)) - goto bad_area; - -good_area: /* Address space is OK. Now check access rights. */ si_code = SEGV_ACCERR; @@ -143,6 +132,7 @@ good_area: bad_area: mmap_read_unlock(mm); +bad_area_nosemaphore: if (user_mode(regs)) { force_sig_fault(SIGSEGV, si_code, (void __user *)address); return; diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index d38b066fc931..73519e13bbb3 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -130,6 +130,7 @@ config LOONGARCH select HAVE_VIRT_CPU_ACCOUNTING_GEN if !SMP select IRQ_FORCED_THREADING select IRQ_LOONGARCH_CPU + select LOCK_MM_AND_FIND_VMA select MMU_GATHER_MERGE_VMAS if MMU select MODULES_USE_ELF_RELA if MODULES select NEED_PER_CPU_EMBED_FIRST_CHUNK diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c index 449087bd589d..da5b6d518cdb 100644 --- a/arch/loongarch/mm/fault.c +++ b/arch/loongarch/mm/fault.c @@ -169,22 +169,18 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); retry: - mmap_read_lock(mm); - vma = find_vma(mm, address); - if (!vma) - goto bad_area; - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (!expand_stack(vma, address)) - goto good_area; + vma = lock_mm_and_find_vma(mm, address, regs); + if (unlikely(!vma)) + goto bad_area_nosemaphore; + goto good_area; + /* * Something tried to access memory that isn't in our memory map.. * Fix it, but check if it's kernel or user first.. */ bad_area: mmap_read_unlock(mm); +bad_area_nosemaphore: do_sigsegv(regs, write, address, si_code); return; diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig index e5936417d3cd..d54464021a61 100644 --- a/arch/nios2/Kconfig +++ b/arch/nios2/Kconfig @@ -16,6 +16,7 @@ config NIOS2 select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_KGDB select IRQ_DOMAIN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select OF select OF_EARLY_FLATTREE diff --git a/arch/nios2/mm/fault.c b/arch/nios2/mm/fault.c index ca64eccea551..e3fa9c15181d 100644 --- a/arch/nios2/mm/fault.c +++ b/arch/nios2/mm/fault.c @@ -86,27 +86,14 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); - if (!mmap_read_trylock(mm)) { - if (!user_mode(regs) && !search_exception_tables(regs->ea)) - goto bad_area_nosemaphore; retry: - mmap_read_lock(mm); - } - - vma = find_vma(mm, address); + vma = lock_mm_and_find_vma(mm, address, regs); if (!vma) - goto bad_area; - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, address)) - goto bad_area; + goto bad_area_nosemaphore; /* * Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: code = SEGV_ACCERR; switch (cause) { diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 9652d367fc37..393023d09245 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -59,6 +59,7 @@ config SUPERH select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select IRQ_FORCED_THREADING + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select NEED_SG_DMA_LENGTH select NO_DMA if !MMU && !DMA_COHERENT diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index acd2f5e50bfc..06e6b4952924 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c @@ -439,21 +439,9 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, } retry: - mmap_read_lock(mm); - - vma = find_vma(mm, address); + vma = lock_mm_and_find_vma(mm, address, regs); if (unlikely(!vma)) { - bad_area(regs, error_code, address); - return; - } - if (likely(vma->vm_start <= address)) - goto good_area; - if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) { - bad_area(regs, error_code, address); - return; - } - if (unlikely(expand_stack(vma, address))) { - bad_area(regs, error_code, address); + bad_area_nosemaphore(regs, error_code, address); return; } @@ -461,7 +449,6 @@ retry: * Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: if (unlikely(access_error(error_code, vma))) { bad_area_access_error(regs, error_code, address); return; diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index 8535e19062f6..8c196990558b 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -57,6 +57,7 @@ config SPARC32 select DMA_DIRECT_REMAP select GENERIC_ATOMIC64 select HAVE_UID16 + select LOCK_MM_AND_FIND_VMA select OLD_SIGACTION select ZONE_DMA diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c index 179295b14664..a3ccc0267bc2 100644 --- a/arch/sparc/mm/fault_32.c +++ b/arch/sparc/mm/fault_32.c @@ -143,28 +143,19 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write, if (pagefault_disabled() || !mm) goto no_context; + if (!from_user && address >= PAGE_OFFSET) + goto no_context; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); retry: - mmap_read_lock(mm); - - if (!from_user && address >= PAGE_OFFSET) - goto bad_area; - - vma = find_vma(mm, address); + vma = lock_mm_and_find_vma(mm, address, regs); if (!vma) - goto bad_area; - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, address)) - goto bad_area; + goto bad_area_nosemaphore; /* * Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: code = SEGV_ACCERR; if (write) { if (!(vma->vm_flags & VM_WRITE)) @@ -321,17 +312,9 @@ static void force_user_fault(unsigned long address, int write) code = SEGV_MAPERR; - mmap_read_lock(mm); - vma = find_vma(mm, address); + vma = lock_mm_and_find_vma(mm, address, regs); if (!vma) - goto bad_area; - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, address)) - goto bad_area; -good_area: + goto bad_area_nosemaphore; code = SEGV_ACCERR; if (write) { if (!(vma->vm_flags & VM_WRITE)) @@ -350,6 +333,7 @@ good_area: return; bad_area: mmap_read_unlock(mm); +bad_area_nosemaphore: __do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address); return; diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index 3c6e5471f025..2d0d6440b979 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -49,6 +49,7 @@ config XTENSA select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING_GEN select IRQ_DOMAIN + select LOCK_MM_AND_FIND_VMA select MODULES_USE_ELF_RELA select PERF_USE_VMALLOC select TRACE_IRQFLAGS_SUPPORT diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c index faf7cf35a0ee..d1eb8d6c5b82 100644 --- a/arch/xtensa/mm/fault.c +++ b/arch/xtensa/mm/fault.c @@ -130,23 +130,14 @@ void do_page_fault(struct pt_regs *regs) perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); retry: - mmap_read_lock(mm); - vma = find_vma(mm, address); - + vma = lock_mm_and_find_vma(mm, address, regs); if (!vma) - goto bad_area; - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, address)) - goto bad_area; + goto bad_area_nosemaphore; /* Ok, we have a good vm_area for this memory access, so * we can handle it.. */ -good_area: code = SEGV_ACCERR; if (is_write) { @@ -205,6 +196,7 @@ good_area: */ bad_area: mmap_read_unlock(mm); +bad_area_nosemaphore: if (user_mode(regs)) { force_sig_fault(SIGSEGV, code, (void *) address); return;