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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/um/kernel/tlb.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/um/kernel/tlb.c')
-rw-r--r-- | arch/um/kernel/tlb.c | 602 |
1 files changed, 602 insertions, 0 deletions
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c new file mode 100644 index 000000000..ad449173a --- /dev/null +++ b/arch/um/kernel/tlb.c @@ -0,0 +1,602 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/sched/signal.h> + +#include <asm/tlbflush.h> +#include <as-layout.h> +#include <mem_user.h> +#include <os.h> +#include <skas.h> +#include <kern_util.h> + +struct host_vm_change { + struct host_vm_op { + enum { NONE, MMAP, MUNMAP, MPROTECT } type; + union { + struct { + unsigned long addr; + unsigned long len; + unsigned int prot; + int fd; + __u64 offset; + } mmap; + struct { + unsigned long addr; + unsigned long len; + } munmap; + struct { + unsigned long addr; + unsigned long len; + unsigned int prot; + } mprotect; + } u; + } ops[1]; + int userspace; + int index; + struct mm_struct *mm; + void *data; + int force; +}; + +#define INIT_HVC(mm, force, userspace) \ + ((struct host_vm_change) \ + { .ops = { { .type = NONE } }, \ + .mm = mm, \ + .data = NULL, \ + .userspace = userspace, \ + .index = 0, \ + .force = force }) + +static void report_enomem(void) +{ + printk(KERN_ERR "UML ran out of memory on the host side! " + "This can happen due to a memory limitation or " + "vm.max_map_count has been reached.\n"); +} + +static int do_ops(struct host_vm_change *hvc, int end, + int finished) +{ + struct host_vm_op *op; + int i, ret = 0; + + for (i = 0; i < end && !ret; i++) { + op = &hvc->ops[i]; + switch (op->type) { + case MMAP: + if (hvc->userspace) + ret = map(&hvc->mm->context.id, op->u.mmap.addr, + op->u.mmap.len, op->u.mmap.prot, + op->u.mmap.fd, + op->u.mmap.offset, finished, + &hvc->data); + else + map_memory(op->u.mmap.addr, op->u.mmap.offset, + op->u.mmap.len, 1, 1, 1); + break; + case MUNMAP: + if (hvc->userspace) + ret = unmap(&hvc->mm->context.id, + op->u.munmap.addr, + op->u.munmap.len, finished, + &hvc->data); + else + ret = os_unmap_memory( + (void *) op->u.munmap.addr, + op->u.munmap.len); + + break; + case MPROTECT: + if (hvc->userspace) + ret = protect(&hvc->mm->context.id, + op->u.mprotect.addr, + op->u.mprotect.len, + op->u.mprotect.prot, + finished, &hvc->data); + else + ret = os_protect_memory( + (void *) op->u.mprotect.addr, + op->u.mprotect.len, + 1, 1, 1); + break; + default: + printk(KERN_ERR "Unknown op type %d in do_ops\n", + op->type); + BUG(); + break; + } + } + + if (ret == -ENOMEM) + report_enomem(); + + return ret; +} + +static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len, + unsigned int prot, struct host_vm_change *hvc) +{ + __u64 offset; + struct host_vm_op *last; + int fd = -1, ret = 0; + + if (hvc->userspace) + fd = phys_mapping(phys, &offset); + else + offset = phys; + if (hvc->index != 0) { + last = &hvc->ops[hvc->index - 1]; + if ((last->type == MMAP) && + (last->u.mmap.addr + last->u.mmap.len == virt) && + (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) && + (last->u.mmap.offset + last->u.mmap.len == offset)) { + last->u.mmap.len += len; + return 0; + } + } + + if (hvc->index == ARRAY_SIZE(hvc->ops)) { + ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0); + hvc->index = 0; + } + + hvc->ops[hvc->index++] = ((struct host_vm_op) + { .type = MMAP, + .u = { .mmap = { .addr = virt, + .len = len, + .prot = prot, + .fd = fd, + .offset = offset } + } }); + return ret; +} + +static int add_munmap(unsigned long addr, unsigned long len, + struct host_vm_change *hvc) +{ + struct host_vm_op *last; + int ret = 0; + + if (hvc->index != 0) { + last = &hvc->ops[hvc->index - 1]; + if ((last->type == MUNMAP) && + (last->u.munmap.addr + last->u.mmap.len == addr)) { + last->u.munmap.len += len; + return 0; + } + } + + if (hvc->index == ARRAY_SIZE(hvc->ops)) { + ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0); + hvc->index = 0; + } + + hvc->ops[hvc->index++] = ((struct host_vm_op) + { .type = MUNMAP, + .u = { .munmap = { .addr = addr, + .len = len } } }); + return ret; +} + +static int add_mprotect(unsigned long addr, unsigned long len, + unsigned int prot, struct host_vm_change *hvc) +{ + struct host_vm_op *last; + int ret = 0; + + if (hvc->index != 0) { + last = &hvc->ops[hvc->index - 1]; + if ((last->type == MPROTECT) && + (last->u.mprotect.addr + last->u.mprotect.len == addr) && + (last->u.mprotect.prot == prot)) { + last->u.mprotect.len += len; + return 0; + } + } + + if (hvc->index == ARRAY_SIZE(hvc->ops)) { + ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0); + hvc->index = 0; + } + + hvc->ops[hvc->index++] = ((struct host_vm_op) + { .type = MPROTECT, + .u = { .mprotect = { .addr = addr, + .len = len, + .prot = prot } } }); + return ret; +} + +#define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1)) + +static inline int update_pte_range(pmd_t *pmd, unsigned long addr, + unsigned long end, + struct host_vm_change *hvc) +{ + pte_t *pte; + int r, w, x, prot, ret = 0; + + pte = pte_offset_kernel(pmd, addr); + do { + r = pte_read(*pte); + w = pte_write(*pte); + x = pte_exec(*pte); + if (!pte_young(*pte)) { + r = 0; + w = 0; + } else if (!pte_dirty(*pte)) + w = 0; + + prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) | + (x ? UM_PROT_EXEC : 0)); + if (hvc->force || pte_newpage(*pte)) { + if (pte_present(*pte)) { + if (pte_newpage(*pte)) + ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK, + PAGE_SIZE, prot, hvc); + } else + ret = add_munmap(addr, PAGE_SIZE, hvc); + } else if (pte_newprot(*pte)) + ret = add_mprotect(addr, PAGE_SIZE, prot, hvc); + *pte = pte_mkuptodate(*pte); + } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret)); + return ret; +} + +static inline int update_pmd_range(pud_t *pud, unsigned long addr, + unsigned long end, + struct host_vm_change *hvc) +{ + pmd_t *pmd; + unsigned long next; + int ret = 0; + + pmd = pmd_offset(pud, addr); + do { + next = pmd_addr_end(addr, end); + if (!pmd_present(*pmd)) { + if (hvc->force || pmd_newpage(*pmd)) { + ret = add_munmap(addr, next - addr, hvc); + pmd_mkuptodate(*pmd); + } + } + else ret = update_pte_range(pmd, addr, next, hvc); + } while (pmd++, addr = next, ((addr < end) && !ret)); + return ret; +} + +static inline int update_pud_range(p4d_t *p4d, unsigned long addr, + unsigned long end, + struct host_vm_change *hvc) +{ + pud_t *pud; + unsigned long next; + int ret = 0; + + pud = pud_offset(p4d, addr); + do { + next = pud_addr_end(addr, end); + if (!pud_present(*pud)) { + if (hvc->force || pud_newpage(*pud)) { + ret = add_munmap(addr, next - addr, hvc); + pud_mkuptodate(*pud); + } + } + else ret = update_pmd_range(pud, addr, next, hvc); + } while (pud++, addr = next, ((addr < end) && !ret)); + return ret; +} + +static inline int update_p4d_range(pgd_t *pgd, unsigned long addr, + unsigned long end, + struct host_vm_change *hvc) +{ + p4d_t *p4d; + unsigned long next; + int ret = 0; + + p4d = p4d_offset(pgd, addr); + do { + next = p4d_addr_end(addr, end); + if (!p4d_present(*p4d)) { + if (hvc->force || p4d_newpage(*p4d)) { + ret = add_munmap(addr, next - addr, hvc); + p4d_mkuptodate(*p4d); + } + } else + ret = update_pud_range(p4d, addr, next, hvc); + } while (p4d++, addr = next, ((addr < end) && !ret)); + return ret; +} + +void fix_range_common(struct mm_struct *mm, unsigned long start_addr, + unsigned long end_addr, int force) +{ + pgd_t *pgd; + struct host_vm_change hvc; + unsigned long addr = start_addr, next; + int ret = 0, userspace = 1; + + hvc = INIT_HVC(mm, force, userspace); + pgd = pgd_offset(mm, addr); + do { + next = pgd_addr_end(addr, end_addr); + if (!pgd_present(*pgd)) { + if (force || pgd_newpage(*pgd)) { + ret = add_munmap(addr, next - addr, &hvc); + pgd_mkuptodate(*pgd); + } + } else + ret = update_p4d_range(pgd, addr, next, &hvc); + } while (pgd++, addr = next, ((addr < end_addr) && !ret)); + + if (!ret) + ret = do_ops(&hvc, hvc.index, 1); + + /* This is not an else because ret is modified above */ + if (ret) { + struct mm_id *mm_idp = ¤t->mm->context.id; + + printk(KERN_ERR "fix_range_common: failed, killing current " + "process: %d\n", task_tgid_vnr(current)); + mm_idp->kill = 1; + } +} + +static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end) +{ + struct mm_struct *mm; + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + unsigned long addr, last; + int updated = 0, err = 0, force = 0, userspace = 0; + struct host_vm_change hvc; + + mm = &init_mm; + hvc = INIT_HVC(mm, force, userspace); + for (addr = start; addr < end;) { + pgd = pgd_offset(mm, addr); + if (!pgd_present(*pgd)) { + last = ADD_ROUND(addr, PGDIR_SIZE); + if (last > end) + last = end; + if (pgd_newpage(*pgd)) { + updated = 1; + err = add_munmap(addr, last - addr, &hvc); + if (err < 0) + panic("munmap failed, errno = %d\n", + -err); + } + addr = last; + continue; + } + + p4d = p4d_offset(pgd, addr); + if (!p4d_present(*p4d)) { + last = ADD_ROUND(addr, P4D_SIZE); + if (last > end) + last = end; + if (p4d_newpage(*p4d)) { + updated = 1; + err = add_munmap(addr, last - addr, &hvc); + if (err < 0) + panic("munmap failed, errno = %d\n", + -err); + } + addr = last; + continue; + } + + pud = pud_offset(p4d, addr); + if (!pud_present(*pud)) { + last = ADD_ROUND(addr, PUD_SIZE); + if (last > end) + last = end; + if (pud_newpage(*pud)) { + updated = 1; + err = add_munmap(addr, last - addr, &hvc); + if (err < 0) + panic("munmap failed, errno = %d\n", + -err); + } + addr = last; + continue; + } + + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) { + last = ADD_ROUND(addr, PMD_SIZE); + if (last > end) + last = end; + if (pmd_newpage(*pmd)) { + updated = 1; + err = add_munmap(addr, last - addr, &hvc); + if (err < 0) + panic("munmap failed, errno = %d\n", + -err); + } + addr = last; + continue; + } + + pte = pte_offset_kernel(pmd, addr); + if (!pte_present(*pte) || pte_newpage(*pte)) { + updated = 1; + err = add_munmap(addr, PAGE_SIZE, &hvc); + if (err < 0) + panic("munmap failed, errno = %d\n", + -err); + if (pte_present(*pte)) + err = add_mmap(addr, pte_val(*pte) & PAGE_MASK, + PAGE_SIZE, 0, &hvc); + } + else if (pte_newprot(*pte)) { + updated = 1; + err = add_mprotect(addr, PAGE_SIZE, 0, &hvc); + } + addr += PAGE_SIZE; + } + if (!err) + err = do_ops(&hvc, hvc.index, 1); + + if (err < 0) + panic("flush_tlb_kernel failed, errno = %d\n", err); + return updated; +} + +void flush_tlb_page(struct vm_area_struct *vma, unsigned long address) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + struct mm_struct *mm = vma->vm_mm; + void *flush = NULL; + int r, w, x, prot, err = 0; + struct mm_id *mm_id; + + address &= PAGE_MASK; + + pgd = pgd_offset(mm, address); + if (!pgd_present(*pgd)) + goto kill; + + p4d = p4d_offset(pgd, address); + if (!p4d_present(*p4d)) + goto kill; + + pud = pud_offset(p4d, address); + if (!pud_present(*pud)) + goto kill; + + pmd = pmd_offset(pud, address); + if (!pmd_present(*pmd)) + goto kill; + + pte = pte_offset_kernel(pmd, address); + + r = pte_read(*pte); + w = pte_write(*pte); + x = pte_exec(*pte); + if (!pte_young(*pte)) { + r = 0; + w = 0; + } else if (!pte_dirty(*pte)) { + w = 0; + } + + mm_id = &mm->context.id; + prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) | + (x ? UM_PROT_EXEC : 0)); + if (pte_newpage(*pte)) { + if (pte_present(*pte)) { + unsigned long long offset; + int fd; + + fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset); + err = map(mm_id, address, PAGE_SIZE, prot, fd, offset, + 1, &flush); + } + else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush); + } + else if (pte_newprot(*pte)) + err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush); + + if (err) { + if (err == -ENOMEM) + report_enomem(); + + goto kill; + } + + *pte = pte_mkuptodate(*pte); + + return; + +kill: + printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address); + force_sig(SIGKILL); +} + +void flush_tlb_all(void) +{ + /* + * Don't bother flushing if this address space is about to be + * destroyed. + */ + if (atomic_read(¤t->mm->mm_users) == 0) + return; + + flush_tlb_mm(current->mm); +} + +void flush_tlb_kernel_range(unsigned long start, unsigned long end) +{ + flush_tlb_kernel_range_common(start, end); +} + +void flush_tlb_kernel_vm(void) +{ + flush_tlb_kernel_range_common(start_vm, end_vm); +} + +void __flush_tlb_one(unsigned long addr) +{ + flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE); +} + +static void fix_range(struct mm_struct *mm, unsigned long start_addr, + unsigned long end_addr, int force) +{ + /* + * Don't bother flushing if this address space is about to be + * destroyed. + */ + if (atomic_read(&mm->mm_users) == 0) + return; + + fix_range_common(mm, start_addr, end_addr, force); +} + +void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + if (vma->vm_mm == NULL) + flush_tlb_kernel_range_common(start, end); + else fix_range(vma->vm_mm, start, end, 0); +} +EXPORT_SYMBOL(flush_tlb_range); + +void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, + unsigned long end) +{ + fix_range(mm, start, end, 0); +} + +void flush_tlb_mm(struct mm_struct *mm) +{ + struct vm_area_struct *vma; + VMA_ITERATOR(vmi, mm, 0); + + for_each_vma(vmi, vma) + fix_range(mm, vma->vm_start, vma->vm_end, 0); +} + +void force_flush_all(void) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + VMA_ITERATOR(vmi, mm, 0); + + for_each_vma(vmi, vma) + fix_range(mm, vma->vm_start, vma->vm_end, 1); +} |