^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <asm/pgalloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <asm/sections.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <as-layout.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <skas.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) unsigned long kernel)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) pgd_t *pgd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) p4d_t *p4d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) pud_t *pud;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) pmd_t *pmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) pte_t *pte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) pgd = pgd_offset(mm, proc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) p4d = p4d_alloc(mm, pgd, proc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) if (!p4d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) pud = pud_alloc(mm, p4d, proc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) if (!pud)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) goto out_pud;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) pmd = pmd_alloc(mm, pud, proc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) if (!pmd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) goto out_pmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) pte = pte_alloc_map(mm, pmd, proc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) if (!pte)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) goto out_pte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) *pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) *pte = pte_mkread(*pte);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) out_pte:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) pmd_free(mm, pmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) out_pmd:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) pud_free(mm, pud);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) out_pud:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) p4d_free(mm, p4d);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) int init_new_context(struct task_struct *task, struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) struct mm_context *from_mm = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) struct mm_context *to_mm = &mm->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) unsigned long stack = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) int ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) stack = get_zeroed_page(GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) if (stack == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) to_mm->id.stack = stack;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) if (current->mm != NULL && current->mm != &init_mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) from_mm = ¤t->mm->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) block_signals_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (from_mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) to_mm->id.u.pid = copy_context_skas0(stack,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) from_mm->id.u.pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) else to_mm->id.u.pid = start_userspace(stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) unblock_signals_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (to_mm->id.u.pid < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) ret = to_mm->id.u.pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) ret = init_new_ldt(to_mm, from_mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) printk(KERN_ERR "init_new_context_skas - init_ldt"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) " failed, errno = %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) out_free:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) if (to_mm->id.stack != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) free_page(to_mm->id.stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) void uml_setup_stubs(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) int err, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) ret = init_stub_pte(mm, STUB_CODE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) (unsigned long) __syscall_stub_start);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) ret = init_stub_pte(mm, STUB_DATA, mm->context.id.stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) mm->context.stub_pages[0] = virt_to_page(__syscall_stub_start);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) mm->context.stub_pages[1] = virt_to_page(mm->context.id.stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) /* dup_mmap already holds mmap_lock */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) VM_READ | VM_MAYREAD | VM_EXEC |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) VM_MAYEXEC | VM_DONTCOPY | VM_PFNMAP,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) mm->context.stub_pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) printk(KERN_ERR "install_special_mapping returned %d\n", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) force_sigsegv(SIGSEGV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) void arch_exit_mmap(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) pte_t *pte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) pte = virt_to_pte(mm, STUB_CODE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) if (pte != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) pte_clear(mm, STUB_CODE, pte);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) pte = virt_to_pte(mm, STUB_DATA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) if (pte == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) pte_clear(mm, STUB_DATA, pte);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) void destroy_context(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) struct mm_context *mmu = &mm->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) * If init_new_context wasn't called, this will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * zero, resulting in a kill(0), which will result in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) * whole UML suddenly dying. Also, cover negative and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) * 1 cases, since they shouldn't happen either.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) if (mmu->id.u.pid < 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) printk(KERN_ERR "corrupt mm_context - pid = %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) mmu->id.u.pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) os_kill_ptraced_process(mmu->id.u.pid, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) free_page(mmu->id.stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) free_ldt(mmu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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