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Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/fault.c88
-rw-r--r--arch/s390/mm/init.c6
-rw-r--r--arch/s390/mm/vmem.c14
3 files changed, 96 insertions, 12 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 3382e29f34a..9ff143e8774 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -137,7 +137,9 @@ static int __check_access_register(struct pt_regs *regs, int error_code)
/*
* Check which address space the address belongs to.
- * Returns 1 for user space and 0 for kernel space.
+ * May return 1 or 2 for user space and 0 for kernel space.
+ * Returns 2 for user space in primary addressing mode with
+ * CONFIG_S390_EXEC_PROTECT on and kernel parameter noexec=on.
*/
static inline int check_user_space(struct pt_regs *regs, int error_code)
{
@@ -154,7 +156,7 @@ static inline int check_user_space(struct pt_regs *regs, int error_code)
return __check_access_register(regs, error_code);
if (descriptor == 2)
return current->thread.mm_segment.ar4;
- return descriptor != 0;
+ return ((descriptor != 0) ^ (switch_amode)) << s390_noexec;
}
/*
@@ -183,6 +185,77 @@ static void do_sigsegv(struct pt_regs *regs, unsigned long error_code,
force_sig_info(SIGSEGV, &si, current);
}
+#ifdef CONFIG_S390_EXEC_PROTECT
+extern long sys_sigreturn(struct pt_regs *regs);
+extern long sys_rt_sigreturn(struct pt_regs *regs);
+extern long sys32_sigreturn(struct pt_regs *regs);
+extern long sys32_rt_sigreturn(struct pt_regs *regs);
+
+static inline void do_sigreturn(struct mm_struct *mm, struct pt_regs *regs,
+ int rt)
+{
+ up_read(&mm->mmap_sem);
+ clear_tsk_thread_flag(current, TIF_SINGLE_STEP);
+#ifdef CONFIG_COMPAT
+ if (test_tsk_thread_flag(current, TIF_31BIT)) {
+ if (rt)
+ sys32_rt_sigreturn(regs);
+ else
+ sys32_sigreturn(regs);
+ return;
+ }
+#endif /* CONFIG_COMPAT */
+ if (rt)
+ sys_rt_sigreturn(regs);
+ else
+ sys_sigreturn(regs);
+ return;
+}
+
+static int signal_return(struct mm_struct *mm, struct pt_regs *regs,
+ unsigned long address, unsigned long error_code)
+{
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ u16 *instruction;
+ unsigned long pfn, uaddr = regs->psw.addr;
+
+ spin_lock(&mm->page_table_lock);
+ pgd = pgd_offset(mm, uaddr);
+ if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+ goto out_fault;
+ pmd = pmd_offset(pgd, uaddr);
+ if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+ goto out_fault;
+ pte = pte_offset_map(pmd_offset(pgd_offset(mm, uaddr), uaddr), uaddr);
+ if (!pte || !pte_present(*pte))
+ goto out_fault;
+ pfn = pte_pfn(*pte);
+ if (!pfn_valid(pfn))
+ goto out_fault;
+ spin_unlock(&mm->page_table_lock);
+
+ instruction = (u16 *) ((pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE-1)));
+ if (*instruction == 0x0a77)
+ do_sigreturn(mm, regs, 0);
+ else if (*instruction == 0x0aad)
+ do_sigreturn(mm, regs, 1);
+ else {
+ printk("- XXX - do_exception: task = %s, primary, NO EXEC "
+ "-> SIGSEGV\n", current->comm);
+ up_read(&mm->mmap_sem);
+ current->thread.prot_addr = address;
+ current->thread.trap_no = error_code;
+ do_sigsegv(regs, error_code, SEGV_MAPERR, address);
+ }
+ return 0;
+out_fault:
+ spin_unlock(&mm->page_table_lock);
+ return -EFAULT;
+}
+#endif /* CONFIG_S390_EXEC_PROTECT */
+
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
@@ -260,6 +333,17 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
+
+#ifdef CONFIG_S390_EXEC_PROTECT
+ if (unlikely((user_address == 2) && !(vma->vm_flags & VM_EXEC)))
+ if (!signal_return(mm, regs, address, error_code))
+ /*
+ * signal_return() has done an up_read(&mm->mmap_sem)
+ * if it returns 0.
+ */
+ return;
+#endif
+
if (vma->vm_start <= address)
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 0e7e9acab9e..162a338a557 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -104,7 +104,7 @@ static void __init setup_ro_region(void)
pmd = pmd_offset(pgd, address);
pte = pte_offset_kernel(pmd, address);
new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
- set_pte(pte, new_pte);
+ *pte = new_pte;
}
}
@@ -124,11 +124,11 @@ void __init paging_init(void)
#ifdef CONFIG_64BIT
pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
for (i = 0; i < PTRS_PER_PGD; i++)
- pgd_clear(pg_dir + i);
+ pgd_clear_kernel(pg_dir + i);
#else
pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
for (i = 0; i < PTRS_PER_PGD; i++)
- pmd_clear((pmd_t *)(pg_dir + i));
+ pmd_clear_kernel((pmd_t *)(pg_dir + i));
#endif
vmem_map_init();
setup_ro_region();
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index cd3d93e8c21..92a56519002 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -82,7 +82,7 @@ static inline pmd_t *vmem_pmd_alloc(void)
if (!pmd)
return NULL;
for (i = 0; i < PTRS_PER_PMD; i++)
- pmd_clear(pmd + i);
+ pmd_clear_kernel(pmd + i);
return pmd;
}
@@ -97,7 +97,7 @@ static inline pte_t *vmem_pte_alloc(void)
return NULL;
pte_val(empty_pte) = _PAGE_TYPE_EMPTY;
for (i = 0; i < PTRS_PER_PTE; i++)
- set_pte(pte + i, empty_pte);
+ pte[i] = empty_pte;
return pte;
}
@@ -119,7 +119,7 @@ static int vmem_add_range(unsigned long start, unsigned long size)
pm_dir = vmem_pmd_alloc();
if (!pm_dir)
goto out;
- pgd_populate(&init_mm, pg_dir, pm_dir);
+ pgd_populate_kernel(&init_mm, pg_dir, pm_dir);
}
pm_dir = pmd_offset(pg_dir, address);
@@ -132,7 +132,7 @@ static int vmem_add_range(unsigned long start, unsigned long size)
pt_dir = pte_offset_kernel(pm_dir, address);
pte = pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL);
- set_pte(pt_dir, pte);
+ *pt_dir = pte;
}
ret = 0;
out:
@@ -161,7 +161,7 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
if (pmd_none(*pm_dir))
continue;
pt_dir = pte_offset_kernel(pm_dir, address);
- set_pte(pt_dir, pte);
+ *pt_dir = pte;
}
flush_tlb_kernel_range(start, start + size);
}
@@ -191,7 +191,7 @@ static int vmem_add_mem_map(unsigned long start, unsigned long size)
pm_dir = vmem_pmd_alloc();
if (!pm_dir)
goto out;
- pgd_populate(&init_mm, pg_dir, pm_dir);
+ pgd_populate_kernel(&init_mm, pg_dir, pm_dir);
}
pm_dir = pmd_offset(pg_dir, address);
@@ -210,7 +210,7 @@ static int vmem_add_mem_map(unsigned long start, unsigned long size)
if (!new_page)
goto out;
pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
- set_pte(pt_dir, pte);
+ *pt_dir = pte;
}
}
ret = 0;
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-11 01:52:18 +0000