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[S390] No execute support cleanup.
Simplify the signal_return function that checks for the two special system calls sigreturn and rt_sigreturn. No need to do a page table walk, a call to copy_from_user while disabled page faults will work as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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parent
10c1031f70
commit
be5ec363e9
1 changed files with 22 additions and 52 deletions
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@ -26,9 +26,9 @@
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#include <linux/module.h>
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#include <linux/hardirq.h>
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#include <linux/kprobes.h>
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#include <linux/uaccess.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/kdebug.h>
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#include <asm/s390_ext.h>
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@ -263,68 +263,38 @@ extern long sys_rt_sigreturn(struct pt_regs *regs);
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extern long sys32_sigreturn(struct pt_regs *regs);
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extern long sys32_rt_sigreturn(struct pt_regs *regs);
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static inline void do_sigreturn(struct mm_struct *mm, struct pt_regs *regs,
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int rt)
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{
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up_read(&mm->mmap_sem);
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clear_tsk_thread_flag(current, TIF_SINGLE_STEP);
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#ifdef CONFIG_COMPAT
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if (test_tsk_thread_flag(current, TIF_31BIT)) {
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if (rt)
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sys32_rt_sigreturn(regs);
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else
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sys32_sigreturn(regs);
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return;
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}
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#endif /* CONFIG_COMPAT */
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if (rt)
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sys_rt_sigreturn(regs);
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else
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sys_sigreturn(regs);
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return;
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}
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static int signal_return(struct mm_struct *mm, struct pt_regs *regs,
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unsigned long address, unsigned long error_code)
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{
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pgd_t *pgd;
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pmd_t *pmd;
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pte_t *pte;
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u16 *instruction;
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unsigned long pfn, uaddr = regs->psw.addr;
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u16 instruction;
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int rc, compat;
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spin_lock(&mm->page_table_lock);
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pgd = pgd_offset(mm, uaddr);
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if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
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goto out_fault;
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pmd = pmd_offset(pgd, uaddr);
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if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
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goto out_fault;
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pte = pte_offset_map(pmd_offset(pgd_offset(mm, uaddr), uaddr), uaddr);
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if (!pte || !pte_present(*pte))
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goto out_fault;
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pfn = pte_pfn(*pte);
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if (!pfn_valid(pfn))
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goto out_fault;
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spin_unlock(&mm->page_table_lock);
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pagefault_disable();
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rc = __get_user(instruction, (u16 __user *) regs->psw.addr);
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pagefault_enable();
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if (rc)
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return -EFAULT;
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instruction = (u16 *) ((pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE-1)));
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if (*instruction == 0x0a77)
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do_sigreturn(mm, regs, 0);
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else if (*instruction == 0x0aad)
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do_sigreturn(mm, regs, 1);
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up_read(&mm->mmap_sem);
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clear_tsk_thread_flag(current, TIF_SINGLE_STEP);
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#ifdef CONFIG_COMPAT
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compat = test_tsk_thread_flag(current, TIF_31BIT);
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if (compat && instruction == 0x0a77)
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sys32_sigreturn(regs);
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else if (compat && instruction == 0x0aad)
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sys32_rt_sigreturn(regs);
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else
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#endif
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if (instruction == 0x0a77)
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sys_sigreturn(regs);
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else if (instruction == 0x0aad)
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sys_rt_sigreturn(regs);
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else {
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printk("- XXX - do_exception: task = %s, primary, NO EXEC "
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"-> SIGSEGV\n", current->comm);
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up_read(&mm->mmap_sem);
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current->thread.prot_addr = address;
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current->thread.trap_no = error_code;
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do_sigsegv(regs, error_code, SEGV_MAPERR, address);
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}
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return 0;
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out_fault:
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spin_unlock(&mm->page_table_lock);
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return -EFAULT;
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}
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#endif /* CONFIG_S390_EXEC_PROTECT */
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