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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-04-27 16:01:44 +0200 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-04-27 16:01:43 +0200 |
commit | be5ec363e958982454ac9b3138b0e78c032e758d (patch) | |
tree | 044e5e1baa1e878538fcd4ec6b6e7d7c0f009203 /arch/s390/mm/fault.c | |
parent | 10c1031f706bbe0690d84cdbccad15b11c6dc661 (diff) | |
download | op-kernel-dev-be5ec363e958982454ac9b3138b0e78c032e758d.zip op-kernel-dev-be5ec363e958982454ac9b3138b0e78c032e758d.tar.gz |
[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>
Diffstat (limited to 'arch/s390/mm/fault.c')
-rw-r--r-- | arch/s390/mm/fault.c | 72 |
1 files changed, 21 insertions, 51 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 8bc3518..2b76a87 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -26,9 +26,9 @@ #include <linux/module.h> #include <linux/hardirq.h> #include <linux/kprobes.h> +#include <linux/uaccess.h> #include <asm/system.h> -#include <asm/uaccess.h> #include <asm/pgtable.h> #include <asm/kdebug.h> #include <asm/s390_ext.h> @@ -263,68 +263,38 @@ 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) +static int signal_return(struct mm_struct *mm, struct pt_regs *regs, + unsigned long address, unsigned long error_code) { + u16 instruction; + int rc, compat; + + pagefault_disable(); + rc = __get_user(instruction, (u16 __user *) regs->psw.addr); + pagefault_enable(); + if (rc) + return -EFAULT; + 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); + compat = test_tsk_thread_flag(current, TIF_31BIT); + if (compat && instruction == 0x0a77) + sys32_sigreturn(regs); + else if (compat && instruction == 0x0aad) + sys32_rt_sigreturn(regs); else +#endif + if (instruction == 0x0a77) 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 if (instruction == 0x0aad) + sys_rt_sigreturn(regs); 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 */ |