forked from Minki/linux
9ab3a15d95
Follows the powerpc change, for much the same rationale. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
191 lines
4.7 KiB
C
191 lines
4.7 KiB
C
/*
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* Alignment access counters and corresponding user-space interfaces.
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*
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* Copyright (C) 2009 ST Microelectronics
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* Copyright (C) 2009 - 2010 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/seq_file.h>
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#include <linux/proc_fs.h>
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#include <linux/uaccess.h>
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#include <linux/ratelimit.h>
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#include <asm/alignment.h>
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#include <asm/processor.h>
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static unsigned long se_user;
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static unsigned long se_sys;
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static unsigned long se_half;
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static unsigned long se_word;
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static unsigned long se_dword;
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static unsigned long se_multi;
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/* bitfield: 1: warn 2: fixup 4: signal -> combinations 2|4 && 1|2|4 are not
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valid! */
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static int se_usermode = UM_WARN | UM_FIXUP;
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/* 0: no warning 1: print a warning message, disabled by default */
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static int se_kernmode_warn;
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core_param(alignment, se_usermode, int, 0600);
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void inc_unaligned_byte_access(void)
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{
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se_half++;
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}
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void inc_unaligned_word_access(void)
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{
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se_word++;
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}
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void inc_unaligned_dword_access(void)
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{
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se_dword++;
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}
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void inc_unaligned_multi_access(void)
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{
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se_multi++;
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}
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void inc_unaligned_user_access(void)
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{
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se_user++;
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}
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void inc_unaligned_kernel_access(void)
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{
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se_sys++;
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}
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/*
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* This defaults to the global policy which can be set from the command
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* line, while processes can overload their preferences via prctl().
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*/
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unsigned int unaligned_user_action(void)
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{
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unsigned int action = se_usermode;
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if (current->thread.flags & SH_THREAD_UAC_SIGBUS) {
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action &= ~UM_FIXUP;
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action |= UM_SIGNAL;
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}
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if (current->thread.flags & SH_THREAD_UAC_NOPRINT)
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action &= ~UM_WARN;
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return action;
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}
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int get_unalign_ctl(struct task_struct *tsk, unsigned long addr)
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{
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return put_user(tsk->thread.flags & SH_THREAD_UAC_MASK,
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(unsigned int __user *)addr);
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}
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int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
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{
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tsk->thread.flags = (tsk->thread.flags & ~SH_THREAD_UAC_MASK) |
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(val & SH_THREAD_UAC_MASK);
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return 0;
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}
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void unaligned_fixups_notify(struct task_struct *tsk, insn_size_t insn,
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struct pt_regs *regs)
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{
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if (user_mode(regs) && (se_usermode & UM_WARN))
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pr_notice_ratelimited("Fixing up unaligned userspace access "
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"in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
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tsk->comm, task_pid_nr(tsk),
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(void *)instruction_pointer(regs), insn);
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else if (se_kernmode_warn)
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pr_notice_ratelimited("Fixing up unaligned kernel access "
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"in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
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tsk->comm, task_pid_nr(tsk),
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(void *)instruction_pointer(regs), insn);
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}
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static const char *se_usermode_action[] = {
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"ignored",
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"warn",
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"fixup",
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"fixup+warn",
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"signal",
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"signal+warn"
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};
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static int alignment_proc_show(struct seq_file *m, void *v)
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{
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seq_printf(m, "User:\t\t%lu\n", se_user);
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seq_printf(m, "System:\t\t%lu\n", se_sys);
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seq_printf(m, "Half:\t\t%lu\n", se_half);
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seq_printf(m, "Word:\t\t%lu\n", se_word);
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seq_printf(m, "DWord:\t\t%lu\n", se_dword);
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seq_printf(m, "Multi:\t\t%lu\n", se_multi);
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seq_printf(m, "User faults:\t%i (%s)\n", se_usermode,
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se_usermode_action[se_usermode]);
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seq_printf(m, "Kernel faults:\t%i (fixup%s)\n", se_kernmode_warn,
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se_kernmode_warn ? "+warn" : "");
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return 0;
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}
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static int alignment_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, alignment_proc_show, NULL);
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}
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static ssize_t alignment_proc_write(struct file *file,
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const char __user *buffer, size_t count, loff_t *pos)
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{
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int *data = PDE(file->f_path.dentry->d_inode)->data;
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char mode;
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if (count > 0) {
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if (get_user(mode, buffer))
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return -EFAULT;
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if (mode >= '0' && mode <= '5')
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*data = mode - '0';
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}
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return count;
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}
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static const struct file_operations alignment_proc_fops = {
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.owner = THIS_MODULE,
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.open = alignment_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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.write = alignment_proc_write,
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};
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/*
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* This needs to be done after sysctl_init, otherwise sys/ will be
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* overwritten. Actually, this shouldn't be in sys/ at all since
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* it isn't a sysctl, and it doesn't contain sysctl information.
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* We now locate it in /proc/cpu/alignment instead.
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*/
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static int __init alignment_init(void)
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{
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struct proc_dir_entry *dir, *res;
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dir = proc_mkdir("cpu", NULL);
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if (!dir)
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return -ENOMEM;
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res = proc_create_data("alignment", S_IWUSR | S_IRUGO, dir,
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&alignment_proc_fops, &se_usermode);
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if (!res)
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return -ENOMEM;
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res = proc_create_data("kernel_alignment", S_IWUSR | S_IRUGO, dir,
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&alignment_proc_fops, &se_kernmode_warn);
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if (!res)
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return -ENOMEM;
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return 0;
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}
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fs_initcall(alignment_init);
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