549 lines
15 KiB
C
549 lines
15 KiB
C
/* $Id: unaligned.c,v 1.23 2001/12/21 00:54:31 davem Exp $
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* unaligned.c: Unaligned load/store trap handling with special
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* cases for the kernel to do them more quickly.
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*
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* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
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* Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <asm/ptrace.h>
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#include <asm/processor.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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/* #define DEBUG_MNA */
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enum direction {
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load, /* ld, ldd, ldh, ldsh */
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store, /* st, std, sth, stsh */
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both, /* Swap, ldstub, etc. */
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fpload,
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fpstore,
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invalid,
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};
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#ifdef DEBUG_MNA
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static char *dirstrings[] = {
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"load", "store", "both", "fpload", "fpstore", "invalid"
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};
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#endif
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static inline enum direction decode_direction(unsigned int insn)
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{
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unsigned long tmp = (insn >> 21) & 1;
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if(!tmp)
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return load;
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else {
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if(((insn>>19)&0x3f) == 15)
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return both;
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else
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return store;
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}
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}
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/* 8 = double-word, 4 = word, 2 = half-word */
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static inline int decode_access_size(unsigned int insn)
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{
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insn = (insn >> 19) & 3;
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if(!insn)
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return 4;
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else if(insn == 3)
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return 8;
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else if(insn == 2)
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return 2;
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else {
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printk("Impossible unaligned trap. insn=%08x\n", insn);
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die_if_kernel("Byte sized unaligned access?!?!", current->thread.kregs);
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return 4; /* just to keep gcc happy. */
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}
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}
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/* 0x400000 = signed, 0 = unsigned */
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static inline int decode_signedness(unsigned int insn)
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{
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return (insn & 0x400000);
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}
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static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
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unsigned int rd)
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{
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if(rs2 >= 16 || rs1 >= 16 || rd >= 16) {
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/* Wheee... */
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__asm__ __volatile__("save %sp, -0x40, %sp\n\t"
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"save %sp, -0x40, %sp\n\t"
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"save %sp, -0x40, %sp\n\t"
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"save %sp, -0x40, %sp\n\t"
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"save %sp, -0x40, %sp\n\t"
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"save %sp, -0x40, %sp\n\t"
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"save %sp, -0x40, %sp\n\t"
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"restore; restore; restore; restore;\n\t"
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"restore; restore; restore;\n\t");
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}
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}
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static inline int sign_extend_imm13(int imm)
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{
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return imm << 19 >> 19;
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}
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static inline unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
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{
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struct reg_window *win;
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if(reg < 16)
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return (!reg ? 0 : regs->u_regs[reg]);
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/* Ho hum, the slightly complicated case. */
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win = (struct reg_window *) regs->u_regs[UREG_FP];
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return win->locals[reg - 16]; /* yes, I know what this does... */
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}
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static inline unsigned long safe_fetch_reg(unsigned int reg, struct pt_regs *regs)
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{
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struct reg_window __user *win;
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unsigned long ret;
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if (reg < 16)
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return (!reg ? 0 : regs->u_regs[reg]);
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/* Ho hum, the slightly complicated case. */
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win = (struct reg_window __user *) regs->u_regs[UREG_FP];
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if ((unsigned long)win & 3)
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return -1;
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if (get_user(ret, &win->locals[reg - 16]))
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return -1;
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return ret;
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}
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static inline unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
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{
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struct reg_window *win;
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if(reg < 16)
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return ®s->u_regs[reg];
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win = (struct reg_window *) regs->u_regs[UREG_FP];
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return &win->locals[reg - 16];
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}
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static unsigned long compute_effective_address(struct pt_regs *regs,
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unsigned int insn)
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{
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unsigned int rs1 = (insn >> 14) & 0x1f;
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unsigned int rs2 = insn & 0x1f;
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unsigned int rd = (insn >> 25) & 0x1f;
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if(insn & 0x2000) {
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maybe_flush_windows(rs1, 0, rd);
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return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
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} else {
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maybe_flush_windows(rs1, rs2, rd);
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return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
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}
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}
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unsigned long safe_compute_effective_address(struct pt_regs *regs,
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unsigned int insn)
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{
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unsigned int rs1 = (insn >> 14) & 0x1f;
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unsigned int rs2 = insn & 0x1f;
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unsigned int rd = (insn >> 25) & 0x1f;
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if(insn & 0x2000) {
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maybe_flush_windows(rs1, 0, rd);
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return (safe_fetch_reg(rs1, regs) + sign_extend_imm13(insn));
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} else {
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maybe_flush_windows(rs1, rs2, rd);
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return (safe_fetch_reg(rs1, regs) + safe_fetch_reg(rs2, regs));
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}
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}
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/* This is just to make gcc think panic does return... */
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static void unaligned_panic(char *str)
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{
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panic(str);
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}
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#define do_integer_load(dest_reg, size, saddr, is_signed, errh) ({ \
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__asm__ __volatile__ ( \
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"cmp %1, 8\n\t" \
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"be 9f\n\t" \
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" cmp %1, 4\n\t" \
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"be 6f\n" \
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"4:\t" " ldub [%2], %%l1\n" \
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"5:\t" "ldub [%2 + 1], %%l2\n\t" \
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"sll %%l1, 8, %%l1\n\t" \
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"tst %3\n\t" \
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"be 3f\n\t" \
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" add %%l1, %%l2, %%l1\n\t" \
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"sll %%l1, 16, %%l1\n\t" \
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"sra %%l1, 16, %%l1\n" \
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"3:\t" "b 0f\n\t" \
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" st %%l1, [%0]\n" \
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"6:\t" "ldub [%2 + 1], %%l2\n\t" \
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"sll %%l1, 24, %%l1\n" \
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"7:\t" "ldub [%2 + 2], %%g7\n\t" \
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"sll %%l2, 16, %%l2\n" \
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"8:\t" "ldub [%2 + 3], %%g1\n\t" \
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"sll %%g7, 8, %%g7\n\t" \
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"or %%l1, %%l2, %%l1\n\t" \
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"or %%g7, %%g1, %%g7\n\t" \
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"or %%l1, %%g7, %%l1\n\t" \
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"b 0f\n\t" \
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" st %%l1, [%0]\n" \
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"9:\t" "ldub [%2], %%l1\n" \
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"10:\t" "ldub [%2 + 1], %%l2\n\t" \
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"sll %%l1, 24, %%l1\n" \
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"11:\t" "ldub [%2 + 2], %%g7\n\t" \
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"sll %%l2, 16, %%l2\n" \
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"12:\t" "ldub [%2 + 3], %%g1\n\t" \
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"sll %%g7, 8, %%g7\n\t" \
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"or %%l1, %%l2, %%l1\n\t" \
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"or %%g7, %%g1, %%g7\n\t" \
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"or %%l1, %%g7, %%g7\n" \
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"13:\t" "ldub [%2 + 4], %%l1\n\t" \
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"st %%g7, [%0]\n" \
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"14:\t" "ldub [%2 + 5], %%l2\n\t" \
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"sll %%l1, 24, %%l1\n" \
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"15:\t" "ldub [%2 + 6], %%g7\n\t" \
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"sll %%l2, 16, %%l2\n" \
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"16:\t" "ldub [%2 + 7], %%g1\n\t" \
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"sll %%g7, 8, %%g7\n\t" \
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"or %%l1, %%l2, %%l1\n\t" \
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"or %%g7, %%g1, %%g7\n\t" \
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"or %%l1, %%g7, %%g7\n\t" \
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"st %%g7, [%0 + 4]\n" \
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"0:\n\n\t" \
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".section __ex_table,#alloc\n\t" \
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".word 4b, " #errh "\n\t" \
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".word 5b, " #errh "\n\t" \
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".word 6b, " #errh "\n\t" \
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".word 7b, " #errh "\n\t" \
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".word 8b, " #errh "\n\t" \
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".word 9b, " #errh "\n\t" \
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".word 10b, " #errh "\n\t" \
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".word 11b, " #errh "\n\t" \
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".word 12b, " #errh "\n\t" \
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".word 13b, " #errh "\n\t" \
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".word 14b, " #errh "\n\t" \
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".word 15b, " #errh "\n\t" \
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".word 16b, " #errh "\n\n\t" \
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".previous\n\t" \
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: : "r" (dest_reg), "r" (size), "r" (saddr), "r" (is_signed) \
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: "l1", "l2", "g7", "g1", "cc"); \
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})
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#define store_common(dst_addr, size, src_val, errh) ({ \
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__asm__ __volatile__ ( \
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"ld [%2], %%l1\n" \
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"cmp %1, 2\n\t" \
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"be 2f\n\t" \
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" cmp %1, 4\n\t" \
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"be 1f\n\t" \
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" srl %%l1, 24, %%l2\n\t" \
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"srl %%l1, 16, %%g7\n" \
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"4:\t" "stb %%l2, [%0]\n\t" \
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"srl %%l1, 8, %%l2\n" \
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"5:\t" "stb %%g7, [%0 + 1]\n\t" \
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"ld [%2 + 4], %%g7\n" \
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"6:\t" "stb %%l2, [%0 + 2]\n\t" \
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"srl %%g7, 24, %%l2\n" \
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"7:\t" "stb %%l1, [%0 + 3]\n\t" \
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"srl %%g7, 16, %%l1\n" \
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"8:\t" "stb %%l2, [%0 + 4]\n\t" \
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"srl %%g7, 8, %%l2\n" \
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"9:\t" "stb %%l1, [%0 + 5]\n" \
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"10:\t" "stb %%l2, [%0 + 6]\n\t" \
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"b 0f\n" \
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"11:\t" " stb %%g7, [%0 + 7]\n" \
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"1:\t" "srl %%l1, 16, %%g7\n" \
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"12:\t" "stb %%l2, [%0]\n\t" \
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"srl %%l1, 8, %%l2\n" \
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"13:\t" "stb %%g7, [%0 + 1]\n" \
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"14:\t" "stb %%l2, [%0 + 2]\n\t" \
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"b 0f\n" \
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"15:\t" " stb %%l1, [%0 + 3]\n" \
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"2:\t" "srl %%l1, 8, %%l2\n" \
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"16:\t" "stb %%l2, [%0]\n" \
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"17:\t" "stb %%l1, [%0 + 1]\n" \
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"0:\n\n\t" \
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".section __ex_table,#alloc\n\t" \
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".word 4b, " #errh "\n\t" \
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".word 5b, " #errh "\n\t" \
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".word 6b, " #errh "\n\t" \
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".word 7b, " #errh "\n\t" \
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".word 8b, " #errh "\n\t" \
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".word 9b, " #errh "\n\t" \
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".word 10b, " #errh "\n\t" \
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".word 11b, " #errh "\n\t" \
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".word 12b, " #errh "\n\t" \
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".word 13b, " #errh "\n\t" \
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".word 14b, " #errh "\n\t" \
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".word 15b, " #errh "\n\t" \
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".word 16b, " #errh "\n\t" \
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".word 17b, " #errh "\n\n\t" \
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".previous\n\t" \
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: : "r" (dst_addr), "r" (size), "r" (src_val) \
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: "l1", "l2", "g7", "g1", "cc"); \
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})
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#define do_integer_store(reg_num, size, dst_addr, regs, errh) ({ \
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unsigned long *src_val; \
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static unsigned long zero[2] = { 0, }; \
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\
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if (reg_num) src_val = fetch_reg_addr(reg_num, regs); \
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else { \
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src_val = &zero[0]; \
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if (size == 8) \
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zero[1] = fetch_reg(1, regs); \
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} \
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store_common(dst_addr, size, src_val, errh); \
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})
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extern void smp_capture(void);
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extern void smp_release(void);
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#define do_atomic(srcdest_reg, mem, errh) ({ \
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unsigned long flags, tmp; \
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\
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smp_capture(); \
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local_irq_save(flags); \
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tmp = *srcdest_reg; \
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do_integer_load(srcdest_reg, 4, mem, 0, errh); \
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store_common(mem, 4, &tmp, errh); \
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local_irq_restore(flags); \
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smp_release(); \
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})
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static inline void advance(struct pt_regs *regs)
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{
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regs->pc = regs->npc;
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regs->npc += 4;
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}
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static inline int floating_point_load_or_store_p(unsigned int insn)
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{
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return (insn >> 24) & 1;
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}
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static inline int ok_for_kernel(unsigned int insn)
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{
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return !floating_point_load_or_store_p(insn);
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}
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void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn) __asm__ ("kernel_mna_trap_fault");
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void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
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{
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unsigned long g2 = regs->u_regs [UREG_G2];
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unsigned long fixup = search_extables_range(regs->pc, &g2);
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if (!fixup) {
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unsigned long address = compute_effective_address(regs, insn);
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if(address < PAGE_SIZE) {
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printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference in mna handler");
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} else
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printk(KERN_ALERT "Unable to handle kernel paging request in mna handler");
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printk(KERN_ALERT " at virtual address %08lx\n",address);
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printk(KERN_ALERT "current->{mm,active_mm}->context = %08lx\n",
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(current->mm ? current->mm->context :
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current->active_mm->context));
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printk(KERN_ALERT "current->{mm,active_mm}->pgd = %08lx\n",
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(current->mm ? (unsigned long) current->mm->pgd :
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(unsigned long) current->active_mm->pgd));
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die_if_kernel("Oops", regs);
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/* Not reached */
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}
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regs->pc = fixup;
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regs->npc = regs->pc + 4;
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regs->u_regs [UREG_G2] = g2;
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}
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asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
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{
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enum direction dir = decode_direction(insn);
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int size = decode_access_size(insn);
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if(!ok_for_kernel(insn) || dir == both) {
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printk("Unsupported unaligned load/store trap for kernel at <%08lx>.\n",
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regs->pc);
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unaligned_panic("Wheee. Kernel does fpu/atomic unaligned load/store.");
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__asm__ __volatile__ ("\n"
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"kernel_unaligned_trap_fault:\n\t"
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"mov %0, %%o0\n\t"
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"call kernel_mna_trap_fault\n\t"
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" mov %1, %%o1\n\t"
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:
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: "r" (regs), "r" (insn)
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: "o0", "o1", "o2", "o3", "o4", "o5", "o7",
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"g1", "g2", "g3", "g4", "g5", "g7", "cc");
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} else {
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unsigned long addr = compute_effective_address(regs, insn);
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#ifdef DEBUG_MNA
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printk("KMNA: pc=%08lx [dir=%s addr=%08lx size=%d] retpc[%08lx]\n",
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regs->pc, dirstrings[dir], addr, size, regs->u_regs[UREG_RETPC]);
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#endif
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switch(dir) {
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case load:
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do_integer_load(fetch_reg_addr(((insn>>25)&0x1f), regs),
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size, (unsigned long *) addr,
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decode_signedness(insn),
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kernel_unaligned_trap_fault);
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break;
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case store:
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do_integer_store(((insn>>25)&0x1f), size,
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(unsigned long *) addr, regs,
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kernel_unaligned_trap_fault);
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break;
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#if 0 /* unsupported */
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case both:
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do_atomic(fetch_reg_addr(((insn>>25)&0x1f), regs),
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(unsigned long *) addr,
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kernel_unaligned_trap_fault);
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break;
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#endif
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default:
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panic("Impossible kernel unaligned trap.");
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/* Not reached... */
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}
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advance(regs);
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}
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}
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static inline int ok_for_user(struct pt_regs *regs, unsigned int insn,
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enum direction dir)
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{
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unsigned int reg;
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int check = (dir == load) ? VERIFY_READ : VERIFY_WRITE;
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int size = ((insn >> 19) & 3) == 3 ? 8 : 4;
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if ((regs->pc | regs->npc) & 3)
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return 0;
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/* Must access_ok() in all the necessary places. */
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#define WINREG_ADDR(regnum) \
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((void __user *)(((unsigned long *)regs->u_regs[UREG_FP])+(regnum)))
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|
reg = (insn >> 25) & 0x1f;
|
|
if (reg >= 16) {
|
|
if (!access_ok(check, WINREG_ADDR(reg - 16), size))
|
|
return -EFAULT;
|
|
}
|
|
reg = (insn >> 14) & 0x1f;
|
|
if (reg >= 16) {
|
|
if (!access_ok(check, WINREG_ADDR(reg - 16), size))
|
|
return -EFAULT;
|
|
}
|
|
if (!(insn & 0x2000)) {
|
|
reg = (insn & 0x1f);
|
|
if (reg >= 16) {
|
|
if (!access_ok(check, WINREG_ADDR(reg - 16), size))
|
|
return -EFAULT;
|
|
}
|
|
}
|
|
#undef WINREG_ADDR
|
|
return 0;
|
|
}
|
|
|
|
void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn) __asm__ ("user_mna_trap_fault");
|
|
|
|
void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
|
|
{
|
|
siginfo_t info;
|
|
|
|
info.si_signo = SIGBUS;
|
|
info.si_errno = 0;
|
|
info.si_code = BUS_ADRALN;
|
|
info.si_addr = (void __user *)safe_compute_effective_address(regs, insn);
|
|
info.si_trapno = 0;
|
|
send_sig_info(SIGBUS, &info, current);
|
|
}
|
|
|
|
asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
|
|
{
|
|
enum direction dir;
|
|
|
|
lock_kernel();
|
|
if(!(current->thread.flags & SPARC_FLAG_UNALIGNED) ||
|
|
(((insn >> 30) & 3) != 3))
|
|
goto kill_user;
|
|
dir = decode_direction(insn);
|
|
if(!ok_for_user(regs, insn, dir)) {
|
|
goto kill_user;
|
|
} else {
|
|
int size = decode_access_size(insn);
|
|
unsigned long addr;
|
|
|
|
if(floating_point_load_or_store_p(insn)) {
|
|
printk("User FPU load/store unaligned unsupported.\n");
|
|
goto kill_user;
|
|
}
|
|
|
|
addr = compute_effective_address(regs, insn);
|
|
switch(dir) {
|
|
case load:
|
|
do_integer_load(fetch_reg_addr(((insn>>25)&0x1f), regs),
|
|
size, (unsigned long *) addr,
|
|
decode_signedness(insn),
|
|
user_unaligned_trap_fault);
|
|
break;
|
|
|
|
case store:
|
|
do_integer_store(((insn>>25)&0x1f), size,
|
|
(unsigned long *) addr, regs,
|
|
user_unaligned_trap_fault);
|
|
break;
|
|
|
|
case both:
|
|
#if 0 /* unsupported */
|
|
do_atomic(fetch_reg_addr(((insn>>25)&0x1f), regs),
|
|
(unsigned long *) addr,
|
|
user_unaligned_trap_fault);
|
|
#else
|
|
/*
|
|
* This was supported in 2.4. However, we question
|
|
* the value of SWAP instruction across word boundaries.
|
|
*/
|
|
printk("Unaligned SWAP unsupported.\n");
|
|
goto kill_user;
|
|
#endif
|
|
break;
|
|
|
|
default:
|
|
unaligned_panic("Impossible user unaligned trap.");
|
|
|
|
__asm__ __volatile__ ("\n"
|
|
"user_unaligned_trap_fault:\n\t"
|
|
"mov %0, %%o0\n\t"
|
|
"call user_mna_trap_fault\n\t"
|
|
" mov %1, %%o1\n\t"
|
|
:
|
|
: "r" (regs), "r" (insn)
|
|
: "o0", "o1", "o2", "o3", "o4", "o5", "o7",
|
|
"g1", "g2", "g3", "g4", "g5", "g7", "cc");
|
|
goto out;
|
|
}
|
|
advance(regs);
|
|
goto out;
|
|
}
|
|
|
|
kill_user:
|
|
user_mna_trap_fault(regs, insn);
|
|
out:
|
|
unlock_kernel();
|
|
}
|