b92c4f922b
This patch uses MAX_REG_NR consistently to refer to the register file size. FRAME_SIZE isn't sufficient because on x86_64, it is smaller than the ptrace register file size. MAX_REG_NR was introduced as a consistent way to get the number of registers, but wasn't used everywhere it should be. When this causes a problem, it makes PTRACE_SETREGS fail on x86_64 because of a corrupted segment register value in the known-good register file. The patch also adds a register dump at that point in case there are any future problems here. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
145 lines
3.2 KiB
C
145 lines
3.2 KiB
C
/*
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* Copyright (C) 2004 PathScale, Inc
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* Licensed under the GPL
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*/
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#include <errno.h>
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#include <string.h>
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#include "sysdep/ptrace_user.h"
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#include "sysdep/ptrace.h"
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#include "uml-config.h"
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#include "skas_ptregs.h"
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#include "registers.h"
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#include "longjmp.h"
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#include "user.h"
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/* These are set once at boot time and not changed thereafter */
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static unsigned long exec_regs[MAX_REG_NR];
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static unsigned long exec_fp_regs[HOST_FP_SIZE];
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static unsigned long exec_fpx_regs[HOST_XFP_SIZE];
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static int have_fpx_regs = 1;
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void init_thread_registers(union uml_pt_regs *to)
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{
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memcpy(to->skas.regs, exec_regs, sizeof(to->skas.regs));
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memcpy(to->skas.fp, exec_fp_regs, sizeof(to->skas.fp));
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if(have_fpx_regs)
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memcpy(to->skas.xfp, exec_fpx_regs, sizeof(to->skas.xfp));
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}
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/* XXX These need to use [GS]ETFPXREGS and copy_sc_{to,from}_user_skas needs
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* to pass in a sufficiently large buffer
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*/
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int save_fp_registers(int pid, unsigned long *fp_regs)
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{
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if(ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
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return -errno;
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return 0;
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}
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int restore_fp_registers(int pid, unsigned long *fp_regs)
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{
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if(ptrace(PTRACE_SETFPREGS, pid, 0, fp_regs) < 0)
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return -errno;
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return 0;
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}
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static int move_registers(int pid, int int_op, union uml_pt_regs *regs,
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int fp_op, unsigned long *fp_regs)
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{
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if(ptrace(int_op, pid, 0, regs->skas.regs) < 0)
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return -errno;
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if(ptrace(fp_op, pid, 0, fp_regs) < 0)
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return -errno;
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return 0;
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}
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void save_registers(int pid, union uml_pt_regs *regs)
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{
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unsigned long *fp_regs;
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int err, fp_op;
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if(have_fpx_regs){
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fp_op = PTRACE_GETFPXREGS;
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fp_regs = regs->skas.xfp;
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}
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else {
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fp_op = PTRACE_GETFPREGS;
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fp_regs = regs->skas.fp;
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}
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err = move_registers(pid, PTRACE_GETREGS, regs, fp_op, fp_regs);
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if(err)
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panic("save_registers - saving registers failed, errno = %d\n",
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-err);
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}
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void restore_registers(int pid, union uml_pt_regs *regs)
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{
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unsigned long *fp_regs;
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int err, fp_op;
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if(have_fpx_regs){
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fp_op = PTRACE_SETFPXREGS;
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fp_regs = regs->skas.xfp;
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}
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else {
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fp_op = PTRACE_SETFPREGS;
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fp_regs = regs->skas.fp;
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}
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err = move_registers(pid, PTRACE_SETREGS, regs, fp_op, fp_regs);
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if(err)
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panic("restore_registers - saving registers failed, "
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"errno = %d\n", -err);
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}
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void init_registers(int pid)
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{
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int err;
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memset(exec_regs, 0, sizeof(exec_regs));
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err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
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if(err)
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panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
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errno);
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errno = 0;
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err = ptrace(PTRACE_GETFPXREGS, pid, 0, exec_fpx_regs);
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if(!err)
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return;
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if(errno != EIO)
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panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
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errno);
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have_fpx_regs = 0;
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err = ptrace(PTRACE_GETFPREGS, pid, 0, exec_fp_regs);
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if(err)
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panic("check_ptrace : PTRACE_GETFPREGS failed, errno = %d",
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errno);
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}
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void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
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{
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memcpy(regs, exec_regs, sizeof(exec_regs));
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if(fp_regs != NULL)
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memcpy(fp_regs, exec_fp_regs,
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HOST_FP_SIZE * sizeof(unsigned long));
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}
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unsigned long get_thread_reg(int reg, jmp_buf *buf)
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{
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switch(reg){
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case EIP: return buf[0]->__eip;
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case UESP: return buf[0]->__esp;
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case EBP: return buf[0]->__ebp;
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default:
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printk("get_thread_regs - unknown register %d\n", reg);
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return 0;
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}
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}
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