490 lines
12 KiB
C
490 lines
12 KiB
C
/*
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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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* Copyright (C) 2001 - 2007 Tensilica Inc.
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*
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* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
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* Chris Zankel <chris@zankel.net>
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* Scott Foehner<sfoehner@yahoo.com>,
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* Kevin Chea
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* Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
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*/
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#include <linux/errno.h>
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#include <linux/hw_breakpoint.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/perf_event.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <linux/security.h>
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#include <linux/signal.h>
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#include <linux/smp.h>
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#include <linux/tracehook.h>
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#include <linux/uaccess.h>
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#include <asm/coprocessor.h>
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#include <asm/elf.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/ptrace.h>
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void user_enable_single_step(struct task_struct *child)
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{
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child->ptrace |= PT_SINGLESTEP;
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}
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void user_disable_single_step(struct task_struct *child)
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{
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child->ptrace &= ~PT_SINGLESTEP;
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}
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/*
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* Called by kernel/ptrace.c when detaching to disable single stepping.
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*/
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void ptrace_disable(struct task_struct *child)
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{
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/* Nothing to do.. */
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}
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static int ptrace_getregs(struct task_struct *child, void __user *uregs)
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{
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struct pt_regs *regs = task_pt_regs(child);
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xtensa_gregset_t __user *gregset = uregs;
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unsigned long wb = regs->windowbase;
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int i;
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if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
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return -EIO;
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__put_user(regs->pc, &gregset->pc);
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__put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
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__put_user(regs->lbeg, &gregset->lbeg);
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__put_user(regs->lend, &gregset->lend);
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__put_user(regs->lcount, &gregset->lcount);
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__put_user(regs->windowstart, &gregset->windowstart);
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__put_user(regs->windowbase, &gregset->windowbase);
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__put_user(regs->threadptr, &gregset->threadptr);
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for (i = 0; i < XCHAL_NUM_AREGS; i++)
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__put_user(regs->areg[i],
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gregset->a + ((wb * 4 + i) % XCHAL_NUM_AREGS));
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return 0;
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}
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static int ptrace_setregs(struct task_struct *child, void __user *uregs)
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{
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struct pt_regs *regs = task_pt_regs(child);
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xtensa_gregset_t *gregset = uregs;
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const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
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unsigned long ps;
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unsigned long wb, ws;
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if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
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return -EIO;
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__get_user(regs->pc, &gregset->pc);
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__get_user(ps, &gregset->ps);
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__get_user(regs->lbeg, &gregset->lbeg);
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__get_user(regs->lend, &gregset->lend);
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__get_user(regs->lcount, &gregset->lcount);
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__get_user(ws, &gregset->windowstart);
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__get_user(wb, &gregset->windowbase);
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__get_user(regs->threadptr, &gregset->threadptr);
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regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
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if (wb >= XCHAL_NUM_AREGS / 4)
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return -EFAULT;
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if (wb != regs->windowbase || ws != regs->windowstart) {
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unsigned long rotws, wmask;
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rotws = (((ws | (ws << WSBITS)) >> wb) &
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((1 << WSBITS) - 1)) & ~1;
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wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) |
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(rotws & 0xF) | 1;
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regs->windowbase = wb;
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regs->windowstart = ws;
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regs->wmask = wmask;
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}
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if (wb != 0 && __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
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gregset->a, wb * 16))
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return -EFAULT;
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if (__copy_from_user(regs->areg, gregset->a + wb * 4,
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(WSBITS - wb) * 16))
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return -EFAULT;
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return 0;
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}
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static int ptrace_getxregs(struct task_struct *child, void __user *uregs)
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{
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struct pt_regs *regs = task_pt_regs(child);
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struct thread_info *ti = task_thread_info(child);
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elf_xtregs_t __user *xtregs = uregs;
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int ret = 0;
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if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
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return -EIO;
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#if XTENSA_HAVE_COPROCESSORS
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/* Flush all coprocessor registers to memory. */
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coprocessor_flush_all(ti);
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ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
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sizeof(xtregs_coprocessor_t));
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#endif
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ret |= __copy_to_user(&xtregs->opt, ®s->xtregs_opt,
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sizeof(xtregs->opt));
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ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
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sizeof(xtregs->user));
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return ret ? -EFAULT : 0;
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}
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static int ptrace_setxregs(struct task_struct *child, void __user *uregs)
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{
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struct thread_info *ti = task_thread_info(child);
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struct pt_regs *regs = task_pt_regs(child);
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elf_xtregs_t *xtregs = uregs;
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int ret = 0;
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if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t)))
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return -EFAULT;
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#if XTENSA_HAVE_COPROCESSORS
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/* Flush all coprocessors before we overwrite them. */
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coprocessor_flush_all(ti);
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coprocessor_release_all(ti);
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ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0,
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sizeof(xtregs_coprocessor_t));
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#endif
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ret |= __copy_from_user(®s->xtregs_opt, &xtregs->opt,
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sizeof(xtregs->opt));
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ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
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sizeof(xtregs->user));
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return ret ? -EFAULT : 0;
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}
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static int ptrace_peekusr(struct task_struct *child, long regno,
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long __user *ret)
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{
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struct pt_regs *regs;
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unsigned long tmp;
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regs = task_pt_regs(child);
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tmp = 0; /* Default return value. */
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switch(regno) {
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case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
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tmp = regs->areg[regno - REG_AR_BASE];
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break;
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case REG_A_BASE ... REG_A_BASE + 15:
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tmp = regs->areg[regno - REG_A_BASE];
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break;
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case REG_PC:
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tmp = regs->pc;
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break;
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case REG_PS:
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/* Note: PS.EXCM is not set while user task is running;
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* its being set in regs is for exception handling
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* convenience.
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*/
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tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
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break;
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case REG_WB:
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break; /* tmp = 0 */
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case REG_WS:
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{
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unsigned long wb = regs->windowbase;
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unsigned long ws = regs->windowstart;
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tmp = ((ws >> wb) | (ws << (WSBITS - wb))) &
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((1 << WSBITS) - 1);
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break;
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}
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case REG_LBEG:
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tmp = regs->lbeg;
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break;
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case REG_LEND:
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tmp = regs->lend;
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break;
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case REG_LCOUNT:
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tmp = regs->lcount;
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break;
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case REG_SAR:
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tmp = regs->sar;
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break;
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case SYSCALL_NR:
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tmp = regs->syscall;
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break;
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default:
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return -EIO;
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}
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return put_user(tmp, ret);
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}
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static int ptrace_pokeusr(struct task_struct *child, long regno, long val)
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{
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struct pt_regs *regs;
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regs = task_pt_regs(child);
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switch (regno) {
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case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
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regs->areg[regno - REG_AR_BASE] = val;
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break;
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case REG_A_BASE ... REG_A_BASE + 15:
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regs->areg[regno - REG_A_BASE] = val;
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break;
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case REG_PC:
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regs->pc = val;
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break;
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case SYSCALL_NR:
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regs->syscall = val;
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break;
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default:
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return -EIO;
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}
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return 0;
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}
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#ifdef CONFIG_HAVE_HW_BREAKPOINT
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static void ptrace_hbptriggered(struct perf_event *bp,
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struct perf_sample_data *data,
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struct pt_regs *regs)
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{
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int i;
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siginfo_t info;
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struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
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if (bp->attr.bp_type & HW_BREAKPOINT_X) {
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for (i = 0; i < XCHAL_NUM_IBREAK; ++i)
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if (current->thread.ptrace_bp[i] == bp)
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break;
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i <<= 1;
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} else {
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for (i = 0; i < XCHAL_NUM_DBREAK; ++i)
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if (current->thread.ptrace_wp[i] == bp)
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break;
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i = (i << 1) | 1;
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}
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info.si_signo = SIGTRAP;
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info.si_errno = i;
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info.si_code = TRAP_HWBKPT;
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info.si_addr = (void __user *)bkpt->address;
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force_sig_info(SIGTRAP, &info, current);
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}
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static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
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{
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struct perf_event_attr attr;
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ptrace_breakpoint_init(&attr);
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/* Initialise fields to sane defaults. */
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attr.bp_addr = 0;
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attr.bp_len = 1;
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attr.bp_type = type;
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attr.disabled = 1;
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return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
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tsk);
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}
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/*
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* Address bit 0 choose instruction (0) or data (1) break register, bits
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* 31..1 are the register number.
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* Both PTRACE_GETHBPREGS and PTRACE_SETHBPREGS transfer two 32-bit words:
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* address (0) and control (1).
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* Instruction breakpoint contorl word is 0 to clear breakpoint, 1 to set.
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* Data breakpoint control word bit 31 is 'trigger on store', bit 30 is
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* 'trigger on load, bits 29..0 are length. Length 0 is used to clear a
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* breakpoint. To set a breakpoint length must be a power of 2 in the range
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* 1..64 and the address must be length-aligned.
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*/
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static long ptrace_gethbpregs(struct task_struct *child, long addr,
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long __user *datap)
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{
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struct perf_event *bp;
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u32 user_data[2] = {0};
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bool dbreak = addr & 1;
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unsigned idx = addr >> 1;
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if ((!dbreak && idx >= XCHAL_NUM_IBREAK) ||
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(dbreak && idx >= XCHAL_NUM_DBREAK))
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return -EINVAL;
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if (dbreak)
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bp = child->thread.ptrace_wp[idx];
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else
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bp = child->thread.ptrace_bp[idx];
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if (bp) {
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user_data[0] = bp->attr.bp_addr;
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user_data[1] = bp->attr.disabled ? 0 : bp->attr.bp_len;
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if (dbreak) {
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if (bp->attr.bp_type & HW_BREAKPOINT_R)
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user_data[1] |= DBREAKC_LOAD_MASK;
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if (bp->attr.bp_type & HW_BREAKPOINT_W)
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user_data[1] |= DBREAKC_STOR_MASK;
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}
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}
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if (copy_to_user(datap, user_data, sizeof(user_data)))
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return -EFAULT;
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return 0;
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}
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static long ptrace_sethbpregs(struct task_struct *child, long addr,
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long __user *datap)
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{
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struct perf_event *bp;
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struct perf_event_attr attr;
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u32 user_data[2];
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bool dbreak = addr & 1;
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unsigned idx = addr >> 1;
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int bp_type = 0;
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if ((!dbreak && idx >= XCHAL_NUM_IBREAK) ||
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(dbreak && idx >= XCHAL_NUM_DBREAK))
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return -EINVAL;
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if (copy_from_user(user_data, datap, sizeof(user_data)))
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return -EFAULT;
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if (dbreak) {
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bp = child->thread.ptrace_wp[idx];
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if (user_data[1] & DBREAKC_LOAD_MASK)
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bp_type |= HW_BREAKPOINT_R;
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if (user_data[1] & DBREAKC_STOR_MASK)
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bp_type |= HW_BREAKPOINT_W;
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} else {
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bp = child->thread.ptrace_bp[idx];
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bp_type = HW_BREAKPOINT_X;
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}
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if (!bp) {
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bp = ptrace_hbp_create(child,
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bp_type ? bp_type : HW_BREAKPOINT_RW);
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if (IS_ERR(bp))
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return PTR_ERR(bp);
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if (dbreak)
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child->thread.ptrace_wp[idx] = bp;
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else
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child->thread.ptrace_bp[idx] = bp;
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}
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attr = bp->attr;
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attr.bp_addr = user_data[0];
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attr.bp_len = user_data[1] & ~(DBREAKC_LOAD_MASK | DBREAKC_STOR_MASK);
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attr.bp_type = bp_type;
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attr.disabled = !attr.bp_len;
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return modify_user_hw_breakpoint(bp, &attr);
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}
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#endif
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long arch_ptrace(struct task_struct *child, long request,
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unsigned long addr, unsigned long data)
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{
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int ret = -EPERM;
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void __user *datap = (void __user *) data;
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switch (request) {
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case PTRACE_PEEKTEXT: /* read word at location addr. */
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case PTRACE_PEEKDATA:
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ret = generic_ptrace_peekdata(child, addr, data);
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break;
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case PTRACE_PEEKUSR: /* read register specified by addr. */
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ret = ptrace_peekusr(child, addr, datap);
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break;
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case PTRACE_POKETEXT: /* write the word at location addr. */
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case PTRACE_POKEDATA:
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ret = generic_ptrace_pokedata(child, addr, data);
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break;
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case PTRACE_POKEUSR: /* write register specified by addr. */
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ret = ptrace_pokeusr(child, addr, data);
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break;
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case PTRACE_GETREGS:
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ret = ptrace_getregs(child, datap);
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break;
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case PTRACE_SETREGS:
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ret = ptrace_setregs(child, datap);
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break;
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case PTRACE_GETXTREGS:
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ret = ptrace_getxregs(child, datap);
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break;
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case PTRACE_SETXTREGS:
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ret = ptrace_setxregs(child, datap);
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break;
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#ifdef CONFIG_HAVE_HW_BREAKPOINT
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case PTRACE_GETHBPREGS:
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ret = ptrace_gethbpregs(child, addr, datap);
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break;
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case PTRACE_SETHBPREGS:
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ret = ptrace_sethbpregs(child, addr, datap);
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break;
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#endif
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default:
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ret = ptrace_request(child, request, addr, data);
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break;
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}
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return ret;
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}
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unsigned long do_syscall_trace_enter(struct pt_regs *regs)
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{
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if (test_thread_flag(TIF_SYSCALL_TRACE) &&
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tracehook_report_syscall_entry(regs))
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return -1;
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return regs->areg[2];
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}
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void do_syscall_trace_leave(struct pt_regs *regs)
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{
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int step;
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step = test_thread_flag(TIF_SINGLESTEP);
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if (step || test_thread_flag(TIF_SYSCALL_TRACE))
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tracehook_report_syscall_exit(regs, step);
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}
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