/* * Kernel support for the ptrace() and syscall tracing interfaces. * * Copyright (C) 1999-2005 Hewlett-Packard Co * David Mosberger-Tang <davidm@hpl.hp.com> * * Derived from the x86 and Alpha versions. */ #include <linux/config.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/ptrace.h> #include <linux/smp_lock.h> #include <linux/user.h> #include <linux/security.h> #include <linux/audit.h> #include <linux/signal.h> #include <asm/pgtable.h> #include <asm/processor.h> #include <asm/ptrace_offsets.h> #include <asm/rse.h> #include <asm/system.h> #include <asm/uaccess.h> #include <asm/unwind.h> #ifdef CONFIG_PERFMON #include <asm/perfmon.h> #endif #include "entry.h" /* * Bits in the PSR that we allow ptrace() to change: * be, up, ac, mfl, mfh (the user mask; five bits total) * db (debug breakpoint fault; one bit) * id (instruction debug fault disable; one bit) * dd (data debug fault disable; one bit) * ri (restart instruction; two bits) * is (instruction set; one bit) */ #define IPSR_MASK (IA64_PSR_UM | IA64_PSR_DB | IA64_PSR_IS \ | IA64_PSR_ID | IA64_PSR_DD | IA64_PSR_RI) #define MASK(nbits) ((1UL << (nbits)) - 1) /* mask with NBITS bits set */ #define PFM_MASK MASK(38) #define PTRACE_DEBUG 0 #if PTRACE_DEBUG # define dprintk(format...) printk(format) # define inline #else # define dprintk(format...) #endif /* Return TRUE if PT was created due to kernel-entry via a system-call. */ static inline int in_syscall (struct pt_regs *pt) { return (long) pt->cr_ifs >= 0; } /* * Collect the NaT bits for r1-r31 from scratch_unat and return a NaT * bitset where bit i is set iff the NaT bit of register i is set. */ unsigned long ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat) { # define GET_BITS(first, last, unat) \ ({ \ unsigned long bit = ia64_unat_pos(&pt->r##first); \ unsigned long nbits = (last - first + 1); \ unsigned long mask = MASK(nbits) << first; \ unsigned long dist; \ if (bit < first) \ dist = 64 + bit - first; \ else \ dist = bit - first; \ ia64_rotr(unat, dist) & mask; \ }) unsigned long val; /* * Registers that are stored consecutively in struct pt_regs * can be handled in parallel. If the register order in * struct_pt_regs changes, this code MUST be updated. */ val = GET_BITS( 1, 1, scratch_unat); val |= GET_BITS( 2, 3, scratch_unat); val |= GET_BITS(12, 13, scratch_unat); val |= GET_BITS(14, 14, scratch_unat); val |= GET_BITS(15, 15, scratch_unat); val |= GET_BITS( 8, 11, scratch_unat); val |= GET_BITS(16, 31, scratch_unat); return val; # undef GET_BITS } /* * Set the NaT bits for the scratch registers according to NAT and * return the resulting unat (assuming the scratch registers are * stored in PT). */ unsigned long ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat) { # define PUT_BITS(first, last, nat) \ ({ \ unsigned long bit = ia64_unat_pos(&pt->r##first); \ unsigned long nbits = (last - first + 1); \ unsigned long mask = MASK(nbits) << first; \ long dist; \ if (bit < first) \ dist = 64 + bit - first; \ else \ dist = bit - first; \ ia64_rotl(nat & mask, dist); \ }) unsigned long scratch_unat; /* * Registers that are stored consecutively in struct pt_regs * can be handled in parallel. If the register order in * struct_pt_regs changes, this code MUST be updated. */ scratch_unat = PUT_BITS( 1, 1, nat); scratch_unat |= PUT_BITS( 2, 3, nat); scratch_unat |= PUT_BITS(12, 13, nat); scratch_unat |= PUT_BITS(14, 14, nat); scratch_unat |= PUT_BITS(15, 15, nat); scratch_unat |= PUT_BITS( 8, 11, nat); scratch_unat |= PUT_BITS(16, 31, nat); return scratch_unat; # undef PUT_BITS } #define IA64_MLX_TEMPLATE 0x2 #define IA64_MOVL_OPCODE 6 void ia64_increment_ip (struct pt_regs *regs) { unsigned long w0, ri = ia64_psr(regs)->ri + 1; if (ri > 2) { ri = 0; regs->cr_iip += 16; } else if (ri == 2) { get_user(w0, (char __user *) regs->cr_iip + 0); if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) { /* * rfi'ing to slot 2 of an MLX bundle causes * an illegal operation fault. We don't want * that to happen... */ ri = 0; regs->cr_iip += 16; } } ia64_psr(regs)->ri = ri; } void ia64_decrement_ip (struct pt_regs *regs) { unsigned long w0, ri = ia64_psr(regs)->ri - 1; if (ia64_psr(regs)->ri == 0) { regs->cr_iip -= 16; ri = 2; get_user(w0, (char __user *) regs->cr_iip + 0); if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) { /* * rfi'ing to slot 2 of an MLX bundle causes * an illegal operation fault. We don't want * that to happen... */ ri = 1; } } ia64_psr(regs)->ri = ri; } /* * This routine is used to read an rnat bits that are stored on the * kernel backing store. Since, in general, the alignment of the user * and kernel are different, this is not completely trivial. In * essence, we need to construct the user RNAT based on up to two * kernel RNAT values and/or the RNAT value saved in the child's * pt_regs. * * user rbs * * +--------+ <-- lowest address * | slot62 | * +--------+ * | rnat | 0x....1f8 * +--------+ * | slot00 | \ * +--------+ | * | slot01 | > child_regs->ar_rnat * +--------+ | * | slot02 | / kernel rbs * +--------+ +--------+ * <- child_regs->ar_bspstore | slot61 | <-- krbs * +- - - - + +--------+ * | slot62 | * +- - - - + +--------+ * | rnat | * +- - - - + +--------+ * vrnat | slot00 | * +- - - - + +--------+ * = = * +--------+ * | slot00 | \ * +--------+ | * | slot01 | > child_stack->ar_rnat * +--------+ | * | slot02 | / * +--------+ * <--- child_stack->ar_bspstore * * The way to think of this code is as follows: bit 0 in the user rnat * corresponds to some bit N (0 <= N <= 62) in one of the kernel rnat * value. The kernel rnat value holding this bit is stored in * variable rnat0. rnat1 is loaded with the kernel rnat value that * form the upper bits of the user rnat value. * * Boundary cases: * * o when reading the rnat "below" the first rnat slot on the kernel * backing store, rnat0/rnat1 are set to 0 and the low order bits are * merged in from pt->ar_rnat. * * o when reading the rnat "above" the last rnat slot on the kernel * backing store, rnat0/rnat1 gets its value from sw->ar_rnat. */ static unsigned long get_rnat (struct task_struct *task, struct switch_stack *sw, unsigned long *krbs, unsigned long *urnat_addr, unsigned long *urbs_end) { unsigned long rnat0 = 0, rnat1 = 0, urnat = 0, *slot0_kaddr; unsigned long umask = 0, mask, m; unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift; long num_regs, nbits; struct pt_regs *pt; pt = task_pt_regs(task); kbsp = (unsigned long *) sw->ar_bspstore; ubspstore = (unsigned long *) pt->ar_bspstore; if (urbs_end < urnat_addr) nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_end); else nbits = 63; mask = MASK(nbits); /* * First, figure out which bit number slot 0 in user-land maps * to in the kernel rnat. Do this by figuring out how many * register slots we're beyond the user's backingstore and * then computing the equivalent address in kernel space. */ num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1); slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs); shift = ia64_rse_slot_num(slot0_kaddr); rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr); rnat0_kaddr = rnat1_kaddr - 64; if (ubspstore + 63 > urnat_addr) { /* some bits need to be merged in from pt->ar_rnat */ umask = MASK(ia64_rse_slot_num(ubspstore)) & mask; urnat = (pt->ar_rnat & umask); mask &= ~umask; if (!mask) return urnat; } m = mask << shift; if (rnat0_kaddr >= kbsp) rnat0 = sw->ar_rnat; else if (rnat0_kaddr > krbs) rnat0 = *rnat0_kaddr; urnat |= (rnat0 & m) >> shift; m = mask >> (63 - shift); if (rnat1_kaddr >= kbsp) rnat1 = sw->ar_rnat; else if (rnat1_kaddr > krbs) rnat1 = *rnat1_kaddr; urnat |= (rnat1 & m) << (63 - shift); return urnat; } /* * The reverse of get_rnat. */ static void put_rnat (struct task_struct *task, struct switch_stack *sw, unsigned long *krbs, unsigned long *urnat_addr, unsigned long urnat, unsigned long *urbs_end) { unsigned long rnat0 = 0, rnat1 = 0, *slot0_kaddr, umask = 0, mask, m; unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift; long num_regs, nbits; struct pt_regs *pt; unsigned long cfm, *urbs_kargs; pt = task_pt_regs(task); kbsp = (unsigned long *) sw->ar_bspstore; ubspstore = (unsigned long *) pt->ar_bspstore; urbs_kargs = urbs_end; if (in_syscall(pt)) { /* * If entered via syscall, don't allow user to set rnat bits * for syscall args. */ cfm = pt->cr_ifs; urbs_kargs = ia64_rse_skip_regs(urbs_end, -(cfm & 0x7f)); } if (urbs_kargs >= urnat_addr) nbits = 63; else { if ((urnat_addr - 63) >= urbs_kargs) return; nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_kargs); } mask = MASK(nbits); /* * First, figure out which bit number slot 0 in user-land maps * to in the kernel rnat. Do this by figuring out how many * register slots we're beyond the user's backingstore and * then computing the equivalent address in kernel space. */ num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1); slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs); shift = ia64_rse_slot_num(slot0_kaddr); rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr); rnat0_kaddr = rnat1_kaddr - 64; if (ubspstore + 63 > urnat_addr) { /* some bits need to be place in pt->ar_rnat: */ umask = MASK(ia64_rse_slot_num(ubspstore)) & mask; pt->ar_rnat = (pt->ar_rnat & ~umask) | (urnat & umask); mask &= ~umask; if (!mask) return; } /* * Note: Section 11.1 of the EAS guarantees that bit 63 of an * rnat slot is ignored. so we don't have to clear it here. */ rnat0 = (urnat << shift); m = mask << shift; if (rnat0_kaddr >= kbsp) sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat0 & m); else if (rnat0_kaddr > krbs) *rnat0_kaddr = ((*rnat0_kaddr & ~m) | (rnat0 & m)); rnat1 = (urnat >> (63 - shift)); m = mask >> (63 - shift); if (rnat1_kaddr >= kbsp) sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat1 & m); else if (rnat1_kaddr > krbs) *rnat1_kaddr = ((*rnat1_kaddr & ~m) | (rnat1 & m)); } static inline int on_kernel_rbs (unsigned long addr, unsigned long bspstore, unsigned long urbs_end) { unsigned long *rnat_addr = ia64_rse_rnat_addr((unsigned long *) urbs_end); return (addr >= bspstore && addr <= (unsigned long) rnat_addr); } /* * Read a word from the user-level backing store of task CHILD. ADDR * is the user-level address to read the word from, VAL a pointer to * the return value, and USER_BSP gives the end of the user-level * backing store (i.e., it's the address that would be in ar.bsp after * the user executed a "cover" instruction). * * This routine takes care of accessing the kernel register backing * store for those registers that got spilled there. It also takes * care of calculating the appropriate RNaT collection words. */ long ia64_peek (struct task_struct *child, struct switch_stack *child_stack, unsigned long user_rbs_end, unsigned long addr, long *val) { unsigned long *bspstore, *krbs, regnum, *laddr, *urbs_end, *rnat_addr; struct pt_regs *child_regs; size_t copied; long ret; urbs_end = (long *) user_rbs_end; laddr = (unsigned long *) addr; child_regs = task_pt_regs(child); bspstore = (unsigned long *) child_regs->ar_bspstore; krbs = (unsigned long *) child + IA64_RBS_OFFSET/8; if (on_kernel_rbs(addr, (unsigned long) bspstore, (unsigned long) urbs_end)) { /* * Attempt to read the RBS in an area that's actually * on the kernel RBS => read the corresponding bits in * the kernel RBS. */ rnat_addr = ia64_rse_rnat_addr(laddr); ret = get_rnat(child, child_stack, krbs, rnat_addr, urbs_end); if (laddr == rnat_addr) { /* return NaT collection word itself */ *val = ret; return 0; } if (((1UL << ia64_rse_slot_num(laddr)) & ret) != 0) { /* * It is implementation dependent whether the * data portion of a NaT value gets saved on a * st8.spill or RSE spill (e.g., see EAS 2.6, * 4.4.4.6 Register Spill and Fill). To get * consistent behavior across all possible * IA-64 implementations, we return zero in * this case. */ *val = 0; return 0; } if (laddr < urbs_end) { /* * The desired word is on the kernel RBS and * is not a NaT. */ regnum = ia64_rse_num_regs(bspstore, laddr); *val = *ia64_rse_skip_regs(krbs, regnum); return 0; } } copied = access_process_vm(child, addr, &ret, sizeof(ret), 0); if (copied != sizeof(ret)) return -EIO; *val = ret; return 0; } long ia64_poke (struct task_struct *child, struct switch_stack *child_stack, unsigned long user_rbs_end, unsigned long addr, long val) { unsigned long *bspstore, *krbs, regnum, *laddr; unsigned long *urbs_end = (long *) user_rbs_end; struct pt_regs *child_regs; laddr = (unsigned long *) addr; child_regs = task_pt_regs(child); bspstore = (unsigned long *) child_regs->ar_bspstore; krbs = (unsigned long *) child + IA64_RBS_OFFSET/8; if (on_kernel_rbs(addr, (unsigned long) bspstore, (unsigned long) urbs_end)) { /* * Attempt to write the RBS in an area that's actually * on the kernel RBS => write the corresponding bits * in the kernel RBS. */ if (ia64_rse_is_rnat_slot(laddr)) put_rnat(child, child_stack, krbs, laddr, val, urbs_end); else { if (laddr < urbs_end) { regnum = ia64_rse_num_regs(bspstore, laddr); *ia64_rse_skip_regs(krbs, regnum) = val; } } } else if (access_process_vm(child, addr, &val, sizeof(val), 1) != sizeof(val)) return -EIO; return 0; } /* * Calculate the address of the end of the user-level register backing * store. This is the address that would have been stored in ar.bsp * if the user had executed a "cover" instruction right before * entering the kernel. If CFMP is not NULL, it is used to return the * "current frame mask" that was active at the time the kernel was * entered. */ unsigned long ia64_get_user_rbs_end (struct task_struct *child, struct pt_regs *pt, unsigned long *cfmp) { unsigned long *krbs, *bspstore, cfm = pt->cr_ifs; long ndirty; krbs = (unsigned long *) child + IA64_RBS_OFFSET/8; bspstore = (unsigned long *) pt->ar_bspstore; ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19)); if (in_syscall(pt)) ndirty += (cfm & 0x7f); else cfm &= ~(1UL << 63); /* clear valid bit */ if (cfmp) *cfmp = cfm; return (unsigned long) ia64_rse_skip_regs(bspstore, ndirty); } /* * Synchronize (i.e, write) the RSE backing store living in kernel * space to the VM of the CHILD task. SW and PT are the pointers to * the switch_stack and pt_regs structures, respectively. * USER_RBS_END is the user-level address at which the backing store * ends. */ long ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw, unsigned long user_rbs_start, unsigned long user_rbs_end) { unsigned long addr, val; long ret; /* now copy word for word from kernel rbs to user rbs: */ for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) { ret = ia64_peek(child, sw, user_rbs_end, addr, &val); if (ret < 0) return ret; if (access_process_vm(child, addr, &val, sizeof(val), 1) != sizeof(val)) return -EIO; } return 0; } static inline int thread_matches (struct task_struct *thread, unsigned long addr) { unsigned long thread_rbs_end; struct pt_regs *thread_regs; if (ptrace_check_attach(thread, 0) < 0) /* * If the thread is not in an attachable state, we'll * ignore it. The net effect is that if ADDR happens * to overlap with the portion of the thread's * register backing store that is currently residing * on the thread's kernel stack, then ptrace() may end * up accessing a stale value. But if the thread * isn't stopped, that's a problem anyhow, so we're * doing as well as we can... */ return 0; thread_regs = task_pt_regs(thread); thread_rbs_end = ia64_get_user_rbs_end(thread, thread_regs, NULL); if (!on_kernel_rbs(addr, thread_regs->ar_bspstore, thread_rbs_end)) return 0; return 1; /* looks like we've got a winner */ } /* * GDB apparently wants to be able to read the register-backing store * of any thread when attached to a given process. If we are peeking * or poking an address that happens to reside in the kernel-backing * store of another thread, we need to attach to that thread, because * otherwise we end up accessing stale data. * * task_list_lock must be read-locked before calling this routine! */ static struct task_struct * find_thread_for_addr (struct task_struct *child, unsigned long addr) { struct task_struct *p; struct mm_struct *mm; struct list_head *this, *next; int mm_users; if (!(mm = get_task_mm(child))) return child; /* -1 because of our get_task_mm(): */ mm_users = atomic_read(&mm->mm_users) - 1; if (mm_users <= 1) goto out; /* not multi-threaded */ /* * Traverse the current process' children list. Every task that * one attaches to becomes a child. And it is only attached children * of the debugger that are of interest (ptrace_check_attach checks * for this). */ list_for_each_safe(this, next, ¤t->children) { p = list_entry(this, struct task_struct, sibling); if (p->mm != mm) continue; if (thread_matches(p, addr)) { child = p; goto out; } } out: mmput(mm); return child; } /* * Write f32-f127 back to task->thread.fph if it has been modified. */ inline void ia64_flush_fph (struct task_struct *task) { struct ia64_psr *psr = ia64_psr(task_pt_regs(task)); /* * Prevent migrating this task while * we're fiddling with the FPU state */ preempt_disable(); if (ia64_is_local_fpu_owner(task) && psr->mfh) { psr->mfh = 0; task->thread.flags |= IA64_THREAD_FPH_VALID; ia64_save_fpu(&task->thread.fph[0]); } preempt_enable(); } /* * Sync the fph state of the task so that it can be manipulated * through thread.fph. If necessary, f32-f127 are written back to * thread.fph or, if the fph state hasn't been used before, thread.fph * is cleared to zeroes. Also, access to f32-f127 is disabled to * ensure that the task picks up the state from thread.fph when it * executes again. */ void ia64_sync_fph (struct task_struct *task) { struct ia64_psr *psr = ia64_psr(task_pt_regs(task)); ia64_flush_fph(task); if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) { task->thread.flags |= IA64_THREAD_FPH_VALID; memset(&task->thread.fph, 0, sizeof(task->thread.fph)); } ia64_drop_fpu(task); psr->dfh = 1; } static int access_fr (struct unw_frame_info *info, int regnum, int hi, unsigned long *data, int write_access) { struct ia64_fpreg fpval; int ret; ret = unw_get_fr(info, regnum, &fpval); if (ret < 0) return ret; if (write_access) { fpval.u.bits[hi] = *data; ret = unw_set_fr(info, regnum, fpval); } else *data = fpval.u.bits[hi]; return ret; } /* * Change the machine-state of CHILD such that it will return via the normal * kernel exit-path, rather than the syscall-exit path. */ static void convert_to_non_syscall (struct task_struct *child, struct pt_regs *pt, unsigned long cfm) { struct unw_frame_info info, prev_info; unsigned long ip, sp, pr; unw_init_from_blocked_task(&info, child); while (1) { prev_info = info; if (unw_unwind(&info) < 0) return; unw_get_sp(&info, &sp); if ((long)((unsigned long)child + IA64_STK_OFFSET - sp) < IA64_PT_REGS_SIZE) { dprintk("ptrace.%s: ran off the top of the kernel " "stack\n", __FUNCTION__); return; } if (unw_get_pr (&prev_info, &pr) < 0) { unw_get_rp(&prev_info, &ip); dprintk("ptrace.%s: failed to read " "predicate register (ip=0x%lx)\n", __FUNCTION__, ip); return; } if (unw_is_intr_frame(&info) && (pr & (1UL << PRED_USER_STACK))) break; } /* * Note: at the time of this call, the target task is blocked * in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL * (aka, "pLvSys") we redirect execution from * .work_pending_syscall_end to .work_processed_kernel. */ unw_get_pr(&prev_info, &pr); pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL)); pr |= (1UL << PRED_NON_SYSCALL); unw_set_pr(&prev_info, pr); pt->cr_ifs = (1UL << 63) | cfm; /* * Clear the memory that is NOT written on syscall-entry to * ensure we do not leak kernel-state to user when execution * resumes. */ pt->r2 = 0; pt->r3 = 0; pt->r14 = 0; memset(&pt->r16, 0, 16*8); /* clear r16-r31 */ memset(&pt->f6, 0, 6*16); /* clear f6-f11 */ pt->b7 = 0; pt->ar_ccv = 0; pt->ar_csd = 0; pt->ar_ssd = 0; } static int access_nat_bits (struct task_struct *child, struct pt_regs *pt, struct unw_frame_info *info, unsigned long *data, int write_access) { unsigned long regnum, nat_bits, scratch_unat, dummy = 0; char nat = 0; if (write_access) { nat_bits = *data; scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits); if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) { dprintk("ptrace: failed to set ar.unat\n"); return -1; } for (regnum = 4; regnum <= 7; ++regnum) { unw_get_gr(info, regnum, &dummy, &nat); unw_set_gr(info, regnum, dummy, (nat_bits >> regnum) & 1); } } else { if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) { dprintk("ptrace: failed to read ar.unat\n"); return -1; } nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat); for (regnum = 4; regnum <= 7; ++regnum) { unw_get_gr(info, regnum, &dummy, &nat); nat_bits |= (nat != 0) << regnum; } *data = nat_bits; } return 0; } static int access_uarea (struct task_struct *child, unsigned long addr, unsigned long *data, int write_access) { unsigned long *ptr, regnum, urbs_end, rnat_addr, cfm; struct switch_stack *sw; struct pt_regs *pt; # define pt_reg_addr(pt, reg) ((void *) \ ((unsigned long) (pt) \ + offsetof(struct pt_regs, reg))) pt = task_pt_regs(child); sw = (struct switch_stack *) (child->thread.ksp + 16); if ((addr & 0x7) != 0) { dprintk("ptrace: unaligned register address 0x%lx\n", addr); return -1; } if (addr < PT_F127 + 16) { /* accessing fph */ if (write_access) ia64_sync_fph(child); else ia64_flush_fph(child); ptr = (unsigned long *) ((unsigned long) &child->thread.fph + addr); } else if ((addr >= PT_F10) && (addr < PT_F11 + 16)) { /* scratch registers untouched by kernel (saved in pt_regs) */ ptr = pt_reg_addr(pt, f10) + (addr - PT_F10); } else if (addr >= PT_F12 && addr < PT_F15 + 16) { /* * Scratch registers untouched by kernel (saved in * switch_stack). */ ptr = (unsigned long *) ((long) sw + (addr - PT_NAT_BITS - 32)); } else if (addr < PT_AR_LC + 8) { /* preserved state: */ struct unw_frame_info info; char nat = 0; int ret; unw_init_from_blocked_task(&info, child); if (unw_unwind_to_user(&info) < 0) return -1; switch (addr) { case PT_NAT_BITS: return access_nat_bits(child, pt, &info, data, write_access); case PT_R4: case PT_R5: case PT_R6: case PT_R7: if (write_access) { /* read NaT bit first: */ unsigned long dummy; ret = unw_get_gr(&info, (addr - PT_R4)/8 + 4, &dummy, &nat); if (ret < 0) return ret; } return unw_access_gr(&info, (addr - PT_R4)/8 + 4, data, &nat, write_access); case PT_B1: case PT_B2: case PT_B3: case PT_B4: case PT_B5: return unw_access_br(&info, (addr - PT_B1)/8 + 1, data, write_access); case PT_AR_EC: return unw_access_ar(&info, UNW_AR_EC, data, write_access); case PT_AR_LC: return unw_access_ar(&info, UNW_AR_LC, data, write_access); default: if (addr >= PT_F2 && addr < PT_F5 + 16) return access_fr(&info, (addr - PT_F2)/16 + 2, (addr & 8) != 0, data, write_access); else if (addr >= PT_F16 && addr < PT_F31 + 16) return access_fr(&info, (addr - PT_F16)/16 + 16, (addr & 8) != 0, data, write_access); else { dprintk("ptrace: rejecting access to register " "address 0x%lx\n", addr); return -1; } } } else if (addr < PT_F9+16) { /* scratch state */ switch (addr) { case PT_AR_BSP: /* * By convention, we use PT_AR_BSP to refer to * the end of the user-level backing store. * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof) * to get the real value of ar.bsp at the time * the kernel was entered. * * Furthermore, when changing the contents of * PT_AR_BSP (or PT_CFM) we MUST copy any * users-level stacked registers that are * stored on the kernel stack back to * user-space because otherwise, we might end * up clobbering kernel stacked registers. * Also, if this happens while the task is * blocked in a system call, which convert the * state such that the non-system-call exit * path is used. This ensures that the proper * state will be picked up when resuming * execution. However, it *also* means that * once we write PT_AR_BSP/PT_CFM, it won't be * possible to modify the syscall arguments of * the pending system call any longer. This * shouldn't be an issue because modifying * PT_AR_BSP/PT_CFM generally implies that * we're either abandoning the pending system * call or that we defer it's re-execution * (e.g., due to GDB doing an inferior * function call). */ urbs_end = ia64_get_user_rbs_end(child, pt, &cfm); if (write_access) { if (*data != urbs_end) { if (ia64_sync_user_rbs(child, sw, pt->ar_bspstore, urbs_end) < 0) return -1; if (in_syscall(pt)) convert_to_non_syscall(child, pt, cfm); /* * Simulate user-level write * of ar.bsp: */ pt->loadrs = 0; pt->ar_bspstore = *data; } } else *data = urbs_end; return 0; case PT_CFM: urbs_end = ia64_get_user_rbs_end(child, pt, &cfm); if (write_access) { if (((cfm ^ *data) & PFM_MASK) != 0) { if (ia64_sync_user_rbs(child, sw, pt->ar_bspstore, urbs_end) < 0) return -1; if (in_syscall(pt)) convert_to_non_syscall(child, pt, cfm); pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK) | (*data & PFM_MASK)); } } else *data = cfm; return 0; case PT_CR_IPSR: if (write_access) pt->cr_ipsr = ((*data & IPSR_MASK) | (pt->cr_ipsr & ~IPSR_MASK)); else *data = (pt->cr_ipsr & IPSR_MASK); return 0; case PT_AR_RSC: if (write_access) pt->ar_rsc = *data | (3 << 2); /* force PL3 */ else *data = pt->ar_rsc; return 0; case PT_AR_RNAT: urbs_end = ia64_get_user_rbs_end(child, pt, NULL); rnat_addr = (long) ia64_rse_rnat_addr((long *) urbs_end); if (write_access) return ia64_poke(child, sw, urbs_end, rnat_addr, *data); else return ia64_peek(child, sw, urbs_end, rnat_addr, data); case PT_R1: ptr = pt_reg_addr(pt, r1); break; case PT_R2: case PT_R3: ptr = pt_reg_addr(pt, r2) + (addr - PT_R2); break; case PT_R8: case PT_R9: case PT_R10: case PT_R11: ptr = pt_reg_addr(pt, r8) + (addr - PT_R8); break; case PT_R12: case PT_R13: ptr = pt_reg_addr(pt, r12) + (addr - PT_R12); break; case PT_R14: ptr = pt_reg_addr(pt, r14); break; case PT_R15: ptr = pt_reg_addr(pt, r15); break; case PT_R16: case PT_R17: case PT_R18: case PT_R19: case PT_R20: case PT_R21: case PT_R22: case PT_R23: case PT_R24: case PT_R25: case PT_R26: case PT_R27: case PT_R28: case PT_R29: case PT_R30: case PT_R31: ptr = pt_reg_addr(pt, r16) + (addr - PT_R16); break; case PT_B0: ptr = pt_reg_addr(pt, b0); break; case PT_B6: ptr = pt_reg_addr(pt, b6); break; case PT_B7: ptr = pt_reg_addr(pt, b7); break; case PT_F6: case PT_F6+8: case PT_F7: case PT_F7+8: case PT_F8: case PT_F8+8: case PT_F9: case PT_F9+8: ptr = pt_reg_addr(pt, f6) + (addr - PT_F6); break; case PT_AR_BSPSTORE: ptr = pt_reg_addr(pt, ar_bspstore); break; case PT_AR_UNAT: ptr = pt_reg_addr(pt, ar_unat); break; case PT_AR_PFS: ptr = pt_reg_addr(pt, ar_pfs); break; case PT_AR_CCV: ptr = pt_reg_addr(pt, ar_ccv); break; case PT_AR_FPSR: ptr = pt_reg_addr(pt, ar_fpsr); break; case PT_CR_IIP: ptr = pt_reg_addr(pt, cr_iip); break; case PT_PR: ptr = pt_reg_addr(pt, pr); break; /* scratch register */ default: /* disallow accessing anything else... */ dprintk("ptrace: rejecting access to register " "address 0x%lx\n", addr); return -1; } } else if (addr <= PT_AR_SSD) { ptr = pt_reg_addr(pt, ar_csd) + (addr - PT_AR_CSD); } else { /* access debug registers */ if (addr >= PT_IBR) { regnum = (addr - PT_IBR) >> 3; ptr = &child->thread.ibr[0]; } else { regnum = (addr - PT_DBR) >> 3; ptr = &child->thread.dbr[0]; } if (regnum >= 8) { dprintk("ptrace: rejecting access to register " "address 0x%lx\n", addr); return -1; } #ifdef CONFIG_PERFMON /* * Check if debug registers are used by perfmon. This * test must be done once we know that we can do the * operation, i.e. the arguments are all valid, but * before we start modifying the state. * * Perfmon needs to keep a count of how many processes * are trying to modify the debug registers for system * wide monitoring sessions. * * We also include read access here, because they may * cause the PMU-installed debug register state * (dbr[], ibr[]) to be reset. The two arrays are also * used by perfmon, but we do not use * IA64_THREAD_DBG_VALID. The registers are restored * by the PMU context switch code. */ if (pfm_use_debug_registers(child)) return -1; #endif if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) { child->thread.flags |= IA64_THREAD_DBG_VALID; memset(child->thread.dbr, 0, sizeof(child->thread.dbr)); memset(child->thread.ibr, 0, sizeof(child->thread.ibr)); } ptr += regnum; if ((regnum & 1) && write_access) { /* don't let the user set kernel-level breakpoints: */ *ptr = *data & ~(7UL << 56); return 0; } } if (write_access) *ptr = *data; else *data = *ptr; return 0; } static long ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr) { unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val; struct unw_frame_info info; struct ia64_fpreg fpval; struct switch_stack *sw; struct pt_regs *pt; long ret, retval = 0; char nat = 0; int i; if (!access_ok(VERIFY_WRITE, ppr, sizeof(struct pt_all_user_regs))) return -EIO; pt = task_pt_regs(child); sw = (struct switch_stack *) (child->thread.ksp + 16); unw_init_from_blocked_task(&info, child); if (unw_unwind_to_user(&info) < 0) { return -EIO; } if (((unsigned long) ppr & 0x7) != 0) { dprintk("ptrace:unaligned register address %p\n", ppr); return -EIO; } if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0 || access_uarea(child, PT_AR_EC, &ec, 0) < 0 || access_uarea(child, PT_AR_LC, &lc, 0) < 0 || access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0 || access_uarea(child, PT_AR_BSP, &bsp, 0) < 0 || access_uarea(child, PT_CFM, &cfm, 0) || access_uarea(child, PT_NAT_BITS, &nat_bits, 0)) return -EIO; /* control regs */ retval |= __put_user(pt->cr_iip, &ppr->cr_iip); retval |= __put_user(psr, &ppr->cr_ipsr); /* app regs */ retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]); retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]); retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]); retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]); retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]); retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]); retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]); retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]); retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]); retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]); retval |= __put_user(cfm, &ppr->cfm); /* gr1-gr3 */ retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long)); retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2); /* gr4-gr7 */ for (i = 4; i < 8; i++) { if (unw_access_gr(&info, i, &val, &nat, 0) < 0) return -EIO; retval |= __put_user(val, &ppr->gr[i]); } /* gr8-gr11 */ retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4); /* gr12-gr15 */ retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2); retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long)); retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long)); /* gr16-gr31 */ retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16); /* b0 */ retval |= __put_user(pt->b0, &ppr->br[0]); /* b1-b5 */ for (i = 1; i < 6; i++) { if (unw_access_br(&info, i, &val, 0) < 0) return -EIO; __put_user(val, &ppr->br[i]); } /* b6-b7 */ retval |= __put_user(pt->b6, &ppr->br[6]); retval |= __put_user(pt->b7, &ppr->br[7]); /* fr2-fr5 */ for (i = 2; i < 6; i++) { if (unw_get_fr(&info, i, &fpval) < 0) return -EIO; retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval)); } /* fr6-fr11 */ retval |= __copy_to_user(&ppr->fr[6], &pt->f6, sizeof(struct ia64_fpreg) * 6); /* fp scratch regs(12-15) */ retval |= __copy_to_user(&ppr->fr[12], &sw->f12, sizeof(struct ia64_fpreg) * 4); /* fr16-fr31 */ for (i = 16; i < 32; i++) { if (unw_get_fr(&info, i, &fpval) < 0) return -EIO; retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval)); } /* fph */ ia64_flush_fph(child); retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph, sizeof(ppr->fr[32]) * 96); /* preds */ retval |= __put_user(pt->pr, &ppr->pr); /* nat bits */ retval |= __put_user(nat_bits, &ppr->nat); ret = retval ? -EIO : 0; return ret; } static long ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr) { unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0; struct unw_frame_info info; struct switch_stack *sw; struct ia64_fpreg fpval; struct pt_regs *pt; long ret, retval = 0; int i; memset(&fpval, 0, sizeof(fpval)); if (!access_ok(VERIFY_READ, ppr, sizeof(struct pt_all_user_regs))) return -EIO; pt = task_pt_regs(child); sw = (struct switch_stack *) (child->thread.ksp + 16); unw_init_from_blocked_task(&info, child); if (unw_unwind_to_user(&info) < 0) { return -EIO; } if (((unsigned long) ppr & 0x7) != 0) { dprintk("ptrace:unaligned register address %p\n", ppr); return -EIO; } /* control regs */ retval |= __get_user(pt->cr_iip, &ppr->cr_iip); retval |= __get_user(psr, &ppr->cr_ipsr); /* app regs */ retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]); retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]); retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]); retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]); retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]); retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]); retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]); retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]); retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]); retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]); retval |= __get_user(cfm, &ppr->cfm); /* gr1-gr3 */ retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long)); retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2); /* gr4-gr7 */ for (i = 4; i < 8; i++) { retval |= __get_user(val, &ppr->gr[i]); /* NaT bit will be set via PT_NAT_BITS: */ if (unw_set_gr(&info, i, val, 0) < 0) return -EIO; } /* gr8-gr11 */ retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4); /* gr12-gr15 */ retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2); retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long)); retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long)); /* gr16-gr31 */ retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16); /* b0 */ retval |= __get_user(pt->b0, &ppr->br[0]); /* b1-b5 */ for (i = 1; i < 6; i++) { retval |= __get_user(val, &ppr->br[i]); unw_set_br(&info, i, val); } /* b6-b7 */ retval |= __get_user(pt->b6, &ppr->br[6]); retval |= __get_user(pt->b7, &ppr->br[7]); /* fr2-fr5 */ for (i = 2; i < 6; i++) { retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval)); if (unw_set_fr(&info, i, fpval) < 0) return -EIO; } /* fr6-fr11 */ retval |= __copy_from_user(&pt->f6, &ppr->fr[6], sizeof(ppr->fr[6]) * 6); /* fp scratch regs(12-15) */ retval |= __copy_from_user(&sw->f12, &ppr->fr[12], sizeof(ppr->fr[12]) * 4); /* fr16-fr31 */ for (i = 16; i < 32; i++) { retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval)); if (unw_set_fr(&info, i, fpval) < 0) return -EIO; } /* fph */ ia64_sync_fph(child); retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32], sizeof(ppr->fr[32]) * 96); /* preds */ retval |= __get_user(pt->pr, &ppr->pr); /* nat bits */ retval |= __get_user(nat_bits, &ppr->nat); retval |= access_uarea(child, PT_CR_IPSR, &psr, 1); retval |= access_uarea(child, PT_AR_RSC, &rsc, 1); retval |= access_uarea(child, PT_AR_EC, &ec, 1); retval |= access_uarea(child, PT_AR_LC, &lc, 1); retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1); retval |= access_uarea(child, PT_AR_BSP, &bsp, 1); retval |= access_uarea(child, PT_CFM, &cfm, 1); retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1); ret = retval ? -EIO : 0; return ret; } /* * Called by kernel/ptrace.c when detaching.. * * Make sure the single step bit is not set. */ void ptrace_disable (struct task_struct *child) { struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child)); /* make sure the single step/taken-branch trap bits are not set: */ child_psr->ss = 0; child_psr->tb = 0; } asmlinkage long sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) { struct pt_regs *pt; unsigned long urbs_end, peek_or_poke; struct task_struct *child; struct switch_stack *sw; long ret; lock_kernel(); ret = -EPERM; if (request == PTRACE_TRACEME) { ret = ptrace_traceme(); goto out; } peek_or_poke = (request == PTRACE_PEEKTEXT || request == PTRACE_PEEKDATA || request == PTRACE_POKETEXT || request == PTRACE_POKEDATA); ret = -ESRCH; read_lock(&tasklist_lock); { child = find_task_by_pid(pid); if (child) { if (peek_or_poke) child = find_thread_for_addr(child, addr); get_task_struct(child); } } read_unlock(&tasklist_lock); if (!child) goto out; ret = -EPERM; if (pid == 1) /* no messing around with init! */ goto out_tsk; if (request == PTRACE_ATTACH) { ret = ptrace_attach(child); goto out_tsk; } ret = ptrace_check_attach(child, request == PTRACE_KILL); if (ret < 0) goto out_tsk; pt = task_pt_regs(child); sw = (struct switch_stack *) (child->thread.ksp + 16); switch (request) { case PTRACE_PEEKTEXT: case PTRACE_PEEKDATA: /* read word at location addr */ urbs_end = ia64_get_user_rbs_end(child, pt, NULL); ret = ia64_peek(child, sw, urbs_end, addr, &data); if (ret == 0) { ret = data; /* ensure "ret" is not mistaken as an error code: */ force_successful_syscall_return(); } goto out_tsk; case PTRACE_POKETEXT: case PTRACE_POKEDATA: /* write the word at location addr */ urbs_end = ia64_get_user_rbs_end(child, pt, NULL); ret = ia64_poke(child, sw, urbs_end, addr, data); goto out_tsk; case PTRACE_PEEKUSR: /* read the word at addr in the USER area */ if (access_uarea(child, addr, &data, 0) < 0) { ret = -EIO; goto out_tsk; } ret = data; /* ensure "ret" is not mistaken as an error code */ force_successful_syscall_return(); goto out_tsk; case PTRACE_POKEUSR: /* write the word at addr in the USER area */ if (access_uarea(child, addr, &data, 1) < 0) { ret = -EIO; goto out_tsk; } ret = 0; goto out_tsk; case PTRACE_OLD_GETSIGINFO: /* for backwards-compatibility */ ret = ptrace_request(child, PTRACE_GETSIGINFO, addr, data); goto out_tsk; case PTRACE_OLD_SETSIGINFO: /* for backwards-compatibility */ ret = ptrace_request(child, PTRACE_SETSIGINFO, addr, data); goto out_tsk; case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ case PTRACE_CONT: /* restart after signal. */ ret = -EIO; if (!valid_signal(data)) goto out_tsk; if (request == PTRACE_SYSCALL) set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); else clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); child->exit_code = data; /* * Make sure the single step/taken-branch trap bits * are not set: */ ia64_psr(pt)->ss = 0; ia64_psr(pt)->tb = 0; wake_up_process(child); ret = 0; goto out_tsk; case PTRACE_KILL: /* * Make the child exit. Best I can do is send it a * sigkill. Perhaps it should be put in the status * that it wants to exit. */ if (child->exit_state == EXIT_ZOMBIE) /* already dead */ goto out_tsk; child->exit_code = SIGKILL; ptrace_disable(child); wake_up_process(child); ret = 0; goto out_tsk; case PTRACE_SINGLESTEP: /* let child execute for one instruction */ case PTRACE_SINGLEBLOCK: ret = -EIO; if (!valid_signal(data)) goto out_tsk; clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); if (request == PTRACE_SINGLESTEP) { ia64_psr(pt)->ss = 1; } else { ia64_psr(pt)->tb = 1; } child->exit_code = data; /* give it a chance to run. */ wake_up_process(child); ret = 0; goto out_tsk; case PTRACE_DETACH: /* detach a process that was attached. */ ret = ptrace_detach(child, data); goto out_tsk; case PTRACE_GETREGS: ret = ptrace_getregs(child, (struct pt_all_user_regs __user *) data); goto out_tsk; case PTRACE_SETREGS: ret = ptrace_setregs(child, (struct pt_all_user_regs __user *) data); goto out_tsk; default: ret = ptrace_request(child, request, addr, data); goto out_tsk; } out_tsk: put_task_struct(child); out: unlock_kernel(); return ret; } void syscall_trace (void) { if (!test_thread_flag(TIF_SYSCALL_TRACE)) return; if (!(current->ptrace & PT_PTRACED)) return; /* * The 0x80 provides a way for the tracing parent to * distinguish between a syscall stop and SIGTRAP delivery. */ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); /* * This isn't the same as continuing with a signal, but it * will do for normal use. strace only continues with a * signal if the stopping signal is not SIGTRAP. -brl */ if (current->exit_code) { send_sig(current->exit_code, current, 1); current->exit_code = 0; } } /* "asmlinkage" so the input arguments are preserved... */ asmlinkage void syscall_trace_enter (long arg0, long arg1, long arg2, long arg3, long arg4, long arg5, long arg6, long arg7, struct pt_regs regs) { if (test_thread_flag(TIF_SYSCALL_TRACE) && (current->ptrace & PT_PTRACED)) syscall_trace(); if (unlikely(current->audit_context)) { long syscall; int arch; if (IS_IA32_PROCESS(®s)) { syscall = regs.r1; arch = AUDIT_ARCH_I386; } else { syscall = regs.r15; arch = AUDIT_ARCH_IA64; } audit_syscall_entry(arch, syscall, arg0, arg1, arg2, arg3); } } /* "asmlinkage" so the input arguments are preserved... */ asmlinkage void syscall_trace_leave (long arg0, long arg1, long arg2, long arg3, long arg4, long arg5, long arg6, long arg7, struct pt_regs regs) { if (unlikely(current->audit_context)) { int success = AUDITSC_RESULT(regs.r10); long result = regs.r8; if (success != AUDITSC_SUCCESS) result = -result; audit_syscall_exit(success, result); } if (test_thread_flag(TIF_SYSCALL_TRACE) && (current->ptrace & PT_PTRACED)) syscall_trace(); }