diff options
| -rw-r--r-- | arch/arc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arc/kernel/Makefile | 3 | ||||
| -rw-r--r-- | arch/arc/kernel/entry.S | 68 | ||||
| -rw-r--r-- | arch/arc/kernel/ptrace.c | 136 |
4 files changed, 206 insertions, 2 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 03347cbde9bd..409b9378032e 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -22,6 +22,7 @@ config ARC select GENERIC_PENDING_IRQ if SMP select GENERIC_SIGALTSTACK select GENERIC_SMP_IDLE_THREAD + select HAVE_ARCH_TRACEHOOK select HAVE_GENERIC_HARDIRQS select HAVE_MEMBLOCK select IRQ_DOMAIN diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile index c9ec0662a4ec..f4885891dabb 100644 --- a/arch/arc/kernel/Makefile +++ b/arch/arc/kernel/Makefile @@ -5,6 +5,9 @@ # it under the terms of the GNU General Public License version 2 as # published by the Free Software Foundation. +# Pass UTS_MACHINE for user_regset definition +CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"' + obj-y := arcksyms.o setup.o irq.o time.o reset.o ptrace.o entry.o process.o obj-y += signal.o traps.o sys.o troubleshoot.o stacktrace.o clk.o obj-y += devtree.o diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 69d0d376e28b..76697aecd165 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -7,6 +7,13 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * + * vineetg: Feb 2011 (ptrace low level code fixes) + * -traced syscall return code (r0) was not saved into pt_regs for restoring + * into user reg-file when traded task rets to user space. + * -syscalls needing arch-wrappers (mainly for passing sp as pt_regs) + * were not invoking post-syscall trace hook (jumping directly into + * ret_from_system_call) + * * vineetg: Nov 2010: * -Vector table jumps (@8 bytes) converted into branches (@4 bytes) * -To maintain the slot size of 8 bytes/vector, added nop, which is @@ -347,6 +354,50 @@ ARC_ENTRY EV_Extension b ret_from_exception ARC_EXIT EV_Extension +;######################### System Call Tracing ######################### + +tracesys: + ; save EFA in case tracer wants the PC of traced task + ; using ERET won't work since next-PC has already committed + lr r12, [efa] + GET_CURR_TASK_FIELD_PTR TASK_THREAD, r11 + st r12, [r11, THREAD_FAULT_ADDR] + + ; PRE Sys Call Ptrace hook + mov r0, sp ; pt_regs needed + bl @syscall_trace_entry + + ; Tracing code now returns the syscall num (orig or modif) + mov r8, r0 + + ; Do the Sys Call as we normally would. + ; Validate the Sys Call number + cmp r8, NR_syscalls + mov.hi r0, -ENOSYS + bhi tracesys_exit + + ; Restore the sys-call args. Mere invocation of the hook abv could have + ; clobbered them (since they are in scratch regs). The tracer could also + ; have deliberately changed the syscall args: r0-r7 + ld r0, [sp, PT_r0] + ld r1, [sp, PT_r1] + ld r2, [sp, PT_r2] + ld r3, [sp, PT_r3] + ld r4, [sp, PT_r4] + ld r5, [sp, PT_r5] + ld r6, [sp, PT_r6] + ld r7, [sp, PT_r7] + ld.as r9, [sys_call_table, r8] + jl [r9] ; Entry into Sys Call Handler + +tracesys_exit: + st r0, [sp, PT_r0] ; sys call return value in pt_regs + + ;POST Sys Call Ptrace Hook + bl @syscall_trace_exit + b ret_from_exception ; NOT ret_from_system_call at is saves r0 which + ; we'd done before calling post hook above + ;################### Break Point TRAP ########################## ; ======= (5b) Trap is due to Break-Point ========= @@ -412,6 +463,11 @@ ARC_ENTRY EV_Trap ; Before doing anything, return from CPU Exception Mode FAKE_RET_FROM_EXCPN r11 + ; If syscall tracing ongoing, invoke pre-pos-hooks + GET_CURR_THR_INFO_FLAGS r10 + btst r10, TIF_SYSCALL_TRACE + bnz tracesys ; this never comes back + ;============ This is normal System Call case ========== ; Sys-call num shd not exceed the total system calls avail cmp r8, NR_syscalls @@ -608,6 +664,10 @@ ARC_ENTRY sys_fork_wrapper bl @sys_fork DISCARD_CALLEE_SAVED_USER + GET_CURR_THR_INFO_FLAGS r10 + btst r10, TIF_SYSCALL_TRACE + bnz tracesys_exit + b ret_from_system_call ARC_EXIT sys_fork_wrapper @@ -616,6 +676,10 @@ ARC_ENTRY sys_vfork_wrapper bl @sys_vfork DISCARD_CALLEE_SAVED_USER + GET_CURR_THR_INFO_FLAGS r10 + btst r10, TIF_SYSCALL_TRACE + bnz tracesys_exit + b ret_from_system_call ARC_EXIT sys_vfork_wrapper @@ -624,5 +688,9 @@ ARC_ENTRY sys_clone_wrapper bl @sys_clone DISCARD_CALLEE_SAVED_USER + GET_CURR_THR_INFO_FLAGS r10 + btst r10, TIF_SYSCALL_TRACE + bnz tracesys_exit + b ret_from_system_call ARC_EXIT sys_clone_wrapper diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c index 1cf944a77f33..c6a81c58d0f3 100644 --- a/arch/arc/kernel/ptrace.c +++ b/arch/arc/kernel/ptrace.c @@ -7,6 +7,122 @@ */ #include <linux/ptrace.h> +#include <linux/tracehook.h> +#include <linux/regset.h> +#include <linux/unistd.h> +#include <linux/elf.h> + +static struct callee_regs *task_callee_regs(struct task_struct *tsk) +{ + struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg; + return tmp; +} + +static int genregs_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + const struct pt_regs *ptregs = task_pt_regs(target); + const struct callee_regs *cregs = task_callee_regs(target); + int ret = 0; + unsigned int stop_pc_val; + +#define REG_O_CHUNK(START, END, PTR) \ + if (!ret) \ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \ + offsetof(struct user_regs_struct, START), \ + offsetof(struct user_regs_struct, END)); + +#define REG_O_ONE(LOC, PTR) \ + if (!ret) \ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \ + offsetof(struct user_regs_struct, LOC), \ + offsetof(struct user_regs_struct, LOC) + 4); + + REG_O_CHUNK(scratch, callee, ptregs); + REG_O_CHUNK(callee, efa, cregs); + REG_O_CHUNK(efa, stop_pc, &target->thread.fault_address); + + if (!ret) { + if (in_brkpt_trap(ptregs)) { + stop_pc_val = target->thread.fault_address; + pr_debug("\t\tstop_pc (brk-pt)\n"); + } else { + stop_pc_val = ptregs->ret; + pr_debug("\t\tstop_pc (others)\n"); + } + + REG_O_ONE(stop_pc, &stop_pc_val); + } + + return ret; +} + +static int genregs_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + const struct pt_regs *ptregs = task_pt_regs(target); + const struct callee_regs *cregs = task_callee_regs(target); + int ret = 0; + +#define REG_IN_CHUNK(FIRST, NEXT, PTR) \ + if (!ret) \ + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \ + (void *)(PTR), \ + offsetof(struct user_regs_struct, FIRST), \ + offsetof(struct user_regs_struct, NEXT)); + +#define REG_IN_ONE(LOC, PTR) \ + if (!ret) \ + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \ + (void *)(PTR), \ + offsetof(struct user_regs_struct, LOC), \ + offsetof(struct user_regs_struct, LOC) + 4); + +#define REG_IGNORE_ONE(LOC) \ + if (!ret) \ + ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \ + offsetof(struct user_regs_struct, LOC), \ + offsetof(struct user_regs_struct, LOC) + 4); + + /* TBD: disallow updates to STATUS32, orig_r8 etc*/ + REG_IN_CHUNK(scratch, callee, ptregs); /* pt_regs[bta..orig_r8] */ + REG_IN_CHUNK(callee, efa, cregs); /* callee_regs[r25..r13] */ + REG_IGNORE_ONE(efa); /* efa update invalid */ + REG_IN_ONE(stop_pc, &ptregs->ret); /* stop_pc: PC update */ + + return ret; +} + +enum arc_getset { + REGSET_GENERAL, +}; + +static const struct user_regset arc_regsets[] = { + [REGSET_GENERAL] = { + .core_note_type = NT_PRSTATUS, + .n = ELF_NGREG, + .size = sizeof(unsigned long), + .align = sizeof(unsigned long), + .get = genregs_get, + .set = genregs_set, + } +}; + +static const struct user_regset_view user_arc_view = { + .name = UTS_MACHINE, + .e_machine = EM_ARCOMPACT, + .regsets = arc_regsets, + .n = ARRAY_SIZE(arc_regsets) +}; + +const struct user_regset_view *task_user_regset_view(struct task_struct *task) +{ + return &user_arc_view; +} void ptrace_disable(struct task_struct *child) { @@ -16,11 +132,27 @@ long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { int ret = -EIO; + + pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data); + + switch (request) { + default: + ret = ptrace_request(child, request, addr, data); + break; + } + return ret; } +asmlinkage int syscall_trace_entry(struct pt_regs *regs) +{ + if (tracehook_report_syscall_entry(regs)) + return ULONG_MAX; -const struct user_regset_view *task_user_regset_view(struct task_struct *task) + return regs->r8; +} + +asmlinkage void syscall_trace_exit(struct pt_regs *regs) { - return (const struct user_regset_view *)NULL; + tracehook_report_syscall_exit(regs, 0); } |
