diff options
| -rw-r--r-- | arch/x86/ia32/ia32entry.S | 17 | ||||
| -rw-r--r-- | arch/x86/kernel/entry_32.S | 19 | ||||
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 14 | ||||
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 141 | ||||
| -rw-r--r-- | include/asm-x86/calling.h | 6 | ||||
| -rw-r--r-- | include/asm-x86/ptrace-abi.h | 6 | ||||
| -rw-r--r-- | include/asm-x86/thread_info.h | 17 |
7 files changed, 88 insertions, 132 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 20371d0..8796d19 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -37,6 +37,11 @@ movq %rax,R8(%rsp) .endm + /* + * Reload arg registers from stack in case ptrace changed them. + * We don't reload %eax because syscall_trace_enter() returned + * the value it wants us to use in the table lookup. + */ .macro LOAD_ARGS32 offset movl \offset(%rsp),%r11d movl \offset+8(%rsp),%r10d @@ -46,7 +51,6 @@ movl \offset+48(%rsp),%edx movl \offset+56(%rsp),%esi movl \offset+64(%rsp),%edi - movl \offset+72(%rsp),%eax .endm .macro CFI_STARTPROC32 simple @@ -137,13 +141,12 @@ ENTRY(ia32_sysenter_target) .previous GET_THREAD_INFO(%r10) orl $TS_COMPAT,TI_status(%r10) - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \ - TI_flags(%r10) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) CFI_REMEMBER_STATE jnz sysenter_tracesys -sysenter_do_call: cmpl $(IA32_NR_syscalls-1),%eax ja ia32_badsys +sysenter_do_call: IA32_ARG_FIXUP 1 call *ia32_sys_call_table(,%rax,8) movq %rax,RAX-ARGOFFSET(%rsp) @@ -242,8 +245,7 @@ ENTRY(ia32_cstar_target) .previous GET_THREAD_INFO(%r10) orl $TS_COMPAT,TI_status(%r10) - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \ - TI_flags(%r10) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) CFI_REMEMBER_STATE jnz cstar_tracesys cstar_do_call: @@ -336,8 +338,7 @@ ENTRY(ia32_syscall) SAVE_ARGS 0,0,1 GET_THREAD_INFO(%r10) orl $TS_COMPAT,TI_status(%r10) - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \ - TI_flags(%r10) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) jnz ia32_tracesys ia32_do_syscall: cmpl $(IA32_NR_syscalls-1),%eax diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 0ad987d..cadf73f 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -332,7 +332,7 @@ sysenter_past_esp: GET_THREAD_INFO(%ebp) /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */ - testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp) + testw $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp) jnz syscall_trace_entry cmpl $(nr_syscalls), %eax jae syscall_badsys @@ -370,7 +370,7 @@ ENTRY(system_call) GET_THREAD_INFO(%ebp) # system call tracing in operation / emulation /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */ - testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp) + testw $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp) jnz syscall_trace_entry cmpl $(nr_syscalls), %eax jae syscall_badsys @@ -510,12 +510,8 @@ END(work_pending) syscall_trace_entry: movl $-ENOSYS,PT_EAX(%esp) movl %esp, %eax - xorl %edx,%edx - call do_syscall_trace - cmpl $0, %eax - jne resume_userspace # ret != 0 -> running under PTRACE_SYSEMU, - # so must skip actual syscall - movl PT_ORIG_EAX(%esp), %eax + call syscall_trace_enter + /* What it returned is what we'll actually use. */ cmpl $(nr_syscalls), %eax jnae syscall_call jmp syscall_exit @@ -524,14 +520,13 @@ END(syscall_trace_entry) # perform syscall exit tracing ALIGN syscall_exit_work: - testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl + testb $_TIF_WORK_SYSCALL_EXIT, %cl jz work_pending TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_ANY) # could let do_syscall_trace() call + ENABLE_INTERRUPTS(CLBR_ANY) # could let syscall_trace_leave() call # schedule() instead movl %esp, %eax - movl $1, %edx - call do_syscall_trace + call syscall_trace_leave jmp resume_userspace END(syscall_exit_work) CFI_ENDPROC diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index ae63e58..63001c6 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -349,8 +349,7 @@ ENTRY(system_call_after_swapgs) movq %rcx,RIP-ARGOFFSET(%rsp) CFI_REL_OFFSET rip,RIP-ARGOFFSET GET_THREAD_INFO(%rcx) - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \ - TI_flags(%rcx) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx) jnz tracesys cmpq $__NR_syscall_max,%rax ja badsys @@ -430,7 +429,12 @@ tracesys: FIXUP_TOP_OF_STACK %rdi movq %rsp,%rdi call syscall_trace_enter - LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */ + /* + * Reload arg registers from stack in case ptrace changed them. + * We don't reload %rax because syscall_trace_enter() returned + * the value it wants us to use in the table lookup. + */ + LOAD_ARGS ARGOFFSET, 1 RESTORE_REST cmpq $__NR_syscall_max,%rax ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ @@ -483,7 +487,7 @@ int_very_careful: ENABLE_INTERRUPTS(CLBR_NONE) SAVE_REST /* Check for syscall exit trace */ - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edx + testl $_TIF_WORK_SYSCALL_EXIT,%edx jz int_signal pushq %rdi CFI_ADJUST_CFA_OFFSET 8 @@ -491,7 +495,7 @@ int_very_careful: call syscall_trace_leave popq %rdi CFI_ADJUST_CFA_OFFSET -8 - andl $~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi + andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi jmp int_restore_rest int_signal: diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 77040b6..34e77b1 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -1357,8 +1357,6 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) #endif } -#ifdef CONFIG_X86_32 - void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) { struct siginfo info; @@ -1377,89 +1375,10 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) force_sig_info(SIGTRAP, &info, tsk); } -/* notification of system call entry/exit - * - triggered by current->work.syscall_trace - */ -int do_syscall_trace(struct pt_regs *regs, int entryexit) -{ - int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU); - /* - * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall - * interception - */ - int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP); - int ret = 0; - - /* do the secure computing check first */ - if (!entryexit) - secure_computing(regs->orig_ax); - - if (unlikely(current->audit_context)) { - if (entryexit) - audit_syscall_exit(AUDITSC_RESULT(regs->ax), - regs->ax); - /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only - * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is - * not used, entry.S will call us only on syscall exit, not - * entry; so when TIF_SYSCALL_AUDIT is used we must avoid - * calling send_sigtrap() on syscall entry. - * - * Note that when PTRACE_SYSEMU_SINGLESTEP is used, - * is_singlestep is false, despite his name, so we will still do - * the correct thing. - */ - else if (is_singlestep) - goto out; - } - - if (!(current->ptrace & PT_PTRACED)) - goto out; - - /* If a process stops on the 1st tracepoint with SYSCALL_TRACE - * and then is resumed with SYSEMU_SINGLESTEP, it will come in - * here. We have to check this and return */ - if (is_sysemu && entryexit) - return 0; - - /* Fake a debug trap */ - if (is_singlestep) - send_sigtrap(current, regs, 0); - - if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu) - goto out; - - /* the 0x80 provides a way for the tracing parent to distinguish - between a syscall stop and SIGTRAP delivery */ - /* Note that the debugger could change the result of test_thread_flag!*/ - 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; - } - ret = is_sysemu; -out: - if (unlikely(current->audit_context) && !entryexit) - audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax, - regs->bx, regs->cx, regs->dx, regs->si); - if (ret == 0) - return 0; - - regs->orig_ax = -1; /* force skip of syscall restarting */ - if (unlikely(current->audit_context)) - audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); - return 1; -} - -#else /* CONFIG_X86_64 */ - static void syscall_trace(struct pt_regs *regs) { + if (!(current->ptrace & PT_PTRACED)) + return; #if 0 printk("trace %s ip %lx sp %lx ax %d origrax %d caller %lx tiflags %x ptrace %x\n", @@ -1481,39 +1400,71 @@ static void syscall_trace(struct pt_regs *regs) } } -asmlinkage void syscall_trace_enter(struct pt_regs *regs) +#ifdef CONFIG_X86_32 +# define IS_IA32 1 +#elif defined CONFIG_IA32_EMULATION +# define IS_IA32 test_thread_flag(TIF_IA32) +#else +# define IS_IA32 0 +#endif + +/* + * We must return the syscall number to actually look up in the table. + * This can be -1L to skip running any syscall at all. + */ +asmregparm long syscall_trace_enter(struct pt_regs *regs) { + long ret = 0; + /* do the secure computing check first */ secure_computing(regs->orig_ax); - if (test_thread_flag(TIF_SYSCALL_TRACE) - && (current->ptrace & PT_PTRACED)) + if (unlikely(test_thread_flag(TIF_SYSCALL_EMU))) + ret = -1L; + + if (ret || test_thread_flag(TIF_SYSCALL_TRACE)) syscall_trace(regs); if (unlikely(current->audit_context)) { - if (test_thread_flag(TIF_IA32)) { + if (IS_IA32) audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax, regs->bx, regs->cx, regs->dx, regs->si); - } else { +#ifdef CONFIG_X86_64 + else audit_syscall_entry(AUDIT_ARCH_X86_64, regs->orig_ax, regs->di, regs->si, regs->dx, regs->r10); - } +#endif } + + return ret ?: regs->orig_ax; } -asmlinkage void syscall_trace_leave(struct pt_regs *regs) +asmregparm void syscall_trace_leave(struct pt_regs *regs) { if (unlikely(current->audit_context)) audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); - if ((test_thread_flag(TIF_SYSCALL_TRACE) - || test_thread_flag(TIF_SINGLESTEP)) - && (current->ptrace & PT_PTRACED)) + if (test_thread_flag(TIF_SYSCALL_TRACE)) syscall_trace(regs); -} -#endif /* CONFIG_X86_32 */ + /* + * If TIF_SYSCALL_EMU is set, we only get here because of + * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP). + * We already reported this syscall instruction in + * syscall_trace_enter(), so don't do any more now. + */ + if (unlikely(test_thread_flag(TIF_SYSCALL_EMU))) + return; + + /* + * If we are single-stepping, synthesize a trap to follow the + * system call instruction. + */ + if (test_thread_flag(TIF_SINGLESTEP) && + (current->ptrace & PT_PTRACED)) + send_sigtrap(current, regs, 0); +} diff --git a/include/asm-x86/calling.h b/include/asm-x86/calling.h index f13e62e..2bc162e 100644 --- a/include/asm-x86/calling.h +++ b/include/asm-x86/calling.h @@ -104,7 +104,7 @@ .endif .endm - .macro LOAD_ARGS offset + .macro LOAD_ARGS offset, skiprax=0 movq \offset(%rsp), %r11 movq \offset+8(%rsp), %r10 movq \offset+16(%rsp), %r9 @@ -113,7 +113,10 @@ movq \offset+48(%rsp), %rdx movq \offset+56(%rsp), %rsi movq \offset+64(%rsp), %rdi + .if \skiprax + .else movq \offset+72(%rsp), %rax + .endif .endm #define REST_SKIP 6*8 @@ -165,4 +168,3 @@ .macro icebp .byte 0xf1 .endm - diff --git a/include/asm-x86/ptrace-abi.h b/include/asm-x86/ptrace-abi.h index f224eb3..72e7b9d 100644 --- a/include/asm-x86/ptrace-abi.h +++ b/include/asm-x86/ptrace-abi.h @@ -73,11 +73,11 @@ #ifdef __x86_64__ # define PTRACE_ARCH_PRCTL 30 -#else -# define PTRACE_SYSEMU 31 -# define PTRACE_SYSEMU_SINGLESTEP 32 #endif +#define PTRACE_SYSEMU 31 +#define PTRACE_SYSEMU_SINGLESTEP 32 + #define PTRACE_SINGLEBLOCK 33 /* resume execution until next branch */ #ifndef __ASSEMBLY__ diff --git a/include/asm-x86/thread_info.h b/include/asm-x86/thread_info.h index fb8d3cd..b2702a1 100644 --- a/include/asm-x86/thread_info.h +++ b/include/asm-x86/thread_info.h @@ -75,9 +75,7 @@ struct thread_info { #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/ #define TIF_IRET 5 /* force IRET */ -#ifdef CONFIG_X86_32 #define TIF_SYSCALL_EMU 6 /* syscall emulation active */ -#endif #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ #define TIF_SECCOMP 8 /* secure computing */ #define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */ @@ -100,11 +98,7 @@ struct thread_info { #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_IRET (1 << TIF_IRET) -#ifdef CONFIG_X86_32 #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU) -#else -#define _TIF_SYSCALL_EMU 0 -#endif #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) #define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY) @@ -121,11 +115,20 @@ struct thread_info { #define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR) #define _TIF_BTS_TRACE_TS (1 << TIF_BTS_TRACE_TS) +/* work to do in syscall_trace_enter() */ +#define _TIF_WORK_SYSCALL_ENTRY \ + (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | \ + _TIF_SYSCALL_AUDIT | _TIF_SECCOMP) + +/* work to do in syscall_trace_leave() */ +#define _TIF_WORK_SYSCALL_EXIT \ + (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP) + /* work to do on interrupt/exception return */ #define _TIF_WORK_MASK \ (0x0000FFFF & \ ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \ - _TIF_SECCOMP|_TIF_SYSCALL_EMU)) + _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU)) /* work to do on any return to user space */ #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP) |
