diff options
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/debug-monitors.c | 48 | ||||
| -rw-r--r-- | arch/arm64/kernel/head.S | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/image.h | 41 | ||||
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 17 | ||||
| -rw-r--r-- | arch/arm64/kernel/traps.c | 11 |
5 files changed, 71 insertions, 51 deletions
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index 8aee3aeec3e6..c536c9e307b9 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -226,11 +226,28 @@ static int call_step_hook(struct pt_regs *regs, unsigned int esr) return retval; } +static void send_user_sigtrap(int si_code) +{ + struct pt_regs *regs = current_pt_regs(); + siginfo_t info = { + .si_signo = SIGTRAP, + .si_errno = 0, + .si_code = si_code, + .si_addr = (void __user *)instruction_pointer(regs), + }; + + if (WARN_ON(!user_mode(regs))) + return; + + if (interrupts_enabled(regs)) + local_irq_enable(); + + force_sig_info(SIGTRAP, &info, current); +} + static int single_step_handler(unsigned long addr, unsigned int esr, struct pt_regs *regs) { - siginfo_t info; - /* * If we are stepping a pending breakpoint, call the hw_breakpoint * handler first. @@ -239,11 +256,7 @@ static int single_step_handler(unsigned long addr, unsigned int esr, return 0; if (user_mode(regs)) { - info.si_signo = SIGTRAP; - info.si_errno = 0; - info.si_code = TRAP_HWBKPT; - info.si_addr = (void __user *)instruction_pointer(regs); - force_sig_info(SIGTRAP, &info, current); + send_user_sigtrap(TRAP_HWBKPT); /* * ptrace will disable single step unless explicitly @@ -307,17 +320,8 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr) static int brk_handler(unsigned long addr, unsigned int esr, struct pt_regs *regs) { - siginfo_t info; - if (user_mode(regs)) { - info = (siginfo_t) { - .si_signo = SIGTRAP, - .si_errno = 0, - .si_code = TRAP_BRKPT, - .si_addr = (void __user *)instruction_pointer(regs), - }; - - force_sig_info(SIGTRAP, &info, current); + send_user_sigtrap(TRAP_BRKPT); } else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) { pr_warning("Unexpected kernel BRK exception at EL1\n"); return -EFAULT; @@ -328,7 +332,6 @@ static int brk_handler(unsigned long addr, unsigned int esr, int aarch32_break_handler(struct pt_regs *regs) { - siginfo_t info; u32 arm_instr; u16 thumb_instr; bool bp = false; @@ -359,14 +362,7 @@ int aarch32_break_handler(struct pt_regs *regs) if (!bp) return -EFAULT; - info = (siginfo_t) { - .si_signo = SIGTRAP, - .si_errno = 0, - .si_code = TRAP_BRKPT, - .si_addr = pc, - }; - - force_sig_info(SIGTRAP, &info, current); + send_user_sigtrap(TRAP_BRKPT); return 0; } diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index ffe9c2b6431b..917d98108b3f 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -514,9 +514,14 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems #endif /* EL2 debug */ + mrs x0, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer + sbfx x0, x0, #8, #4 + cmp x0, #1 + b.lt 4f // Skip if no PMU present mrs x0, pmcr_el0 // Disable debug access traps ubfx x0, x0, #11, #5 // to EL2 and allow access to msr mdcr_el2, x0 // all PMU counters from EL1 +4: /* Stage-2 translation */ msr vttbr_el2, xzr diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h index bc2abb8b1599..352f7abd91c9 100644 --- a/arch/arm64/kernel/image.h +++ b/arch/arm64/kernel/image.h @@ -65,6 +65,16 @@ #ifdef CONFIG_EFI /* + * Prevent the symbol aliases below from being emitted into the kallsyms + * table, by forcing them to be absolute symbols (which are conveniently + * ignored by scripts/kallsyms) rather than section relative symbols. + * The distinction is only relevant for partial linking, and only for symbols + * that are defined within a section declaration (which is not the case for + * the definitions below) so the resulting values will be identical. + */ +#define KALLSYMS_HIDE(sym) ABSOLUTE(sym) + +/* * The EFI stub has its own symbol namespace prefixed by __efistub_, to * isolate it from the kernel proper. The following symbols are legally * accessed by the stub, so provide some aliases to make them accessible. @@ -73,25 +83,26 @@ * linked at. The routines below are all implemented in assembler in a * position independent manner */ -__efistub_memcmp = __pi_memcmp; -__efistub_memchr = __pi_memchr; -__efistub_memcpy = __pi_memcpy; -__efistub_memmove = __pi_memmove; -__efistub_memset = __pi_memset; -__efistub_strlen = __pi_strlen; -__efistub_strcmp = __pi_strcmp; -__efistub_strncmp = __pi_strncmp; -__efistub___flush_dcache_area = __pi___flush_dcache_area; +__efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp); +__efistub_memchr = KALLSYMS_HIDE(__pi_memchr); +__efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy); +__efistub_memmove = KALLSYMS_HIDE(__pi_memmove); +__efistub_memset = KALLSYMS_HIDE(__pi_memset); +__efistub_strlen = KALLSYMS_HIDE(__pi_strlen); +__efistub_strnlen = KALLSYMS_HIDE(__pi_strnlen); +__efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp); +__efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp); +__efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area); #ifdef CONFIG_KASAN -__efistub___memcpy = __pi_memcpy; -__efistub___memmove = __pi_memmove; -__efistub___memset = __pi_memset; +__efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy); +__efistub___memmove = KALLSYMS_HIDE(__pi_memmove); +__efistub___memset = KALLSYMS_HIDE(__pi_memset); #endif -__efistub__text = _text; -__efistub__end = _end; -__efistub__edata = _edata; +__efistub__text = KALLSYMS_HIDE(_text); +__efistub__end = KALLSYMS_HIDE(_end); +__efistub__edata = KALLSYMS_HIDE(_edata); #endif diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 4fad9787ab46..d9751a4769e7 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -44,14 +44,13 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) unsigned long irq_stack_ptr; /* - * Use raw_smp_processor_id() to avoid false-positives from - * CONFIG_DEBUG_PREEMPT. get_wchan() calls unwind_frame() on sleeping - * task stacks, we can be pre-empted in this case, so - * {raw_,}smp_processor_id() may give us the wrong value. Sleeping - * tasks can't ever be on an interrupt stack, so regardless of cpu, - * the checks will always fail. + * Switching between stacks is valid when tracing current and in + * non-preemptible context. */ - irq_stack_ptr = IRQ_STACK_PTR(raw_smp_processor_id()); + if (tsk == current && !preemptible()) + irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id()); + else + irq_stack_ptr = 0; low = frame->sp; /* irq stacks are not THREAD_SIZE aligned */ @@ -64,8 +63,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) return -EINVAL; frame->sp = fp + 0x10; - frame->fp = *(unsigned long *)(fp); - frame->pc = *(unsigned long *)(fp + 8); + frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); + frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8)); #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (tsk && tsk->ret_stack && diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index cbedd724f48e..c5392081b49b 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -146,9 +146,18 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { struct stackframe frame; - unsigned long irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id()); + unsigned long irq_stack_ptr; int skip; + /* + * Switching between stacks is valid when tracing current and in + * non-preemptible context. + */ + if (tsk == current && !preemptible()) + irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id()); + else + irq_stack_ptr = 0; + pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); if (!tsk) |