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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-06 20:32:34 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-06 20:32:34 +0300 |
commit | 7782aae498b92f124267b366293100d121fe0f56 (patch) | |
tree | 70ca107257d0ddcfa4d7cfe559012f5b650f7ace /arch/arm/kernel | |
parent | 833477fce7a14d43ae4c07f8ddc32fa5119471a2 (diff) | |
parent | e66372ecb80dc5179c7abb880229c7452e813d15 (diff) | |
download | linux-7782aae498b92f124267b366293100d121fe0f56.tar.xz |
Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King:
- Print an un-hashed userspace PC on undefined instruction exception
- Disable FDPIC ABI
- Remove redundant vfp_flush/release_thread functions
- Use raw_cpu_* rather than this_cpu_* in handle_bad_stack()
- Avoid needlessly long backtraces when show_regs() is called
- Fix an issue with stack traces through call_with_stack()
- Avoid stack traces saving a duplicate exception PC value
- Pass a void pointer to virt_to_page() in DMA mapping code
- Fix kasan maps for modules when CONFIG_KASAN_VMALLOC=n
- Show FDT region and page table level names in kernel page tables dump
* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 9246/1: dump: show page table level name
ARM: 9245/1: dump: show FDT region
ARM: 9242/1: kasan: Only map modules if CONFIG_KASAN_VMALLOC=n
ARM: 9240/1: dma-mapping: Pass (void *) to virt_to_page()
ARM: 9234/1: stacktrace: Avoid duplicate saving of exception PC value
ARM: 9233/1: stacktrace: Skip frame pointer boundary check for call_with_stack()
ARM: 9224/1: Dump the stack traces based on the parameter 'regs' of show_regs()
ARM: 9232/1: Replace this_cpu_* with raw_cpu_* in handle_bad_stack()
ARM: 9228/1: vfp: kill vfp_flush/release_thread()
ARM: 9226/1: disable FDPIC ABI
ARM: 9221/1: traps: print un-hashed user pc on undefined instruction
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/process.c | 2 | ||||
-rw-r--r-- | arch/arm/kernel/return_address.c | 1 | ||||
-rw-r--r-- | arch/arm/kernel/stacktrace.c | 84 | ||||
-rw-r--r-- | arch/arm/kernel/traps.c | 14 |
4 files changed, 72 insertions, 29 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 3d9cace63884..96f3fbd51764 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -201,7 +201,7 @@ void __show_regs(struct pt_regs *regs) void show_regs(struct pt_regs * regs) { __show_regs(regs); - dump_stack(); + dump_backtrace(regs, NULL, KERN_DEFAULT); } ATOMIC_NOTIFIER_HEAD(thread_notify_head); diff --git a/arch/arm/kernel/return_address.c b/arch/arm/kernel/return_address.c index 8aac1e10b117..38f1ea9c724d 100644 --- a/arch/arm/kernel/return_address.c +++ b/arch/arm/kernel/return_address.c @@ -47,6 +47,7 @@ here: frame.kr_cur = NULL; frame.tsk = current; #endif + frame.ex_frame = false; walk_stackframe(&frame, save_return_addr, &data); diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index d0fa2037460a..85443b5d1922 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -9,6 +9,8 @@ #include <asm/stacktrace.h> #include <asm/traps.h> +#include "reboot.h" + #if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) /* * Unwind the current stack frame and store the new register values in the @@ -39,29 +41,74 @@ * Note that with framepointer enabled, even the leaf functions have the same * prologue and epilogue, therefore we can ignore the LR value in this case. */ -int notrace unwind_frame(struct stackframe *frame) + +extern unsigned long call_with_stack_end; + +static int frame_pointer_check(struct stackframe *frame) { unsigned long high, low; unsigned long fp = frame->fp; + unsigned long pc = frame->pc; + + /* + * call_with_stack() is the only place we allow SP to jump from one + * stack to another, with FP and SP pointing to different stacks, + * skipping the FP boundary check at this point. + */ + if (pc >= (unsigned long)&call_with_stack && + pc < (unsigned long)&call_with_stack_end) + return 0; /* only go to a higher address on the stack */ low = frame->sp; high = ALIGN(low, THREAD_SIZE); -#ifdef CONFIG_CC_IS_CLANG /* check current frame pointer is within bounds */ +#ifdef CONFIG_CC_IS_CLANG if (fp < low + 4 || fp > high - 4) return -EINVAL; - - frame->sp = frame->fp; - frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); - frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 4)); #else - /* check current frame pointer is within bounds */ if (fp < low + 12 || fp > high - 4) return -EINVAL; +#endif + + return 0; +} + +int notrace unwind_frame(struct stackframe *frame) +{ + unsigned long fp = frame->fp; + + if (frame_pointer_check(frame)) + return -EINVAL; + + /* + * When we unwind through an exception stack, include the saved PC + * value into the stack trace. + */ + if (frame->ex_frame) { + struct pt_regs *regs = (struct pt_regs *)frame->sp; + + /* + * We check that 'regs + sizeof(struct pt_regs)' (that is, + * ®s[1]) does not exceed the bottom of the stack to avoid + * accessing data outside the task's stack. This may happen + * when frame->ex_frame is a false positive. + */ + if ((unsigned long)®s[1] > ALIGN(frame->sp, THREAD_SIZE)) + return -EINVAL; + + frame->pc = regs->ARM_pc; + frame->ex_frame = false; + return 0; + } /* restore the registers from the stack frame */ +#ifdef CONFIG_CC_IS_CLANG + frame->sp = frame->fp; + frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); + frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 4)); +#else frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp - 12)); frame->sp = READ_ONCE_NOCHECK(*(unsigned long *)(fp - 8)); frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp - 4)); @@ -72,6 +119,9 @@ int notrace unwind_frame(struct stackframe *frame) (void *)frame->fp, &frame->kr_cur); #endif + if (in_entry_text(frame->pc)) + frame->ex_frame = true; + return 0; } #endif @@ -102,7 +152,6 @@ static int save_trace(struct stackframe *frame, void *d) { struct stack_trace_data *data = d; struct stack_trace *trace = data->trace; - struct pt_regs *regs; unsigned long addr = frame->pc; if (data->no_sched_functions && in_sched_functions(addr)) @@ -113,19 +162,6 @@ static int save_trace(struct stackframe *frame, void *d) } trace->entries[trace->nr_entries++] = addr; - - if (trace->nr_entries >= trace->max_entries) - return 1; - - if (!in_entry_text(frame->pc)) - return 0; - - regs = (struct pt_regs *)frame->sp; - if ((unsigned long)®s[1] > ALIGN(frame->sp, THREAD_SIZE)) - return 0; - - trace->entries[trace->nr_entries++] = regs->ARM_pc; - return trace->nr_entries >= trace->max_entries; } @@ -167,6 +203,9 @@ here: frame.kr_cur = NULL; frame.tsk = tsk; #endif +#ifdef CONFIG_UNWINDER_FRAME_POINTER + frame.ex_frame = false; +#endif walk_stackframe(&frame, save_trace, &data); } @@ -188,6 +227,9 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) frame.kr_cur = NULL; frame.tsk = current; #endif +#ifdef CONFIG_UNWINDER_FRAME_POINTER + frame.ex_frame = in_entry_text(frame.pc); +#endif walk_stackframe(&frame, save_trace, &data); } diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 9283dc65be31..20b2db6dcd1c 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -205,14 +205,14 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) } #ifdef CONFIG_ARM_UNWIND -static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, - const char *loglvl) +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl) { unwind_backtrace(regs, tsk, loglvl); } #else -static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, - const char *loglvl) +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl) { unsigned int fp, mode; int ok = 1; @@ -487,7 +487,7 @@ asmlinkage void do_undefinstr(struct pt_regs *regs) die_sig: #ifdef CONFIG_DEBUG_USER if (user_debug & UDBG_UNDEFINED) { - pr_info("%s (%d): undefined instruction: pc=%p\n", + pr_info("%s (%d): undefined instruction: pc=%px\n", current->comm, task_pid_nr(current), pc); __show_regs(regs); dump_instr(KERN_INFO, regs); @@ -920,9 +920,9 @@ asmlinkage void handle_bad_stack(struct pt_regs *regs) { unsigned long tsk_stk = (unsigned long)current->stack; #ifdef CONFIG_IRQSTACKS - unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr); + unsigned long irq_stk = (unsigned long)raw_cpu_read(irq_stack_ptr); #endif - unsigned long ovf_stk = (unsigned long)this_cpu_read(overflow_stack_ptr); + unsigned long ovf_stk = (unsigned long)raw_cpu_read(overflow_stack_ptr); console_verbose(); pr_emerg("Insufficient stack space to handle exception!"); |