Hi Song,
On Mon, 5 Dec 2022 16:29:54 +0800
Song Chen <chensong_2000@xxxxxx> wrote:
> @@ -112,4 +112,133 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base)
> return ret;
> }
>
> +static nokprobe_inline int
> +probe_mem_read_user(void *dest, void *src, size_t size)
> +{
> + const void __user *uaddr = (__force const void __user *)src;
> +
> + return copy_from_user_nofault(dest, uaddr, size);
> +}
> +
> +static nokprobe_inline int
> +probe_mem_read(void *dest, void *src, size_t size)
> +{
> +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
> + if ((unsigned long)src < TASK_SIZE)
> + return probe_mem_read_user(dest, src, size);
> +#endif
> + return copy_from_kernel_nofault(dest, src, size);
> +}
> +
So, the error which kernel build bot found has been introduced by this patch.
The easiest acceptable change will add
#ifdef CONFIG_HAVE_REGS_AND_STACK_ACCESS_API
here, and #endif after process_fetch_insn().
Thank you,
> +static nokprobe_inline unsigned long
> +get_event_field(struct fetch_insn *code, void *rec)
> +{
> + struct ftrace_event_field *field = code->data;
> + unsigned long val;
> + void *addr;
> +
> + addr = rec + field->offset;
> +
> + if (is_string_field(field)) {
> + switch (field->filter_type) {
> + case FILTER_DYN_STRING:
> + val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff));
> + break;
> + case FILTER_RDYN_STRING:
> + val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff));
> + break;
> + case FILTER_STATIC_STRING:
> + val = (unsigned long)addr;
> + break;
> + case FILTER_PTR_STRING:
> + val = (unsigned long)(*(char *)addr);
> + break;
> + default:
> + WARN_ON_ONCE(1);
> + return 0;
> + }
> + return val;
> + }
> +
> + switch (field->size) {
> + case 1:
> + if (field->is_signed)
> + val = *(char *)addr;
> + else
> + val = *(unsigned char *)addr;
> + break;
> + case 2:
> + if (field->is_signed)
> + val = *(short *)addr;
> + else
> + val = *(unsigned short *)addr;
> + break;
> + case 4:
> + if (field->is_signed)
> + val = *(int *)addr;
> + else
> + val = *(unsigned int *)addr;
> + break;
> + default:
> + if (field->is_signed)
> + val = *(long *)addr;
> + else
> + val = *(unsigned long *)addr;
> + break;
> + }
> + return val;
> +}
> +
> +/* Note that we don't verify it, since the code does not come from user space */
> +static int
> +process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
> + void *base)
> +{
> + struct pt_regs *regs = rec;
> + unsigned long val;
> +
> +retry:
> + /* 1st stage: get value from context */
> + switch (code->op) {
> + case FETCH_OP_REG:
> + val = regs_get_register(regs, code->param);
> + break;
> + case FETCH_OP_STACK:
> + val = regs_get_kernel_stack_nth(regs, code->param);
> + break;
> + case FETCH_OP_STACKP:
> + val = kernel_stack_pointer(regs);
> + break;
> + case FETCH_OP_RETVAL:
> + val = regs_return_value(regs);
> + break;
> + case FETCH_OP_IMM:
> + val = code->immediate;
> + break;
> + case FETCH_OP_COMM:
> + val = (unsigned long)current->comm;
> + break;
> + case FETCH_OP_DATA:
> + val = (unsigned long)code->data;
> + break;
> +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
> + case FETCH_OP_ARG:
> + val = regs_get_kernel_argument(regs, code->param);
> + break;
> +#endif
> + case FETCH_NOP_SYMBOL: /* Ignore a place holder */
> + code++;
> + goto retry;
> + case FETCH_OP_TP_ARG:
> + val = get_event_field(code, rec);
> + break;
> + default:
> + return -EILSEQ;
> + }
> + code++;
> +
> + return process_fetch_insn_bottom(code, val, dest, base);
> +}
> +NOKPROBE_SYMBOL(process_fetch_insn)
> +
> #endif /* __TRACE_PROBE_KERNEL_H_ */
> --
> 2.25.1
>
--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
