lkml.org 
[lkml]   [2022]   [Mar]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v9 02/11] fprobe: Add ftrace based probe APIs
On Sun, Mar 06, 2022 at 06:36:03PM +0900, Masami Hiramatsu wrote:

SNIP

> +}
> +NOKPROBE_SYMBOL(fprobe_handler);
> +
> +/* Convert ftrace location address from symbols */
> +static unsigned long *get_ftrace_locations(const char **syms, int num)
> +{
> + unsigned long addr, size;
> + unsigned long *addrs;
> + int i;
> +
> + /* Convert symbols to symbol address */
> + addrs = kcalloc(num, sizeof(*addrs), GFP_KERNEL);
> + if (!addrs)
> + return ERR_PTR(-ENOMEM);
> +
> + for (i = 0; i < num; i++) {
> + addrs[i] = kallsyms_lookup_name(syms[i]);
> + if (!addrs[i]) /* Maybe wrong symbol */
> + goto error;
> + }
> +
> + /* Convert symbol address to ftrace location. */
> + for (i = 0; i < num; i++) {
> + if (!kallsyms_lookup_size_offset(addrs[i], &size, NULL) || !size)
> + goto error;
> + addr = ftrace_location_range(addrs[i], addrs[i] + size - 1);
> + if (!addr) /* No dynamic ftrace there. */
> + goto error;
> + addrs[i] = addr;
> + }

why not one just single loop ?

jirka


> +
> + return addrs;
> +
> +error:
> + kfree(addrs);
> +
> + return ERR_PTR(-ENOENT);
> +}
> +
> +static void fprobe_init(struct fprobe *fp)
> +{
> + fp->nmissed = 0;
> + fp->ops.func = fprobe_handler;
> + fp->ops.flags |= FTRACE_OPS_FL_SAVE_REGS;
> +}

SNIP

\
 
 \ /
  Last update: 2022-03-07 13:59    [W:0.089 / U:0.324 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site