On Fri, Feb 17, 2023 at 09:31:48PM +0100, Ahmad Fatoum wrote:
> For debugging, it can be useful to disable a fixup to rule out it causing
> issues. For platforms supporting kallsyms, we can readily allow enabling
> and disabling fixups by name, so let's add a command that does just that.
>
> Suggested-by: Daniel Brát <danek.brat@xxxxxxxxx>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
> commands/Kconfig | 15 ++++++++
> commands/Makefile | 1 +
> commands/of_fixup.c | 86 +++++++++++++++++++++++++++++++++++++++++++++
> common/kallsyms.c | 8 ++---
> common/oftree.c | 17 +++++----
> drivers/of/Kconfig | 6 ++++
> include/kallsyms.h | 4 +++
> include/of.h | 10 ++++++
> 8 files changed, 137 insertions(+), 10 deletions(-)
> create mode 100644 commands/of_fixup.c
>
> +static int do_of_fixup(int argc, char *argv[])
> +{
> + struct of_fixup *of_fixup;
> + int opt, enable = -1;
> +
> + while ((opt = getopt(argc, argv, "ed")) > 0) {
> + switch (opt) {
> + case 'e':
> + enable = 1;
> + break;
> + case 'd':
> + enable = 0;
> + break;
> + default:
> + return COMMAND_ERROR_USAGE;
> + }
> + }
> +
> + argv += optind;
> + argc -= optind;
> +
> + if ((enable < 0 && argc > 0) || (enable >= 0 && argc == 0))
> + return COMMAND_ERROR_USAGE;
> +
> + list_for_each_entry(of_fixup, &of_fixup_list, list) {
> + int i;
> + ulong addr = (ulong)of_fixup->fixup;
> + char sym[KSYM_SYMBOL_LEN];
> + const char *name;
> +
> + name = kallsyms_lookup(addr, NULL, NULL, NULL, sym);
> + if (!name) {
> + sprintf(sym, "<0x%lx>", addr);
> + name = sym;
> + }
Does this fallback make sense? kallsyms_lookup() should always return a
name, otherwise something is really wrong.
> +
> + if (enable == -1) {
> + printf("%s(0x%p)%s\n", name, of_fixup->context,
> + of_fixup->disabled ? " [DISABELD]" : "");
s/DISABELD/DISABLED/
We can have the same fixup function with different contexts, that's why
you print the context pointer here. Shouldn't we then have a way to
disable a specific fixup, like "of_fixup -d mtd_partition_fixup(0x2fed7a00)"?
Sascha
> +config OF_FIXUP_TOGGLE
> + bool
> + help
> + This is selected when some device tree fixups may be selectively
> + disabled.
Why does this have an extra config option? It doesn't look like it's
saving a lot of binary space.
Sascha
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