Re: [PATCH] call sysrq_timer_list_show from a workqueue

Rusty Russell
2008-01-09T03:20:37Z

On Wednesday 09 January 2008 11:21:59 Andrew Morton wrote:
> The string handling in here has become a bit scruffy.

Yes, that patch also evokes a const warning. Fixed below. I assume you've
queued these because you're thinking of applying them before 2.6.24? I'd say
only modules-de-mutex-more-symbol-lookup-paths-in-the-module-code.patch
warrants that (the other is unlikely and not a regression).

> afacit the `namebuf[KSYM_NAME_LEN - 1] = 0;' would be unneeded if we were
> to use strlcpy() and I suspect the `namebuf[0] = 0;' isn't needed either.
>
> And the use of strlcpy() means we don't need to subtract 1 from
> KSYM_NAME_LEN and we don't need to fret about weird strncpy semantics when
> the input string is too large.
>
>
> And the fact that incoming arg `namebuf' MUST point at a
> KSYM_NAME_LEN-sized buffer could be better communicated by using a
> dedicated struct for this, or by giving the arg a type of `char
> namebuf[KSYM_NAME_LEN]'. Or by adding a comment. Or by just ignoring
> me and doing something more useful.

Or better, rework all the name lookup interfaces, rather than having:

struct module *module_text_address(unsigned long addr);
struct module *__module_text_address(unsigned long addr);
int is_module_address(unsigned long addr);
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
char *name, char *module_name, int *exported);
char *module_address_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname,
char *namebuf);
int lookup_module_symbol_name(unsigned long addr, char *symname);
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
unsigned long *offset, char *modname, char *name);
unsigned long module_kallsyms_lookup_name(const char *name);

unsigned long kallsyms_lookup_name(const char *name);
extern int kallsyms_lookup_size_offset(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset);
const char *kallsyms_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname, char *namebuf);
extern int sprint_symbol(char *buffer, unsigned long address);
extern void __print_symbol(const char *fmt, unsigned long address);
int lookup_symbol_name(unsigned long addr, char *symname);
int lookup_symbol_attrs(unsigned long addr, unsigned long *size,
unsigned long *offset, char *modname, char *name);

Cheers,
Rusty.