Re: [PATCH 1/2] kallsyms: Allow kernel symbols in L1 to be found inBlackfin architecture

From: Andrew Morton
Date: Tue Apr 29 2008 - 18:06:44 EST


On Fri, 25 Apr 2008 18:28:18 +0800
Bryan Wu <cooloney@xxxxxxxxxx> wrote:

> From: Robin Getz <robin.getz@xxxxxxxxxx>
>
> Add _stext_l1, _etext_l1 for the L1 memory section in Blackfin.
>
> Signed-off-by: Robin Getz <robin.getz@xxxxxxxxxx>
> Signed-off-by: Bryan Wu <cooloney@xxxxxxxxxx>
> ---
> kernel/kallsyms.c | 6 +++++-
> scripts/kallsyms.c | 8 +++++++-
> 2 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
> index f091d13..456d1f6 100644
> --- a/kernel/kallsyms.c
> +++ b/kernel/kallsyms.c
> @@ -55,7 +55,11 @@ static inline int is_kernel_inittext(unsigned long addr)
>
> static inline int is_kernel_text(unsigned long addr)
> {
> - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext)
> + if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext)
> +#if defined(CONFIG_BLACKFIN)
> + || (addr >= (unsigned long)_stext_l1 && addr <= (unsigned long)_etext_l1)
> +#endif
> + )

That's a bit grubby. I suppose we could pretend not to have noticed, but
this really isn't the preferred way of putting arch-specific hooks into
arch-neutral code.

Nicer might be to add

void __weak arch_is_kernel_text(unsigned long addr)
{
return 0;
}

with a declaration in linux/kallsyms.h and then override
arch_is_kernel_text() in arch/blackfin/ code.


> return 1;
> return in_gate_area_no_task(addr);
> }
> diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
> index c912137..0f7269f 100644
> --- a/scripts/kallsyms.c
> +++ b/scripts/kallsyms.c
> @@ -41,6 +41,7 @@ struct sym_entry {
> static struct sym_entry *table;
> static unsigned int table_size, table_cnt;
> static unsigned long long _text, _stext, _etext, _sinittext, _einittext;
> +static unsigned long long _stext_l1, _etext_l1;
> static int all_symbols = 0;
> static char symbol_prefix_char = '\0';
>
> @@ -98,6 +99,10 @@ static int read_symbol(FILE *in, struct sym_entry *s)
> _sinittext = s->addr;
> else if (strcmp(sym, "_einittext") == 0)
> _einittext = s->addr;
> + else if (strcmp(sym, "_stext_l1" ) == 0)
^ stray space
^ and another one

> + _stext_l1 = s->addr;
> + else if (strcmp(sym, "_etext_l1" ) == 0)
> + _etext_l1 = s->addr;
> else if (toupper(stype) == 'A')
> {
> /* Keep these useful absolute symbols */
> @@ -160,7 +165,8 @@ static int symbol_valid(struct sym_entry *s)
> * and inittext sections are discarded */
> if (!all_symbols) {
> if ((s->addr < _stext || s->addr > _etext)
> - && (s->addr < _sinittext || s->addr > _einittext))
> + && (s->addr < _sinittext || s->addr > _einittext)
> + && (s->addr < _stext_l1 || s->addr > _etext_l1))

so... for non-blackfin, the above addition is equivalent to

&& (s->addr < 0 || s->addr > 0)

which is always true, except for s->addr==0, in which case we just broke
it.

I guess addr==0 isn't an interesting case here.


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