-----Original Message-----
> Hi Tao Liu,
>
> Thanks for the update.
>
> -----Original Message-----
> > This patch indroduces mod_symname_hash, and its install/remove operations.
> > Since symbol_search() has to return the lowest address symbol and
> > symbol_search_next() returns the next lowest symbol, thus the installation
> > should be sorted ascendingly.
> >
> > Install spn previous to sp:
> >
> > If sp is the start of bucket, and
> > 1) spn->value is smaller than sp->value, or
> > 2) spn->value equals sp->value and spn is smaller than sp.
> >
> > Install spn next to sp:
> >
> > 1) spn->value is larger than sp->value, or
> > 2) spn->value equals to sp->value and spn is larger than sp,
> > spn will stay behind of sp. And if
> > 1) sp->name_hash_next is NULL or
> > 2) sp->name_hash_next->value larger than spn->value
> > spn will be next to sp.
> >
> > spn->value is the kernel address of the symbol and will not change.
> > So we use it mainly to determine the sequence. When spn->value equals
> > sp->value, they must be symbols within a kernel module, so we use spn
> > and sp to determine the sequence.
>
> If sp->value equals to spn->value, they are in the same module, and
> spn should be larger than sp, according to mod_symtable_hash_install_range().
> Then is it OK to insert spn when sp->value becomes larger than spn->value
> like this?
>
> sp = st->mod_symname_hash[index];
> if (!sp) {
> st->mod_symname_hash[index] = spn;
> spn->name_hash_next = NULL;
> return;
> }
> for (; sp; sp = sp->name_hash_next) {
> if (sp->value > spn->value || !sp->name_hash_next) {
> spn->name_hash_next = sp->name_hash_next;
> sp->name_hash_next = spn;
> return;
> }
> }
sorry, I was confused, this is a fixed one:
sp = st->mod_symname_hash[index];
if (!sp || sp->value > spn->value) {
spn->name_hash_next = sp;
st->mod_symname_hash[index] = spn;
return;
}
for (; sp; sp = sp->name_hash_next) {
if (!sp->name_hash_next || sp->name_hash_next->value > spn->value) {
spn->name_hash_next = sp->name_hash_next;
sp->name_hash_next = spn;
return;
}
}
Thanks,
Kazu
>
> >
> > Signed-off-by: Tao Liu <ltao@xxxxxxxxxx>
> > ---
> > defs.h | 1 +
> > symbols.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 82 insertions(+)
> >
> > diff --git a/defs.h b/defs.h
> > index cbd45e5..bbdca79 100644
> > --- a/defs.h
> > +++ b/defs.h
> > @@ -2755,6 +2755,7 @@ struct symbol_table_data {
> > double val_hash_searches;
> > double val_hash_iterations;
> > struct syment *symname_hash[SYMNAME_HASH];
> > + struct syment *mod_symname_hash[SYMNAME_HASH];
> > struct symbol_namespace kernel_namespace;
> > struct syment *ext_module_symtable;
> > struct syment *ext_module_symend;
> > diff --git a/symbols.c b/symbols.c
> > index 69dccdb..7fb2df7 100644
> > --- a/symbols.c
> > +++ b/symbols.c
> > @@ -1157,6 +1157,87 @@ symname_hash_install(struct syment *spn)
> > }
> > }
> >
> > +/*
> > + * Install a single kernel module symbol into the mod_symname_hash.
> > + */
> > +static void
> > +mod_symname_hash_install(struct syment *spn)
> > +{
> > + struct syment *sp, *tmp;
> > + int index;
> > +
> > + if (!spn)
> > + return;
> > +
> > + index = SYMNAME_HASH_INDEX(spn->name);
> > +
> > + sp = st->mod_symname_hash[index];
> > +
> > + if (!sp ||
> > + (spn->value < sp->value) ||
> > + (spn->value == sp->value && spn < sp)) {
> > + /*
> > + * Install spn to the previous position of sp.
> > + */
> > + st->mod_symname_hash[index] = spn;
> > + spn->name_hash_next = sp;
> > + } else {
> > + for (; sp; sp = sp->name_hash_next) {
> > + if ((spn->value > sp->value) ||
> > + (spn->value == sp->value && spn > sp)) {
> > + if (!sp->name_hash_next ||
> > + spn->value < sp->name_hash_next->value) {
> > + /*
> > + * Install spn to the next position of sp.
> > + */
> > + tmp = sp->name_hash_next;
> > + sp->name_hash_next = spn;
> > + spn->name_hash_next = tmp;
> > + break;
> > + }
> > + }
> > + }
> > + }
> > +}
> > +
> > +static void
> > +mod_symname_hash_remove(struct syment *spn)
> > +{
> > + struct syment *sp;
> > + int index;
> > +
> > + if (!spn)
> > + return;
> > +
> > + index = SYMNAME_HASH_INDEX(spn->name);
> > +
> > + if (st->mod_symname_hash[index] == spn)
> > + st->mod_symname_hash[index] = spn->name_hash_next;
>
> I think now we can return here,
>
> > +
> > + for (sp = st->mod_symname_hash[index]; sp; sp = sp->name_hash_next) {
> > + if (sp->name_hash_next == spn)
> > + sp->name_hash_next = spn->name_hash_next;
>
> and here, too.
>
> For the other patches, please wait for a while.
>
> Thanks,
> Kazu
>
>
> > + }
> > +}
> > +
> > +static void
> > +mod_symtable_hash_install_range(struct syment *from, struct syment *to)
> > +{
> > + struct syment *sp;
> > +
> > + for (sp = from; sp <= to; sp++)
> > + mod_symname_hash_install(sp);
> > +}
> > +
> > +static void
> > +mod_symtable_hash_remove_range(struct syment *from, struct syment *to)
> > +{
> > + struct syment *sp;
> > +
> > + for (sp = from; sp <= to; sp++)
> > + mod_symname_hash_remove(sp);
> > +}
> > +
> > /*
> > * Static kernel symbol value search
> > */
> > --
> > 2.29.2
>
>
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