Hi Tao, On Sat, 18 Sep 2021 15:59:32 +0800 Tao Liu <[email protected]> wrote:
> symname_hash_install won't check if spn has been installed before. If > it does, the second install will corrupt the hash table as well as > spn->cnt counting. This patch adds the check to avoid such risks. > > Signed-off-by: Tao Liu <[email protected]> > --- > symbols.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/symbols.c b/symbols.c > index f7157b1..6d12c55 100644 > --- a/symbols.c > +++ b/symbols.c > @@ -1147,6 +1147,20 @@ mod_symtable_hash_remove_range(struct syment *from, > struct syment *to) > symname_hash_remove(st->mod_symname_hash, sp); > } > > +static inline int > +syment_is_installed(struct syment *table[], struct syment *spn) > +{ > + struct syment *sp; > + int index; > + > + index = SYMNAME_HASH_INDEX(spn->name); > + for (sp = table[index]; sp; sp = sp->name_hash_next) { > + if (sp == spn) > + return TRUE; > + } > + return FALSE; > +} > + > /* > * Install a single static kernel symbol into the symname_hash. > */ > @@ -1156,7 +1170,7 @@ symname_hash_install(struct syment *table[], struct > syment *spn) > struct syment *sp; > int index; > > - if (!spn) > + if (!spn || syment_is_installed(table, spn)) > return; > > index = SYMNAME_HASH_INDEX(spn->name); hmm... not sure if this is a little bit over the top. The idea I had was in your v3 simply replace assert(sp != spn); by if (sp == spn) { error(WARNING, "Symbol %s already installed in symname_hash\n", sp->name); continue; } That's less code plus the warning makes it easier to detect that there is a problem (for me the case sp == spn is a sign for a bug in crash). What do you think? Thanks Philipp -- Crash-utility mailing list [email protected] https://listman.redhat.com/mailman/listinfo/crash-utility
