From: Mark Wielaard <mjw@redhat.com>
To: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: systemtap@sourceware.org, naveen.n.rao@linux.vnet.ibm.com,
ulrich.weigand@de.ibm.com, uweigand@gcc.gnu.org,
anton@samba.org, fche@redhat.com
Subject: Re: [PATCH v4 1/3] systemtap/tapsets.cxx: Fix dwarfless probes on multiple static functions
Date: Wed, 22 Apr 2015 13:40:00 -0000 [thread overview]
Message-ID: <1429710017.1938.71.camel@bordewijk.wildebeest.org> (raw)
In-Reply-To: <1429525764-23471-1-git-send-email-hemant@linux.vnet.ibm.com>
Hi Hemant,
On Mon, 2015-04-20 at 15:59 +0530, Hemant Kumar wrote:
> With multiple static functions with same names in an ELF and in absence
> of dwarf, if we probe on one of the functions, then systemtap places
> probe only on one static function ignoring the rest. This is because the
> mapping between the symbol names and their func_info is a simple map
> which doesn't allow insertion of another symbol with the same name.
>
> This patch fixes this issue by changing this map to a multimap which
> allows duplicate entries for the same symbol name. lookup_symbol code
> will return a set of func_info * instead of a single descriptor for a
> function name.
>
> We also need to fix other areas in the code where lookup_symbol() and
> lookup_symbol_address() are being called so as to look for a set of
> func_info's and a list of Dwarf_Addr's respectively, instead of a single
> descriptor.
Looks good. I pushed this with one tiny change:
@@ -8242,6 +8242,8 @@ symbol_table::purge_syscall_stubs()
if (!addrs || addrs->empty())
return;
/* Highly unlikely that multiple symbols named "sys_ni_syscall" may exist */
+ if (addrs->size() > 1)
+ cerr << _("Multiple 'sys_ni_syscall' symbols found.");
Dwarf_Addr stub_addr = addrs->front();
Just so that if this highly unlikely scenario does occur we get a
warning something is fishy.
Thanks,
Mark
next prev parent reply other threads:[~2015-04-22 13:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-20 10:30 Hemant Kumar
2015-04-20 10:30 ` [RFC PATCH 2/3] Test " Hemant Kumar
2015-04-20 11:18 ` Hemant Kumar
2015-04-22 21:21 ` Mark Wielaard
2015-04-20 10:31 ` [PATCH v4 3/3] Fix: Priotirize symbol table lookup for ppc64le Hemant Kumar
2015-04-22 13:48 ` Mark Wielaard
2015-04-22 14:30 ` Hemant Kumar
2015-04-22 13:40 ` Mark Wielaard [this message]
2015-04-22 14:36 ` [PATCH v4 1/3] systemtap/tapsets.cxx: Fix dwarfless probes on multiple static functions Hemant Kumar
2015-04-23 14:22 ` Mark Wielaard
2015-04-24 19:33 ` Mark Wielaard
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