From: Di Chen <dichen@redhat.com>
To: Aaron Merey <amerey@redhat.com>
Cc: systemtap@sourceware.org
Subject: Re: [PATCH] PR29997: Fix the symbol aliases search failure when symbol version is missing
Date: Wed, 20 Dec 2023 10:56:38 +0800 [thread overview]
Message-ID: <CAN-Pu7QsExY_i3f+mdFZn5T3YWxiPWaqgujfzOPMR8C2mmZzNw@mail.gmail.com> (raw)
In-Reply-To: <CAJDtP-QXdtpdOxoi7_p7iF=OryE7+Wq-YBP-qChgaz8m0nti1w@mail.gmail.com>
[-- Attachment #1.1: Type: text/plain, Size: 8683 bytes --]
Hey Aaron,
I have added the wildcard handling for the PR29997.
From 0c95ce19272d6e13abf6f41c4ae29b6aa925ca20 Mon Sep 17 00:00:00 2001
From: Di Chen <dichen@redhat.com>
Date: Sun, 5 Nov 2023 11:23:50 +0800
Subject: [PATCH] PR29997: Fix the symbol aliases search failure when symbol
version is missing
After calling module_info::update_symtab, function aliases will be
populated. Then the updated symtab will be used for symbol searching.
For the _IO_new_fopen familty with the aliases:
$ eu-readelf -s /lib64/libc.so.6 | grep 0000000000077440
247: 0000000000077440 14 FUNC WEAK DEFAULT 16 fopen64@
@GLIBC_2.2.5
1014: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 fopen@
@GLIBC_2.2.5
1028: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 _IO_fopen@
@GLIBC_2.2.5
1556: 0000000000077440 14 FUNC LOCAL DEFAULT 16 _IO_fopen64
3471: 0000000000077440 14 FUNC LOCAL DEFAULT 16 __new_fopen
4765: 0000000000077440 14 FUNC LOCAL DEFAULT 16
_IO_new_fopen
5110: 0000000000077440 14 FUNC WEAK DEFAULT 16 fopen64
7198: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 fopen@
@GLIBC_2.2.5
7433: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 _IO_fopen@
@GLIBC_2.2.5
a) fopen@@GLIBC_2.2.5 exists in the updated symtab
b) fopen does not exist in the updated symtab
This PR is to add a version info padding when symbol cannot be found in
the updated symtab.
Signed-off-by: Di Chen <dichen@redhat.com>
---
dwflpp.cxx | 44 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 43 insertions(+), 1 deletion(-)
diff --git a/dwflpp.cxx b/dwflpp.cxx
index 9fccca0a9..044b0ca97 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -1055,6 +1055,15 @@ dwflpp::iterate_over_functions<void>(int
(*callback)(Dwarf_Die*, void*),
}
auto range = v->equal_range(function);
+ // version padding if the symbol is not found
+ if (range.first == range.second)
+ {
+ std::string function_with_ver = function + "@";
+ for (auto it = v->begin(); it != v->end(); ++it)
+ if (it->first.find(function_with_ver) == 0)
+ function_with_ver = it->first;
+ range = v->equal_range(function_with_ver);
+ }
if (range.first != range.second)
{
for (auto it = range.first; it != range.second; ++it)
@@ -1098,7 +1107,10 @@ dwflpp::iterate_over_functions<void>(int
(*callback)(Dwarf_Die*, void*),
if (pending_interrupts) return DWARF_CB_ABORT;
const string& func_name = it->first;
Dwarf_Die& die = it->second;
- if (function_name_matches_pattern (func_name, function))
+
+ // version padding if the pattern is not matched
+ if ((function_name_matches_pattern (func_name, function)) ||
+ (function_name_matches_pattern (func_name, function + "@*")))
{
if (sess.verbose > 4)
clog << _F("function cache %s:%s match %s vs %s",
module_name.c_str(),
@@ -1141,6 +1153,15 @@ dwflpp::iterate_single_function<void>(int
(*callback)(Dwarf_Die*, void*),
}
auto range = v->equal_range(function);
+ // version padding if the symbol is not found
+ if (range.first == range.second)
+ {
+ std::string function_with_ver = function + "@";
+ for (auto it = v->begin(); it != v->end(); ++it)
+ if (it->first.find(function_with_ver) == 0)
+ function_with_ver = it->first;
+ range = v->equal_range(function_with_ver);
+ }
if (range.first != range.second)
{
for (auto it = range.first; it != range.second; ++it)
@@ -1158,6 +1179,27 @@ dwflpp::iterate_single_function<void>(int
(*callback)(Dwarf_Die*, void*),
if (rc != DWARF_CB_OK) break;
}
}
+ else if (name_has_wildcard (function))
+ {
+ for (auto it = v->begin(); it != v->end(); ++it)
+ {
+ if (pending_interrupts) return DWARF_CB_ABORT;
+ const string& func_name = it->first;
+ Dwarf_Die& die = it->second;
+
+ // version padding if the pattern is not matched
+ if ((function_name_matches_pattern (func_name, function)) ||
+ (function_name_matches_pattern (func_name, function + "@*")))
+ {
+ if (sess.verbose > 4)
+ clog << _F("function cache %s:%s match %s vs %s",
module_name.c_str(),
+ cu_name().c_str(), func_name.c_str(),
function.c_str()) << endl;
+
+ rc = (*callback)(& die, data);
+ if (rc != DWARF_CB_OK) break;
+ }
+ }
+ }
// undo the focus_on_cu
this->cu = NULL;
--
2.41.0
On Tue, Nov 21, 2023 at 12:05 AM Aaron Merey <amerey@redhat.com> wrote:
> Hi Di,
>
> Thanks for working on this.
>
> On Sun, Nov 5, 2023 at 12:00 AM Di Chen via Systemtap
> <systemtap@sourceware.org> wrote:
> >
> > From 9273dc95658b109f048e4ec9b0fcde96e34f3419 Mon Sep 17 00:00:00 2001
> > From: Di Chen <dichen@redhat.com>
> > Date: Sun, 5 Nov 2023 11:23:50 +0800
> > Subject: [PATCH] PR29997: Fix the symbol aliases search failure when
> symbol
> > version is missing
> >
> > After calling module_info::update_symtab, function aliases will be
> > populated. Then the updated symtab will be used for symbol searching.
> >
> > For the _IO_new_fopen familty with the aliases:
> >
> > $ eu-readelf -s /lib64/libc.so.6 | grep 0000000000077440
> > 247: 0000000000077440 14 FUNC WEAK DEFAULT 16 fopen64@
> > @GLIBC_2.2.5
> > 1014: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 fopen@
> > @GLIBC_2.2.5
> > 1028: 0000000000077440 14 FUNC GLOBAL DEFAULT 16
> _IO_fopen@
> > @GLIBC_2.2.5
> > 1556: 0000000000077440 14 FUNC LOCAL DEFAULT 16
> _IO_fopen64
> > 3471: 0000000000077440 14 FUNC LOCAL DEFAULT 16
> __new_fopen
> > 4765: 0000000000077440 14 FUNC LOCAL DEFAULT 16
> > _IO_new_fopen
> > 5110: 0000000000077440 14 FUNC WEAK DEFAULT 16 fopen64
> > 7198: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 fopen@
> > @GLIBC_2.2.5
> > 7433: 0000000000077440 14 FUNC GLOBAL DEFAULT 16
> _IO_fopen@
> > @GLIBC_2.2.5
> >
> > a) fopen@@GLIBC_2.2.5 exists in the updated symtab
> > b) fopen does not exist in the updated symtab
> >
> > This PR is to add a version info padding when symbol cannot be found in
> > the updated symtab.
> >
> > Signed-off-by: Di Chen <dichen@redhat.com>
> > ---
> > dwflpp.cxx | 18 ++++++++++++++++++
> > 1 file changed, 18 insertions(+)
> >
> > diff --git a/dwflpp.cxx b/dwflpp.cxx
> > index a4f66440f..22e1479c9 100644
> > --- a/dwflpp.cxx
> > +++ b/dwflpp.cxx
> > @@ -1052,6 +1052,15 @@ dwflpp::iterate_over_functions<void>(int
> > (*callback)(Dwarf_Die*, void*),
> > }
> >
> > auto range = v->equal_range(function);
> > + // version info padding if the symbol is not found
> > + if (range.first == range.second)
> > + {
> > + std::string function_with_ver = function + "@";
> > + for (auto it = v->begin(); it != v->end(); ++it)
> > + if (it->first.find(function_with_ver) == 0)
> > + function_with_ver = it->first;
> > + range = v->equal_range(function_with_ver);
> > + }
>
> This fixes the bug for function names without wildcards. However
> the bug can still be reproduced using function names with wildcards.
> For example the following command incorrectly returns no results:
>
> $ stap -L 'process("/lib64/libc.so.6").function("fo*en")'
>
> We'll need additional '@' handling in the section of
> dwflpp::iterate_over_functions that matches wildcards.
>
> > if (range.first != range.second)
> > {
> > for (auto it = range.first; it != range.second; ++it)
> > @@ -1138,6 +1147,15 @@ dwflpp::iterate_single_function<void>(int
> > (*callback)(Dwarf_Die*, void*),
> > }
> >
> > auto range = v->equal_range(function);
> > + // version info padding if the symbol is not found
> > + if (range.first == range.second)
> > + {
> > + std::string function_with_ver = function + "@";
> > + for (auto it = v->begin(); it != v->end(); ++it)
> > + if (it->first.find(function_with_ver) == 0)
> > + function_with_ver = it->first;
> > + range = v->equal_range(function_with_ver);
> > + }
> > if (range.first != range.second)
> > {
> > for (auto it = range.first; it != range.second; ++it)
> > --
> > 2.41.0
>
> Aaron
>
>
[-- Attachment #2: 0001-PR29997-Fix-the-symbol-aliases-search-failure-when-s.patch --]
[-- Type: text/x-patch, Size: 4585 bytes --]
From 0c95ce19272d6e13abf6f41c4ae29b6aa925ca20 Mon Sep 17 00:00:00 2001
From: Di Chen <dichen@redhat.com>
Date: Sun, 5 Nov 2023 11:23:50 +0800
Subject: [PATCH] PR29997: Fix the symbol aliases search failure when symbol
version is missing
After calling module_info::update_symtab, function aliases will be
populated. Then the updated symtab will be used for symbol searching.
For the _IO_new_fopen familty with the aliases:
$ eu-readelf -s /lib64/libc.so.6 | grep 0000000000077440
247: 0000000000077440 14 FUNC WEAK DEFAULT 16 fopen64@@GLIBC_2.2.5
1014: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 fopen@@GLIBC_2.2.5
1028: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 _IO_fopen@@GLIBC_2.2.5
1556: 0000000000077440 14 FUNC LOCAL DEFAULT 16 _IO_fopen64
3471: 0000000000077440 14 FUNC LOCAL DEFAULT 16 __new_fopen
4765: 0000000000077440 14 FUNC LOCAL DEFAULT 16 _IO_new_fopen
5110: 0000000000077440 14 FUNC WEAK DEFAULT 16 fopen64
7198: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 fopen@@GLIBC_2.2.5
7433: 0000000000077440 14 FUNC GLOBAL DEFAULT 16 _IO_fopen@@GLIBC_2.2.5
a) fopen@@GLIBC_2.2.5 exists in the updated symtab
b) fopen does not exist in the updated symtab
This PR is to add a version info padding when symbol cannot be found in
the updated symtab.
Signed-off-by: Di Chen <dichen@redhat.com>
---
dwflpp.cxx | 44 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 43 insertions(+), 1 deletion(-)
diff --git a/dwflpp.cxx b/dwflpp.cxx
index 9fccca0a9..044b0ca97 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -1055,6 +1055,15 @@ dwflpp::iterate_over_functions<void>(int (*callback)(Dwarf_Die*, void*),
}
auto range = v->equal_range(function);
+ // version padding if the symbol is not found
+ if (range.first == range.second)
+ {
+ std::string function_with_ver = function + "@";
+ for (auto it = v->begin(); it != v->end(); ++it)
+ if (it->first.find(function_with_ver) == 0)
+ function_with_ver = it->first;
+ range = v->equal_range(function_with_ver);
+ }
if (range.first != range.second)
{
for (auto it = range.first; it != range.second; ++it)
@@ -1098,7 +1107,10 @@ dwflpp::iterate_over_functions<void>(int (*callback)(Dwarf_Die*, void*),
if (pending_interrupts) return DWARF_CB_ABORT;
const string& func_name = it->first;
Dwarf_Die& die = it->second;
- if (function_name_matches_pattern (func_name, function))
+
+ // version padding if the pattern is not matched
+ if ((function_name_matches_pattern (func_name, function)) ||
+ (function_name_matches_pattern (func_name, function + "@*")))
{
if (sess.verbose > 4)
clog << _F("function cache %s:%s match %s vs %s", module_name.c_str(),
@@ -1141,6 +1153,15 @@ dwflpp::iterate_single_function<void>(int (*callback)(Dwarf_Die*, void*),
}
auto range = v->equal_range(function);
+ // version padding if the symbol is not found
+ if (range.first == range.second)
+ {
+ std::string function_with_ver = function + "@";
+ for (auto it = v->begin(); it != v->end(); ++it)
+ if (it->first.find(function_with_ver) == 0)
+ function_with_ver = it->first;
+ range = v->equal_range(function_with_ver);
+ }
if (range.first != range.second)
{
for (auto it = range.first; it != range.second; ++it)
@@ -1158,6 +1179,27 @@ dwflpp::iterate_single_function<void>(int (*callback)(Dwarf_Die*, void*),
if (rc != DWARF_CB_OK) break;
}
}
+ else if (name_has_wildcard (function))
+ {
+ for (auto it = v->begin(); it != v->end(); ++it)
+ {
+ if (pending_interrupts) return DWARF_CB_ABORT;
+ const string& func_name = it->first;
+ Dwarf_Die& die = it->second;
+
+ // version padding if the pattern is not matched
+ if ((function_name_matches_pattern (func_name, function)) ||
+ (function_name_matches_pattern (func_name, function + "@*")))
+ {
+ if (sess.verbose > 4)
+ clog << _F("function cache %s:%s match %s vs %s", module_name.c_str(),
+ cu_name().c_str(), func_name.c_str(), function.c_str()) << endl;
+
+ rc = (*callback)(& die, data);
+ if (rc != DWARF_CB_OK) break;
+ }
+ }
+ }
// undo the focus_on_cu
this->cu = NULL;
--
2.41.0
next prev parent reply other threads:[~2023-12-20 2:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-05 3:59 Di Chen
2023-11-20 16:05 ` Aaron Merey
2023-12-20 2:56 ` Di Chen [this message]
2024-01-18 0:15 ` Aaron Merey
2024-01-31 2:45 ` Di Chen
2024-01-31 22:38 ` Aaron Merey
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