* [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable
@ 2019-07-23 7:22 Tom de Vries
2019-07-29 9:57 ` Alan Hayward
2019-08-16 18:49 ` [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable Pedro Alves
0 siblings, 2 replies; 6+ messages in thread
From: Tom de Vries @ 2019-07-23 7:22 UTC (permalink / raw)
To: gdb-patches
Hi,
When running gdb.base/dump.exp with --target_board=unix/-fPIE/-pie, we get:
...
Running gdb/testsuite/gdb.base/dump.exp ...
FAIL: gdb.base/dump.exp: dump array as value, intel hex
...
The FAIL happens because although the test specifies nopie, the exec is
in fact compiled as PIE. The "-fPIE -pie" options specified using the
target_board are interpreted by dejagnu as multilib_flags, and end up
overriding the nopie flags.
Fix this by checking in gdb_compile if the resulting exec is PIE despite of
a nopie setting, and if so return an error:
...
Running gdb/testsuite/gdb.base/dump.exp ...
gdb compile failed, nopie failed to prevent PIE executable
=== gdb Summary ===
nr of untested testcases 1
...
Tested on x86_64-linux.
OK for trunk?
Thanks,
- Tom
[gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable
2019-07-23 Tom de Vries <tdevries@suse.de>
PR testsuite/24834
* lib/gdb.exp (gdb_compile): Fail if nopie results in PIE executable.
(exec_is_pie): New proc.
---
gdb/testsuite/lib/gdb.exp | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 49ec8b2a55..5ec0912325 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3760,6 +3760,12 @@ proc gdb_compile {source dest type options} {
regsub "\[\r\n\]*$" "$result" "" result
regsub "^\[\r\n\]*" "$result" "" result
+ if { $type == "executable" && $result == "" && $nopie != -1 } {
+ if { [exec_is_pie "$dest"] } {
+ set result "nopie failed to prevent PIE executable"
+ }
+ }
+
if {[lsearch $options quiet] < 0} {
# We shall update this on a per language basis, to avoid
# changing the entire testsuite in one go.
@@ -5160,6 +5166,18 @@ proc exec_has_index_section { executable } {
return 0
}
+# Return true if EXECUTABLE is a Position Independent Executable.
+
+proc exec_is_pie { executable } {
+ set readelf_program [gdb_find_readelf]
+ set res [catch {exec $readelf_program -d $executable \
+ | grep -E "(FLAGS_1).*Flags:.* PIE($| )" }]
+ if { $res == 0 } {
+ return 1
+ }
+ return 0
+}
+
# Return true if a test should be skipped due to lack of floating
# point support or GDB can't fetch the contents from floating point
# registers.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable
2019-07-23 7:22 [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable Tom de Vries
@ 2019-07-29 9:57 ` Alan Hayward
2019-07-30 1:20 ` Simon Marchi
2019-08-16 18:49 ` [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable Pedro Alves
1 sibling, 1 reply; 6+ messages in thread
From: Alan Hayward @ 2019-07-29 9:57 UTC (permalink / raw)
To: Tom de Vries; +Cc: gdb-patches\@sourceware.org, nd
> On 23 Jul 2019, at 08:22, Tom de Vries <tdevries@suse.de> wrote:
>
> Hi,
>
> When running gdb.base/dump.exp with --target_board=unix/-fPIE/-pie, we get:
> ...
> Running gdb/testsuite/gdb.base/dump.exp ...
> FAIL: gdb.base/dump.exp: dump array as value, intel hex
> ...
>
> The FAIL happens because although the test specifies nopie, the exec is
> in fact compiled as PIE. The "-fPIE -pie" options specified using the
> target_board are interpreted by dejagnu as multilib_flags, and end up
> overriding the nopie flags.
>
> Fix this by checking in gdb_compile if the resulting exec is PIE despite of
> a nopie setting, and if so return an error:
> ...
> Running gdb/testsuite/gdb.base/dump.exp ...
> gdb compile failed, nopie failed to prevent PIE executable
>
> === gdb Summary ===
>
> nr of untested testcases 1
> ...
>
> Tested on x86_64-linux.
>
> OK for trunk?
LGTM (but I’m not a global maintainer).
I tried this on an Ubuntu18.04 (which defaults gcc to use PIE), and everything
looks fine.
>
> Thanks,
> - Tom
>
> [gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable
>
> 2019-07-23 Tom de Vries <tdevries@suse.de>
>
> PR testsuite/24834
> * lib/gdb.exp (gdb_compile): Fail if nopie results in PIE executable.
> (exec_is_pie): New proc.
>
> ---
> gdb/testsuite/lib/gdb.exp | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
> index 49ec8b2a55..5ec0912325 100644
> --- a/gdb/testsuite/lib/gdb.exp
> +++ b/gdb/testsuite/lib/gdb.exp
> @@ -3760,6 +3760,12 @@ proc gdb_compile {source dest type options} {
> regsub "\[\r\n\]*$" "$result" "" result
> regsub "^\[\r\n\]*" "$result" "" result
>
> + if { $type == "executable" && $result == "" && $nopie != -1 } {
> + if { [exec_is_pie "$dest"] } {
> + set result "nopie failed to prevent PIE executable"
> + }
> + }
> +
As a side point, I just spotted that if a script specifies both pie and nopie, then
I think it ends up as nopie because the nopie flag gets set second.
Maybe it should error if both options are sent to gdb_compile.
Not something that needs fixing with this patch though.
> if {[lsearch $options quiet] < 0} {
> # We shall update this on a per language basis, to avoid
> # changing the entire testsuite in one go.
> @@ -5160,6 +5166,18 @@ proc exec_has_index_section { executable } {
> return 0
> }
>
> +# Return true if EXECUTABLE is a Position Independent Executable.
> +
> +proc exec_is_pie { executable } {
> + set readelf_program [gdb_find_readelf]
> + set res [catch {exec $readelf_program -d $executable \
> + | grep -E "(FLAGS_1).*Flags:.* PIE($| )" }]
> + if { $res == 0 } {
> + return 1
> + }
> + return 0
> +}
> +
> # Return true if a test should be skipped due to lack of floating
> # point support or GDB can't fetch the contents from floating point
> # registers.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable
2019-07-29 9:57 ` Alan Hayward
@ 2019-07-30 1:20 ` Simon Marchi
2019-08-05 10:57 ` [committed][gdb/testsuite] Fail in gdb_compile if pie results in non-PIE executable Tom de Vries
0 siblings, 1 reply; 6+ messages in thread
From: Simon Marchi @ 2019-07-30 1:20 UTC (permalink / raw)
To: Alan Hayward, Tom de Vries; +Cc: gdb-patches\@sourceware.org, nd
On 2019-07-29 5:57 a.m., Alan Hayward wrote:
>> OK for trunk?
>
> LGTM (but I’m not a global maintainer).
>
> I tried this on an Ubuntu18.04 (which defaults gcc to use PIE), and everything
> looks fine.
Thanks, LGTM too, please push.
Simon
^ permalink raw reply [flat|nested] 6+ messages in thread
* [committed][gdb/testsuite] Fail in gdb_compile if pie results in non-PIE executable
2019-07-30 1:20 ` Simon Marchi
@ 2019-08-05 10:57 ` Tom de Vries
0 siblings, 0 replies; 6+ messages in thread
From: Tom de Vries @ 2019-08-05 10:57 UTC (permalink / raw)
To: Simon Marchi, Alan Hayward; +Cc: gdb-patches, nd
[-- Attachment #1: Type: text/plain, Size: 505 bytes --]
[ was: Re: [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results
in PIE executable ]
On 30-07-19 03:20, Simon Marchi wrote:
> On 2019-07-29 5:57 a.m., Alan Hayward wrote:
>>> OK for trunk?
>>
>> LGTM (but I’m not a global maintainer).
>>
>> I tried this on an Ubuntu18.04 (which defaults gcc to use PIE), and everything
>> looks fine.
> Thanks, LGTM too, please push.
Hi,
this follow-up patch deals with the opposite: Fail in gdb_compile if pie
results in non-PIE executable.
Thanks,
- Tom
[-- Attachment #2: 0002-gdb-testsuite-Fail-in-gdb_compile-if-pie-results-in-non-PIE-executable.patch --]
[-- Type: text/x-patch, Size: 5154 bytes --]
[gdb/testsuite] Fail in gdb_compile if pie results in non-PIE executable
When running gdb.base/break-idempotent.exp with
--target_board=unix/-fno-PIE/-no-pie, we get:
...
nr of expected passes 140
...
The test-case is compiled once with nopie and once with pie, but in both cases
we end up with a non-PIE executable. The "-fno-PIE -no-pie" options specified
using the target_board are interpreted by dejagnu as multilib_flags, and end up
overriding the pie flags.
Fix this by checking in gdb_compile if the resulting exec is non-PIE despite of
a pie setting, and if so return an error:
...
Running gdb/testsuite/gdb.base/break-idempotent.exp ...
gdb compile failed, pie failed to generate PIE executable
=== gdb Summary ===
nr of expected passes 70
nr of untested testcases 1
...
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2019-08-05 Tom de Vries <tdevries@suse.de>
* lib/gdb.exp (version_at_least): Factor out of ...
(tcl_version_at_least): ... here.
(gdb_compile): Fail if pie results in non-PIE executable.
(readelf_version, readelf_prints_pie): New proc.
(exec_is_pie): Return -1 if unknown.
---
gdb/testsuite/lib/gdb.exp | 78 ++++++++++++++++++++++++++++++++++++++---------
1 file changed, 64 insertions(+), 14 deletions(-)
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 6d16217f3b..529b6f6030 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -1103,21 +1103,27 @@ proc gdb_test { args } {
}]
}
-# Return 1 if tcl version used is at least MAJOR.MINOR
-proc tcl_version_at_least { major minor } {
- global tcl_version
- regexp {^([0-9]+)\.([0-9]+)$} $tcl_version \
- dummy tcl_version_major tcl_version_minor
- if { $tcl_version_major > $major } {
+# Return 1 if version MAJOR.MINOR is at least AT_LEAST_MAJOR.AT_LEAST_MINOR.
+proc version_at_least { major minor at_least_major at_least_minor} {
+ if { $major > $at_least_major } {
return 1
- } elseif { $tcl_version_major == $major \
- && $tcl_version_minor >= $minor } {
+ } elseif { $major == $at_least_major \
+ && $minor >= $at_least_minor } {
return 1
} else {
return 0
}
}
+# Return 1 if tcl version used is at least MAJOR.MINOR
+proc tcl_version_at_least { major minor } {
+ global tcl_version
+ regexp {^([0-9]+)\.([0-9]+)$} $tcl_version \
+ dummy tcl_version_major tcl_version_minor
+ return [version_at_least $tcl_version_major $tcl_version_minor \
+ $major $minor]
+}
+
if { [tcl_version_at_least 8 5] == 0 } {
# lrepeat was added in tcl 8.5. Only add if missing.
proc lrepeat { n element } {
@@ -3803,9 +3809,13 @@ proc gdb_compile {source dest type options} {
regsub "\[\r\n\]*$" "$result" "" result
regsub "^\[\r\n\]*" "$result" "" result
- if { $type == "executable" && $result == "" && $nopie != -1 } {
- if { [exec_is_pie "$dest"] } {
+ if { $type == "executable" && $result == "" \
+ && ($nopie != -1 || $pie != -1) } {
+ set is_pie [exec_is_pie "$dest"]
+ if { $nopie != -1 && $is_pie == 1 } {
set result "nopie failed to prevent PIE executable"
+ } elseif { $pie != -1 && $is_pie == 0 } {
+ set result "pie failed to generate PIE executable"
}
}
@@ -5209,13 +5219,53 @@ proc exec_has_index_section { executable } {
return 0
}
-# Return true if EXECUTABLE is a Position Independent Executable.
+# Return list with major and minor version of readelf, or an empty list.
+gdb_caching_proc readelf_version {
+ set readelf_program [gdb_find_readelf]
+ set res [catch {exec $readelf_program --version} output]
+ if { $res != 0 } {
+ return [list]
+ }
+ set lines [split $output \n]
+ set line [lindex $lines 0]
+ set res [regexp {[ \t]+([0-9]+)[.]([0-9]+)[^ \t]*$} \
+ $line dummy major minor]
+ if { $res != 1 } {
+ return [list]
+ }
+ return [list $major $minor]
+}
+
+# Return 1 if readelf prints the PIE flag, 0 if is doesn't, and -1 if unknown.
+proc readelf_prints_pie { } {
+ set version [readelf_version]
+ if { [llength $version] == 0 } {
+ return -1
+ }
+ set major [lindex $version 0]
+ set minor [lindex $version 1]
+ # It would be better to construct a PIE executable and test if the PIE
+ # flag is printed by readelf, but we cannot reliably construct a PIE
+ # executable if the multilib_flags dictate otherwise
+ # (--target_board=unix/-no-pie/-fno-PIE).
+ return [version_at_least $major $minor 2 26]
+}
+
+# Return 1 if EXECUTABLE is a Position Independent Executable, 0 if it is not,
+# and -1 if unknown.
proc exec_is_pie { executable } {
+ set res [readelf_prints_pie]
+ if { $res != 1 } {
+ return -1
+ }
set readelf_program [gdb_find_readelf]
- set res [catch {exec $readelf_program -d $executable \
- | grep -E "(FLAGS_1).*Flags:.* PIE($| )" }]
- if { $res == 0 } {
+ set res [catch {exec $readelf_program -d $executable} output]
+ if { $res != 0 } {
+ return -1
+ }
+ set res [regexp -line {\(FLAGS_1\).*Flags:.* PIE($| )} $output]
+ if { $res == 1 } {
return 1
}
return 0
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable
2019-07-23 7:22 [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable Tom de Vries
2019-07-29 9:57 ` Alan Hayward
@ 2019-08-16 18:49 ` Pedro Alves
2019-08-17 7:09 ` Tom de Vries
1 sibling, 1 reply; 6+ messages in thread
From: Pedro Alves @ 2019-08-16 18:49 UTC (permalink / raw)
To: Tom de Vries, gdb-patches
On 7/23/19 8:22 AM, Tom de Vries wrote:
> When running gdb.base/dump.exp with --target_board=unix/-fPIE/-pie, we get:
> ...
> Running gdb/testsuite/gdb.base/dump.exp ...
> FAIL: gdb.base/dump.exp: dump array as value, intel hex
> ...
>
> The FAIL happens because although the test specifies nopie, the exec is
> in fact compiled as PIE. The "-fPIE -pie" options specified using the
> target_board are interpreted by dejagnu as multilib_flags, and end up
> overriding the nopie flags.
I'd think it would be better to temporarily strip out -fPIE/-pie (*)
from multilib_flags if nopie is set?
(*) - and/or the contents of gdb,pie_ldflag gdb,pie_flag.
Thanks,
Pedro Alves
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable
2019-08-16 18:49 ` [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable Pedro Alves
@ 2019-08-17 7:09 ` Tom de Vries
0 siblings, 0 replies; 6+ messages in thread
From: Tom de Vries @ 2019-08-17 7:09 UTC (permalink / raw)
To: Pedro Alves, gdb-patches; +Cc: Keith Seitz
On 16-08-19 20:48, Pedro Alves wrote:
> On 7/23/19 8:22 AM, Tom de Vries wrote:
>> When running gdb.base/dump.exp with --target_board=unix/-fPIE/-pie, we get:
>> ...
>> Running gdb/testsuite/gdb.base/dump.exp ...
>> FAIL: gdb.base/dump.exp: dump array as value, intel hex
>> ...
>>
>> The FAIL happens because although the test specifies nopie, the exec is
>> in fact compiled as PIE. The "-fPIE -pie" options specified using the
>> target_board are interpreted by dejagnu as multilib_flags, and end up
>> overriding the nopie flags.
>
> I'd think it would be better to temporarily strip out -fPIE/-pie (*)
> from multilib_flags if nopie is set?
>
> (*) - and/or the contents of gdb,pie_ldflag gdb,pie_flag.
>
I'm not sure about that.
I think the rationale you're applying here is to test as much as
possible in a single run: testing more is better.
But AFAIU, the implicit assumption about multilib flags is that a range
of multilib flags is tested (because multilib flags select different
libraries, so in order to claim complete testing you'd have to test all
libraries). In other words, taking the -m32/-m64 example, that you'd
test both with --target_board='unix/-m64' and
--target_board='unix/-m32'. So, if a test-case only works for -m32, then
forcing it to -m32 for unix/-m64 only makes sure you run the test twice
in identical fashion. In which case testing more is not better, just longer.
[ The same approach is used in gcc testing: a testcase can require a
certain effective target, and multilib flags influence whether the
effective target is available or not, and if not, the test is skipped as
unsupported. ]
Thanks,
- Tom
^ permalink raw reply [flat|nested] 6+ messages in thread
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2019-07-23 7:22 [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable Tom de Vries
2019-07-29 9:57 ` Alan Hayward
2019-07-30 1:20 ` Simon Marchi
2019-08-05 10:57 ` [committed][gdb/testsuite] Fail in gdb_compile if pie results in non-PIE executable Tom de Vries
2019-08-16 18:49 ` [PATCH][gdb/testsuite] Fail in gdb_compile if nopie results in PIE executable Pedro Alves
2019-08-17 7:09 ` Tom de Vries
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