1238611 - mach run --debug on Android 6.0 yields: "gdbserver" output: error: only position independent executables (PIE) are supported.

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: JimDB, defect)

Description

[Geoff Brown [:gbrown]]

I can run an Android 6.0 arm emulator, install and run Firefox on it without trouble, but I cannot run JimDB:

$ ./mach run --debug
 0:03.46 /home/gbrown/.mozbuild/android-device/jimdb-arm/bin/gdb -q --args 

Fennec GDB utilities
  (see utils/gdbinit and utils/gdbinit.local on how to configure settings)
1. Debug Fennec (default)
2. Debug Fennec with env vars and args
3. Debug using jdb
4. Debug content Mochitest
5. Debug compiled-code unit test
6. Debug Fennec with pid
Enter option from above: 1

New ADB device is "emulator-5554"
Using device emulator-5554
Using object directory: /home/gbrown/objdirs/droid
Set sysroot to "/home/gbrown/.mozbuild/android-device/jimdb-arm/lib/emulator-5554".
Updated solib-search-path.
Ignoring BHM signal.
Using package org.mozilla.fennec_gbrown.
Launching org.mozilla.fennec_gbrown... Done
Attaching to pid 1119... as non-root... in pkg dir... as root... in pkg dir... using intent... 
"gdbserver" output:
 error: only position independent executables (PIE) are supported.
"run-as" output:
 run-as: exec failed for /data/local/tmp/gdbserver: Permission denied
"run-as pkg" output:
 error: only position independent executables (PIE) are supported.
"su -c" output:
 su: invalid uid/gid '-c'
"su -c pkg" output:
 su: invalid uid/gid '-c'
"am start" output:
 --------- beginning of main
/home/gbrown/.mozbuild/android-device/jimdb-arm/bin/../utils/gdbinit:141: Error in sourced command file:
failed to run gdbserver
: No such file or directory.
(gdb) 

I assume the same problem exists on any Lollipop+ device.

I guess we need a PIE build of gdbserver.

Comment 1

[Nick Alexander :nalexander [he/him]]

nchen: sounds like you would know what to do here.

Comment 2

[(inactive) Jim Chen [:jchen] [:darchons]]

snorp has a fix.

Comment 3

[James Willcox (:snorp) ([e-mail]) (he/him)]

I assume Jim is referring to using the gdbserver that comes with the NDK. I need to work on it some more. In the mean time, you can use the updated gdbserver package in your jimdb from here: https://people.mozilla.org/~nchen/jimdb/gdbserver-arm.tar.bz2

Comment 4

[Geoff Brown [:gbrown]]

(In reply to James Willcox (:snorp) ([e-mail]) from comment #3)
> In the mean time, you can use the updated
> gdbserver package in your jimdb from here:
> https://people.mozilla.org/~nchen/jimdb/gdbserver-arm.tar.bz2

I quickly tested against 4.3 and 6.0 emulators and this worked fine for me. I'll need to update the jimdb packages on tooltool.

In the meantime, overwriting ~/.mozbuild/android-device/jimdb-arm/bin/gdbserver with the version in https://people.mozilla.org/~nchen/jimdb/gdbserver-arm.tar.bz2 should allow running via 'mach run --debug'.

Comment 5

[Geoff Brown [:gbrown]]

PIE doesn't work on Android < 4.1; I'll need to take that into account too.

http://stackoverflow.com/questions/30498776/position-independent-executables-and-android-lollipop

Comment 6

[Geoff Brown [:gbrown]]

Attachment: use pie versions of gdbserver when sdk level >= 21

On newer Androids (sdk level >= 21), native executables must be in PIE format. On these devices, the gdbserver included in our jimdb archives cannot be used.  Unfortunately, PIE executables will not work on older Androids: We need to support both, and make a selection based on Android version.

This patch updates the 'mach run --debug' command support to detect sdk level >= 21 and then use different tooltool archives containing PIE executables.

There were 6 jimdb archive varieties:
 - linux 32 - arm
 - linux 32 - x86
 - linux 64 - arm
 - linux 64 - x86
 - macosx - arm
 - macosx - x86

This patch adds support for 3 more:
 - linux 32 - arm - pie
 - linux 64 - arm - pie
 - macosx - arm - pie

We still need:
 - linux 32 - x86 - pie
 - linux 64 - x86 - pie
 - macosx - x86 - pie

but I cannot find an x86 PIE format gdbserver anywhere. I intend to leave this bug open and add x86 PIE support when it becomes available.

Comment 7

[Joel Maher ( :jmaher ) (UTC -8)]

Comment on attachment 8711215 [details] [diff] [review]
use pie versions of gdbserver when sdk level >= 21

Review of attachment 8711215 [details] [diff] [review]:
-----------------------------------------------------------------

I would like the error handling to be better, otherwise this looks good.

::: testing/mozbase/mozrunner/mozrunner/devices/android_device.py
@@ +704,5 @@
> +        cmd = ['getprop', 'ro.build.version.sdk']
> +        _log_debug(cmd)
> +        output = dm.shellCheckOutput(cmd, timeout=10)
> +        if output:
> +            sdk_level = int(output)

if we get an exception here we return x86 from this- that doesn't seem right.

Comment 8

[Geoff Brown [:gbrown]]

I should guard against ValueError and perhaps other exceptions - I'll update on landing. If the Android version cannot be determined, I think the best I can do here is warn and guess.

Comment 9

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/5edf01b87f78

Comment 10

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/5edf01b87f78

Comment 11

[Samael Wang [:freesamael] (away for now)]

(In reply to Geoff Brown [:gbrown] from comment #6) 
> but I cannot find an x86 PIE format gdbserver anywhere. I intend to leave
> this bug open and add x86 PIE support when it becomes available.

I'm new to Fennec and just encountered the same issue. It seems the prebuilt gdbserver from AOSP [1] works to me on a Android M x86 emulator. Is that what you're looking for?

[1] https://android.googlesource.com/platform/prebuilts/misc/+/android-6.0.0_r26/android-x86/gdbserver

Comment 12

[Geoff Brown [:gbrown]]

(In reply to Samael Wang [:freesamael][:sawang] from comment #11)
> Is that what you're looking for?

Yes! Thank you very much!

I'll use that to complete this bug.

Comment 13

[Geoff Brown [:gbrown]]

Attachment: update jimdb tooltool manifests for x86-pie

This adds 3 new tooltool manifests for x86-pie jimdb archives on linux-32/linux-64/macosx-64, completing PIE support for JimDB. Each of the archives is derived from the corresponding non-PIE archive, patched with the new version of gdbserver that works on Android 6.0. The patch also removes the earlier warning for x86 + PIE and allows for the x86-pie platforms.

jmaher -- This will be a pain to verify unless you have an x86 build of Fennec and an Android 6.0 x86 device to test on. I'd be happy with a visual review of the manifests and your rubber-stamp. (I verified on Linux 64 with the Android 6 x86 emulator.)

Comment 14

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/37a288bd1476

Comment 15

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/37a288bd1476