[Bug target/59904] New: [ARM] tls-reload-1.c fails

[Bug target/59904] New: [ARM] tls-reload-1.c fails

[christophe.lyon at st dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

            Bug ID: 59904
           Summary: [ARM] tls-reload-1.c fails
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: christophe.lyon at st dot com

Since commit 206897 (LRA fix PR rtl-optimization/59858)
I have noticed that:
gcc.dg/torture/tls/tls-reload-1.c  -Os  -pie -fPIE  execution test
gcc.dg/torture/tls/tls-reload-1.c  -Os  -pie -fpie  execution test

the compiler used to ICE, but after the LRA fix the generated code is not
functional.

I have tested with qemu-arm, target arm-none-linux-gnueabi, --with-mode=thumb
--with-cpu=cortex-a9, using RUNTESTFLAGS=-march=armv5t

gcc.log contains:
qemu: uncaught target signal 6 (Aborted) - core dumped

[Bug target/59904] [ARM] tls-reload-1.c fails

[ramana at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ramana at gcc dot gnu.org

--- Comment #1 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
So, this is failing for TLS with Thumb1, PIE and armv5t. 

Needs further investigation.

[Bug target/59904] [ARM] tls-reload-1.c fails

[tony.wang at arm dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

wangzheyu <tony.wang at arm dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tony.wang at arm dot com

--- Comment #2 from wangzheyu <tony.wang at arm dot com> ---
Hi, I'm trying to reproduce this bug on the panda board(cortex-a9). With the
same configuration, the case does meet some execution failure, but in order to
clarify what happened on earth, could you please provide your own elf?
(In reply to christophe.lyon from comment #0)
> Since commit 206897 (LRA fix PR rtl-optimization/59858)
> I have noticed that:
> gcc.dg/torture/tls/tls-reload-1.c  -Os  -pie -fPIE  execution test
> gcc.dg/torture/tls/tls-reload-1.c  -Os  -pie -fpie  execution test
> 
> the compiler used to ICE, but after the LRA fix the generated code is not
> functional.
> 
> I have tested with qemu-arm, target arm-none-linux-gnueabi,
> --with-mode=thumb --with-cpu=cortex-a9, using RUNTESTFLAGS=-march=armv5t
> 
> gcc.log contains:
> qemu: uncaught target signal 6 (Aborted) - core dumped

[Bug target/59904] [ARM] tls-reload-1.c fails

[christophe.lyon at st dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

--- Comment #3 from christophe.lyon at st dot com ---
Sorry I no longer have the elf file available.
I've just looked at the current trunk status and I have a failure at link time
for these tests:
ld: gcc_tg.o: relocation R_ARM_MOVW_ABS_NC against `a local symbol' can not be
used when making a shared object; recompile with -fPIC
gcc_tg.o: error adding symbols: Bad value
collect2: error: ld returned 1 exit status
compiler exited with status 1

Not sure if it's a problem with the binutils I use (linaro-2.24-2013.12) or a
known problem with the GCC test?

[Bug target/59904] [ARM] tls-reload-1.c fails

[tony.wang at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

--- Comment #4 from wangzheyu <tony.wang at arm dot com> ---
Hi christophe,
It's ok from my side, the link time is ok. I'm not sure if it's related to your
tool chain version, but would you please provide detailed information of your
toolchain, the cmd you run for the test case, and where you get this version
binutils?
(In reply to christophe.lyon from comment #3)
> Sorry I no longer have the elf file available.
> I've just looked at the current trunk status and I have a failure at link
> time for these tests:
> ld: gcc_tg.o: relocation R_ARM_MOVW_ABS_NC against `a local symbol' can not
> be used when making a shared object; recompile with -fPIC
> gcc_tg.o: error adding symbols: Bad value
> collect2: error: ld returned 1 exit status
> compiler exited with status 1
> 
> Not sure if it's a problem with the binutils I use (linaro-2.24-2013.12) or
> a known problem with the GCC test?

[Bug target/59904] [ARM] tls-reload-1.c fails

[christophe.lyon at st dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

--- Comment #5 from christophe.lyon at st dot com ---
Created attachment 32806
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32806&action=edit
ELF binary file

[Bug target/59904] [ARM] tls-reload-1.c fails

[tony.wang at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

--- Comment #7 from wangzheyu <tony.wang at arm dot com> ---
After a close analysis of your elf, it will fail due to bad code in first call
to function checktls23. The corresponding C code is:

 if (!y || *y++ != &tls23 || *y++ != &tls23_array[3]) return 0;

The code to get address of variable tls23 is wrongly fixed up. Here is the
assembly code with analysis embedded:

checktls23:
        push    {r4, lr}
        mov     r3, r0
        sub     r2, r0, #0
        beq     .L136
        ldr     r2, .L140 << get offset of variable tls23
        ldr     r1, [r0]
        bl      __aeabi_read_tp @ load_tp_soft  << get thread point and save it
to r0
        add     r0, r0, r2   << thread point plus offset equals address of
variable tls23
        mov     r2, #0
        cmp     r1, r0
        bne     .L136
        ldr     r4, .L140+4
        bl      __aeabi_read_tp @ load_tp_soft
        ldr     r1, [r3, #4]
        add     r0, r0, r4
        cmp     r1, r0
        bne     .L136
        add     r3, r3, #8
        mov     r2, r3
.L136:
        mov     r0, r2
        @ sp needed
        pop     {r4, pc}
.L141:
        .align  2
.L140:
        .word   .LANCHOR2(tpoff)+124  << offset of tls23 is correctly
generated. but never get correctly fixed up.
        .word   .LANCHOR3(tpoff)+12

So my advice is to use a newer version of binutils to test it again.

(In reply to christophe.lyon from comment #6)
> I have re-run the tests with trunk@210140 and older binutils (Sept 2013).
> 
> The test fails at compilation with target arm-none-linux-gnueabi, and
> CFLAGS=-Os  -pie -fpie or -Os  -pie -fPIE in the following configurations:
> --with-mode=arm --with-cpu=cortex-a9
> --with-mode=arm --with-cpu=cortex-a9 RUNTESTFLAGS=-mthumb
> --with-mode=thumb --with-cpu=cortex-a9
> --with-mode=thumb --with-cpu=cortex-a9 RUNTESTFLAGS=-marm
> 
> The test compiles OK and fails at execution with
> --with-mode=thumb --with-cpu=cortex-a9 RUNTESTFLAGS=-march=armv5t
> (this is the ELF file I have attached)
> 
> The compiles and runs OK with
> --with-mode=arm --with-cpu=cortex-a9 RUNTESTFLAGS=-march=armv5t

[Bug target/59904] [ARM] tls-reload-1.c fails

[tony.wang at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

--- Comment #9 from wangzheyu <tony.wang at arm dot com> ---
Hi, would please provide your elf file with the new binutils, so that we can
verify that whether it's the same issue as your former elf. If it is, it can be
verified as a bug because you're using the latest binutils-linaro. We will
investigate this issue further. Thanks a lot.

(In reply to christophe.lyon from comment #8)
> Using GCC trunk @210861, binutils-linaro-2.24-2014.03, I can see that
> tls-reload-1.c all PASS with:
> --target arm-none-linux-gnueabi --with-mode=arm --with-cpu=cortex-a9
> --with-fpu=neon and target_board set to -march=armv5t.
> 
> When changing to --with-mode=thumb, I can see 10 failures at execution time,
> with "-pie -fpie" and -pie -fPIE" combined with -O1, -O2, -O3
> -fomit-frame-pointer, -O3 -g, and -Os.

[Bug target/59904] [ARM] tls-reload-1.c fails

[christophe.lyon at st dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

--- Comment #10 from christophe.lyon at st dot com ---
Created attachment 32863
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32863&action=edit
ELF binary file #2

Compiled with arm-none-linux-gnueabi-gcc -O1 -pie -fpie -mthumb -march=armv5t
tls-reload-1.c -o tls-reload-1.exe

Binutils Linaro 2014.03

[Bug target/59904] [ARM] tls-reload-1.c fails

[christophe.lyon at st dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59904

--- Comment #12 from christophe.lyon at st dot com ---
Created attachment 32864
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32864&action=edit
ELF binary file #3

Compiled with -Os -g3 -pie -fpie -march=armv5t -mthumb