[Bug target/44888] New: Stack pointer corruption within interrupt routine when compiled with -Os

[Bug target/44888] New: Stack pointer corruption within interrupt routine when compiled with -Os

[rob dot thornburrow at adder dot com]

# 1 "irq.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "irq.c"

extern void add_irq(int, void (*irq)(void));
extern void do_something(void);

static __attribute__ ((interrupt("IRQ"))) void irq(void)
{
    unsigned long ints;

    ints = (*(volatile unsigned long *)(0x00000000));
    ints &= ~(*(volatile unsigned long *)(0x00000004));

    if (ints & 0x1)
        do_something();

    (*(volatile unsigned long *)(0x00000000)) = ints;
}

void init(void)
{
    add_irq(0, irq);
}


When compiled with -Os using gcc 4.5.0 (arm-none-eabi), the generated assembly
for irq() subtracts 4 from the stack pointer immediately prior to calling
do_something() but never adds 4 back before the function exits.  This results
in the program counter (and all registers saved at the start of the function)
being loaded with incorrect values.

This doesn't happen with 4.5.0 when compiled with no optimisation (-O0) or with
4.4.2 (arm-elf) with any optimisation level.

It appears to only be a problem when the function is defined as an interrupt
handler as when defined as a normal function (with standard entry/exit
wrappers) the generated assembly looks correct.

Target: arm-none-eabi
Configured with: ../gcc-4.5.0/configure --target=arm-none-eabi
--prefix=/home/ya
garto/install --disable-nls --disable-shared --disable-threads --with-gcc
--with
-gnu-ld --with-gnu-as --with-dwarf2 --enable-languages=c,c++ --enable-interwork
--enable-multilib --with-newlib
--with-headers=../newlib-1.18.0/newlib/libc/incl
ude --disable-libssp --disable-libstdcxx-pch --disable-libmudflap
--disable-libg
omp -v
Thread model: single
gcc version 4.5.0 (GCC)
COLLECT_GCC_OPTIONS='-mcpu=arm7tdmi-s' '-std=gnu99' '-Wall' '-c' '-fno-common'
'-Os' '-o'


-- 
           Summary: Stack pointer corruption within interrupt routine when
                    compiled with -Os
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rob dot thornburrow at adder dot com
GCC target triplet: arm-none-eabi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44888

[Bug target/44888] Stack pointer corruption within interrupt routine when compiled with -Os

[ramana at gcc dot gnu dot org]

------- Comment #1 from ramana at gcc dot gnu dot org  2010-07-12 09:35 -------
Confirmed - I think it should be fixed by this patch here. 

http://gcc.gnu.org/ml/gcc-patches/2010-07/msg00495.html

Jie : do you think you could backport this to the 4.5 branch ? 

cheers
Ramana


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jiez at gcc dot gnu dot org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
      Known to fail|                            |4.5.0
      Known to work|                            |4.4.4 4.6.0
   Last reconfirmed|0000-00-00 00:00:00         |2010-07-12 09:35:45
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44888

[Bug target/44888] Stack pointer corruption within interrupt routine when compiled with -Os

[jiez at gcc dot gnu dot org]

------- Comment #2 from jiez at gcc dot gnu dot org  2010-07-12 09:57 -------
Ramana, I will do it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44888

[Bug target/44888] Stack pointer corruption within interrupt routine when compiled with -Os

[jiez at gcc dot gnu dot org]

------- Comment #3 from jiez at gcc dot gnu dot org  2010-07-12 14:06 -------
My patch has been committed on trunk and 4.5 branch. This bug should be fixed
now. Please verify.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44888

[Bug target/44888] Stack pointer corruption within interrupt routine when compiled with -Os

[jiez at gcc dot gnu dot org]

------- Comment #4 from jiez at gcc dot gnu dot org  2010-07-12 14:07 -------
The updated patch:

http://gcc.gnu.org/ml/gcc-patches/2010-07/msg00968.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44888

[Bug target/44888] Stack pointer corruption within interrupt routine when compiled with -Os

[rob dot thornburrow at adder dot com]

------- Comment #5 from rob dot thornburrow at adder dot com  2010-07-13 08:25 -------
Patch verified against 4.5.0 (manual patch of config/arm/arm.c as I'm currently
unable to get the 4.5 branch).


-- 

rob dot thornburrow at adder dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44888