------- Comment #9 from guested dot portrayed dot stephen at blacksapphire dot
com 2007-08-08 05:15 -------
Created an attachment (id=14042)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14042&action=view)
This fixes a very similar bug in 4.1.1
gcc version 4.1.1 contains a very similar (but not quite the same) bug where
function epilogues like this are generated for ARM thumb targets.
empty:
push {r7, lr}
add r7, sp, #8
mov sp, r7
sub sp, sp, #8
@ sp needed for prologue
pop {r7}
pop {r0}
bx r0
The problem is that between "mov sp, r7" and "sub sp, #8", the stack pointer
points above the valid stack bottom, and if an interrupt occurs between these
points, stack contents get overwritten.
To generate the above code, use this test.c file:
--- test.c
void empty(void);
void empty()
{
}
--- end test.c
Use this command:
/opt/arm-none-eabi/bin/arm-none-eabi-gcc -S -o test.s test.c -mthumb
-fno-omit-frame-pointer -O2
The attached patch fixes this bug.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11222
