Tony, Luck, Tony wrote:
I've just realized that this patch probably should also be applied for the ia64 arch - but I cannot test it due to lack of hardware.Markus, Sorry for not picking this up sooner. Do you have a simple test program that I can run (I do have the hardware :-)
I've attached the test program I had originally sent to LKML to demonstrate the problem. The correct i386 output would be some alignment like this (and I expect that currently the sighandler is mis-aligned on IA64):
in main : sp = 0xff9d0140 in test : sp = 0xff9d0130 in sighandler: sp = 0xff9cfe30 All done. ~Markus
-Tony
-- Markus Oberhumer, <markus@xxxxxxxxxxxxx>, http://www.oberhumer.com/
/* test signal stack alignment (sigframe)
*
* a small user-space demo program to show that the signal stack
* is currently mis-aligned on i386-linux
*
* Markus F.X.J. Oberhumer <markus@xxxxxxxxxxxxx>
*/
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
void sighandler(int);
void test(void);
volatile unsigned long sp = 0;
/* assembler prologue code that stores the stack pointer into 'sp'
* and then jumps to the real function */
#if defined(__i386__)
asm(
".text\n"
"sighandler:\n"
"lea 4(%esp), %eax\n"
"mov %eax, (sp)\n"
"jmp do_sighandler\n"
"test:\n"
"lea 4(%esp), %eax\n"
"mov %eax, (sp)\n"
"jmp do_test\n"
".globl main\n"
"main:\n"
"lea 4(%esp), %eax\n"
"mov %eax, (sp)\n"
"jmp do_main\n"
);
#elif defined(__x86_64__)
asm(
".text\n"
"sighandler:\n"
"lea 8(%rsp), %rax\n"
"mov %rax, sp(%rip)\n"
"jmp do_sighandler\n"
"test:\n"
"lea 8(%rsp), %rax\n"
"mov %rax, sp(%rip)\n"
"jmp do_test\n"
".globl main\n"
"main:\n"
"lea 8(%rsp), %rax\n"
"mov %rax, sp(%rip)\n"
"jmp do_main\n"
);
#else
#error "arch not supported - please insert your code here"
#endif
void do_sighandler(void)
{
printf("in sighandler: sp = 0x%lx\n", sp);
}
void do_test(void)
{
printf("in test : sp = 0x%lx\n", sp);
signal(SIGUSR1, sighandler);
raise(SIGUSR1);
}
int do_main(void)
{
printf("in main : sp = 0x%lx\n", sp);
test();
printf("All done.\n");
return 0;
}
/* vim:set ts=4 et: */
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