Commit a26f415b authored by Michael Neuling's avatar Michael Neuling Committed by Michael Ellerman

selftests/powerpc: Add TM signal with invalid stack test

Test the kernels signal generation code to ensure it can handle an
invalid stack pointer when transactional.
Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
Tested-by: default avatarAnshuman Khandual <khandual@linux.vnet.ibm.com>
[mpe: Skip if we don't have TM]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 25007a69
tm-resched-dscr tm-resched-dscr
tm-syscall tm-syscall
tm-signal-msr-resv tm-signal-msr-resv
tm-signal-stack
TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack
all: $(TEST_PROGS) all: $(TEST_PROGS)
......
/*
* Copyright 2015, Michael Neuling, IBM Corp.
* Licensed under GPLv2.
*
* Test the kernel's signal delievery code to ensure that we don't
* trelaim twice in the kernel signal delivery code. This can happen
* if we trigger a signal when in a transaction and the stack pointer
* is bogus.
*
* This test case registers a SEGV handler, sets the stack pointer
* (r1) to NULL, starts a transaction and then generates a SEGV. The
* SEGV should be handled but we exit here as the stack pointer is
* invalid and hance we can't sigreturn. We only need to check that
* this flow doesn't crash the kernel.
*/
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include "utils.h"
#include "tm.h"
void signal_segv(int signum)
{
/* This should never actually run since stack is foobar */
exit(1);
}
int tm_signal_stack()
{
int pid;
SKIP_IF(!have_htm());
pid = fork();
if (pid < 0)
exit(1);
if (pid) { /* Parent */
/*
* It's likely the whole machine will crash here so if
* the child ever exits, we are good.
*/
wait(NULL);
return 0;
}
/*
* The flow here is:
* 1) register a signal handler (so signal delievery occurs)
* 2) make stack pointer (r1) = NULL
* 3) start transaction
* 4) cause segv
*/
if (signal(SIGSEGV, signal_segv) == SIG_ERR)
exit(1);
asm volatile("li 1, 0 ;" /* stack ptr == NULL */
"1:"
".long 0x7C00051D ;" /* tbegin */
"beq 1b ;" /* retry forever */
".long 0x7C0005DD ; ;" /* tsuspend */
"ld 2, 0(1) ;" /* trigger segv" */
: : : "memory");
/* This should never get here due to above segv */
return 1;
}
int main(void)
{
return test_harness(tm_signal_stack, "tm_signal_stack");
}
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