Re: [PATCH v3 4/4] selftest/x86/signal: Include test cases for validating sigaltstack

On Tue, Dec 22, 2020 at 05:53:12PM -0800, Chang S. Bae wrote:

+static int setup_altstack(void *start, unsigned long size) +{

• stack_t ss;
• memset(&ss, 0, sizeof(ss));
• ss.ss_size = size;
• ss.ss_sp = start;
• return sigaltstack(&ss, NULL);

+}

+static jmp_buf jmpbuf;

+static void sigsegv(int sig, siginfo_t *info, void *ctx_void) +{

• if (sigalrm_expected) {

• printf("[FAIL]\tSIGSEGV signal delivery is wrong.\n");
  

"Wrong signal delivered: SIGSEGV (expected SIGALRM)."

• nerrs++;
  

• } else {

• printf("[OK]\tSIGSEGV signal is delivered.\n");
  

s/is //

• }
• siglongjmp(jmpbuf, 1);

+}

+static void sigalrm(int sig, siginfo_t *info, void *ctx_void) +{

• if (!sigalrm_expected) {

• printf("[FAIL]\tSIGALRM sigal delivery is wrong.\n");
  

See above.

• nerrs++;
  

• } else {

• printf("[OK]\tSIGALRM signal is delivered.\n");
  

Ditto.

• }

+}

+static void test_sigaltstack(void *altstack, unsigned long size) +{

• if (setup_altstack(altstack, size))

• err(1, "sigaltstack()");
  

• sigalrm_expected = (size > at_minstack_size) ? true : false;
• sethandler(SIGSEGV, sigsegv, 0);
• sethandler(SIGALRM, sigalrm, SA_ONSTACK);
• if (sigsetjmp(jmpbuf, 1) == 0) {

if (!sigsetjmp...)

• printf("[RUN]\tTest an (%s) alternate signal stack\n",
  

"Test an alternate signal stack of %ssufficient size.\n"

•        sigalrm_expected ? "enough" : "too-small");
  

"" : "in");

• printf("\tRaise SIGALRM. %s is expected to be delivered.\n",
  

•        sigalrm_expected ? "It" : "But SIGSEGV");
  

"It" : "SIGSEGV"

Drop "But".

Ask if something's not clear.