0.3.0: converge relibc to upstream 0.6.0 + Red Bear patches

tests/sigaltstack.c

@@ -0,0 +1,84 @@
+#include <assert.h>
+#include <signal.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/mman.h>
+
+#include "test_helpers.h"
+
+size_t stack_size;
+void *stack_base;
+
+volatile sig_atomic_t counter = 0;
+
+void action(int sig, siginfo_t *info, void *context_raw) {
+    assert(sig == SIGUSR2);
+
+    ucontext_t *context = context_raw;
+    assert(context->uc_stack.ss_sp == stack_base);
+    assert(context->uc_stack.ss_size == stack_size);
+
+    // TODO: Technically an implementation detail, but safe to check here.
+    assert((size_t)info >= (size_t)stack_base);
+    assert((size_t)info <= ((size_t)stack_base + stack_size));
+
+    int c = counter++;
+
+    char str[] = "SIGUSR2 handlerXX\n";
+    size_t len = strlen(str);
+    str[len - 2] = '0' + (c % 10);
+    str[len - 3] = '0' + ((c / 10) % 10);
+    write(STDOUT_FILENO, str, len);
+
+    if (c < 100) {
+        raise(SIGUSR2);
+    }
+}
+
+int main(void) {
+    int status;
+
+    stack_size = 1024 * 1024; // TODO?
+    // in glibc MINSIGSTKSZ is a sysconf(MINSIGSTKSZ) macro
+    assert(stack_size >= (size_t)MINSIGSTKSZ * 100);
+    stack_base = mmap(NULL, stack_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    ERROR_IF(mmap, stack_base, == MAP_FAILED);
+
+    stack_t old_stack;
+    stack_t stack = (stack_t) { .ss_sp = stack_base, .ss_size = stack_size, .ss_flags = 0 };
+
+    status = sigaltstack(&stack, &old_stack);
+    ERROR_IF(sigaltstack, status, == -1);
+
+    assert((old_stack.ss_flags & SS_ONSTACK) == 0);
+
+    stack_t same;
+
+    status = sigaltstack(&old_stack, &same);
+    ERROR_IF(sigaltstack, status, == -1);
+    assert(same.ss_sp == stack.ss_sp);
+    assert(same.ss_size == stack.ss_size);
+    assert((same.ss_flags & SS_ONSTACK) == 0);
+
+    status = sigaltstack(&stack, NULL);
+    ERROR_IF(sigaltstack, status, == -1);
+
+    status = sigaltstack(NULL, &same);
+    ERROR_IF(sigaltstack, status, == -1);
+    assert(same.ss_sp == stack.ss_sp);
+    assert(same.ss_size == stack.ss_size);
+    assert((same.ss_flags & SS_ONSTACK) == 0);
+
+    struct sigaction sa;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_ONSTACK | SA_SIGINFO | SA_NODEFER;
+    sa.sa_sigaction = action;
+
+    status = sigaction(SIGUSR2, &sa, NULL);
+    ERROR_IF(sigaction, status, == -1);
+
+    raise(SIGUSR2);
+
+    return 0;
+}