Comment 4 for bug 1867072

With those two patches applied I can no longer reproduce the problem, thanks!

For posterity, this is how I've been reproducing the problem:

1. Build a Linux kernel with this patch applied: https://patchwork.kernel.org/patch/11435077/
2. Run this program under the kernel:

#include <stdint.h>
#include <stdio.h>
#include <signal.h>

void handler(int signo, siginfo_t *siginfo, void *context) {
  uint32_t *begin = (uint32_t *)context;
  uint32_t *end = ((uint32_t *)context) + (sizeof(ucontext_t)/4);
  for (uint32_t *i = begin; i != end; ++i) {
    printf("%08p %08x\n", i, *i);
  }
  _exit(0);
}

int main() {
  struct sigaction sa;
  sa.sa_sigaction = handler;
  sa.sa_flags = SA_SIGINFO;
  sigaction(SIGSEGV, &sa, 0);

  return *(int *)((1ULL << 56) + 0x123456);
}

I would expect this program's output to include something like the following:

0xffffd5869bd0 46415201
0xffffd5869bd4 00000010
0xffffd5869bd8 00123456
0xffffd5869bdc 01000000

But the output that I was seeing with the bad qemu looked like this:

0xffffd5869bd0 46415201
0xffffd5869bd4 00000010
0xffffd5869bd8 00123456
0xffffd5869bdc 00000000