/* Test if SSE valus are correctly propagated into and out of a signal handler and also check that the same applies for uninitialised values and their origins. */ #include <assert.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/syscall.h> #include <sys/ucontext.h> static siginfo_t si; static ucontext_t uc; /* x0 is always zero, but is visible to Valgrind as uninitialised. */ static upad128_t x0; static upad128_t d0 = {0}; static void sighandler(int sig, siginfo_t *sip, ucontext_t *ucp) { si = *sip; uc = *ucp; ucp->uc_mcontext.fpregs.fp_reg_set.fpchip_state.xmm[0] = d0; ucp->uc_mcontext.fpregs.fp_reg_set.fpchip_state.xmm[1] = x0; } int main(void) { struct sigaction sa; pid_t pid; upad128_t out[8]; upad128_t y0; struct fpchip_state *fs = &uc.uc_mcontext.fpregs.fp_reg_set.fpchip_state; /* Uninitialised, but we know px[0] is 0x0. */ upad128_t *px = malloc(sizeof(*px)); x0 = px[0]; /* Uninitialised, but we know py[0] is 0x0. */ upad128_t *py = malloc(sizeof(*py)); y0 = py[0]; sa.sa_handler = sighandler; sa.sa_flags = SA_SIGINFO; if (sigfillset(&sa.sa_mask)) { perror("sigfillset"); return 1; } if (sigaction(SIGUSR1, &sa, NULL)) { perror("sigaction"); return 1; } pid = getpid(); __asm__ __volatile__( /* Set values in the SSE registers. */ "movups %[y0], %%xmm0\n" "movups %[d0], %%xmm1\n" "movups %[d0], %%xmm2\n" "movups %[y0], %%xmm3\n" "movups %[y0], %%xmm4\n" "movups %[d0], %%xmm5\n" "movups %[d0], %%xmm6\n" "movups %[y0], %%xmm7\n" /* Trigger the signal handler. */ "syscall\n" "movups %%xmm0, 0x00 + %[out]\n" "movups %%xmm1, 0x10 + %[out]\n" "movups %%xmm2, 0x20 + %[out]\n" "movups %%xmm3, 0x30 + %[out]\n" "movups %%xmm4, 0x40 + %[out]\n" "movups %%xmm5, 0x50 + %[out]\n" "movups %%xmm6, 0x60 + %[out]\n" "movups %%xmm7, 0x70 + %[out]\n" : [out] "=m" (out[0]) : "a" (SYS_kill), "D" (pid), "S" (SIGUSR1), [y0] "m" (y0), [d0] "m" (d0) : "rdx", "cc", "memory"); printf("Values in the signal handler:\n"); printf(" xmm1=%Lf, xmm2=%Lf, xmm5=%Lf, xmm6=%Lf\n", fs->xmm[1]._q, fs->xmm[2]._q, fs->xmm[5]._q, fs->xmm[6]._q); /* Check that fs->xmm[0], fs->xmm[3], fs->xmm[4] and fs->xmm[7] contain uninitialised values (origin is py[0]). */ if (fs->xmm[0]._q || fs->xmm[3]._q || fs->xmm[4]._q || fs->xmm[7]._q) assert(0); printf("Values after the return from the signal handler:\n"); printf(" xmm0=%Lf, xmm2=%Lf, xmm5=%Lf, xmm6=%Lf\n", out[0]._q, out[2]._q, out[5]._q, out[6]._q); /* Check that out[1], out[3], out[4] and out[7] contain uninitialised values (origin is px[0]). */ if (out[1]._q || out[3]._q || out[4]._q || out[7]._q) assert(0); return 0; }