On Mon, 2016-08-22 at 18:53 +0200, Laurent Dufour wrote:
> Ensure that kernel is throwing away the suspended transaction when
> sigreturn() is called otherwise it if fails to restore the signal
> frame's TM SPRS.
>
> Signed-off-by: Laurent Dufour <lduf...@linux.vnet.ibm.com>
Reviewed-by: Cyril Bur <cyril...@gmail.com>
> ---
> tools/testing/selftests/powerpc/tm/Makefile | 2 +-
> tools/testing/selftests/powerpc/tm/tm-sigreturn.c | 89
> +++++++++++++++++++++++
> 2 files changed, 90 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/powerpc/tm/tm-sigreturn.c
>
> diff --git a/tools/testing/selftests/powerpc/tm/Makefile
> b/tools/testing/selftests/powerpc/tm/Makefile
> index 9d301d785d9e..5e0396d79c8a 100644
> --- a/tools/testing/selftests/powerpc/tm/Makefile
> +++ b/tools/testing/selftests/powerpc/tm/Makefile
> @@ -1,5 +1,5 @@
> TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-
> signal-stack \
> - tm-vmxcopy tm-fork tm-tar tm-tmspr tm-exec tm-execed
> + tm-vmxcopy tm-fork tm-tar tm-tmspr tm-exec tm-execed tm-
> sigreturn
>
> all: $(TEST_PROGS)
>
> diff --git a/tools/testing/selftests/powerpc/tm/tm-sigreturn.c
> b/tools/testing/selftests/powerpc/tm/tm-sigreturn.c
> new file mode 100644
> index 000000000000..43fa83de23a5
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/tm/tm-sigreturn.c
> @@ -0,0 +1,89 @@
> +/*
> + * Copyright 2015, Laurent Dufour, IBM Corp.
> + * Licensed under GPLv2.
> + *
> + * Test the kernel's signal returning code to check reclaim is done
> if
> + * the sigreturn() is called while in a transaction (suspended since
> active
> + * is already dropped trough the system call path).
> + *
> + * The kernel must discard the transaction when entering sigreturn,
> + * since restoring the potential TM SPRS from the signal frame is
> requiring to
> + * not be in a transaction.
> + */
> +
> +#include <unistd.h>
> +#include <sys/types.h>
> +#include <sys/wait.h>
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <signal.h>
> +#include <string.h>
> +
> +#include "utils.h"
> +#include "tm.h"
> +
> +
> +void handler(int sig)
> +{
> + uint64_t ret;
> +
> + asm __volatile__(
> + "li 3,1 ;"
> + "tbegin. ;"
> + "beq 1f ;"
> + "li 3,0 ;"
> + "tsuspend. ;"
> + "1: ;"
> + "std%X[ret] 3, %[ret] ;"
> + : [ret]"=m"(ret)
> + :
> + : "memory", "3", "cr0");
> +
> + if (ret)
> + exit(1);
> +
> + /*
> + * We return from the signal handle while in a suspended
> transaction
> + */
> +}
> +
> +
> +int tm_sigreturn(void)
> +{
> + struct sigaction sa;
> + uint64_t ret = 0;
> +
> + memset(&sa, 0, sizeof(sa));
> + sa.sa_handler = handler;
> + sigemptyset(&sa.sa_mask);
> +
> + if (sigaction(SIGSEGV, &sa, NULL))
> + exit(1);
> +
> + asm __volatile__(
> + "tbegin. ;"
> + "beq 1f ;"
> + "li 3,0 ;"
> + "std 3,0(3) ;" /* trigger SEGV
> */
> + "li 3,1 ;"
> + "std%X[ret] 3,%[ret] ;"
> + "tend. ;"
> + "b 2f ;"
> + "1: ;"
> + "li 3,2 ;"
> + "std%X[ret] 3,%[ret] ;"
> + "2: ;"
> + : [ret]"=m"(ret)
> + :
> + : "memory", "3", "cr0");
> +
> + if (ret != 2)
> + exit(1);
> +
> + exit(0);
> +}
> +
> +int main(void)
> +{
> + return test_harness(tm_sigreturn, "tm_sigreturn");
> +}
