linux/tools/testing
Mathieu Desnoyers fe22983d92 rseq/selftests: x86: Work-around bogus gcc-8 optimisation
gcc-8 version 8.1.0, 8.2.0, and 8.3.0 generate broken assembler with asm
goto that have a thread-local storage "m" input operand on both x86-32
and x86-64. For instance:

__thread int var;

static int fct(void)
{
        asm goto (      "jmp %l[testlabel]\n\t"
                        : : [var] "m" (var) : : testlabel);
        return 0;
testlabel:
        return 1;
}

int main()
{
        return fct();
}

% gcc-8 -O2 -o test-asm-goto test-asm-goto.c
/tmp/ccAdHJbe.o: In function `main':
test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2'
collect2: error: ld returned 1 exit status

% gcc-8 -m32 -O2 -o test-asm-goto test-asm-goto.c
/tmp/ccREsVXA.o: In function `main':
test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2'
collect2: error: ld returned 1 exit status

Work-around this compiler bug in the rseq-x86.h header by passing the
address of the __rseq_abi TLS as a register operand rather than using
the "m" input operand.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90193
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: linux-kselftest@vger.kernel.org
CC: "H . Peter Anvin" <hpa@zytor.com>
CC: Chris Lameter <cl@linux.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
CC: Paul Turner <pjt@google.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ben Maurer <bmaurer@fb.com>
CC: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:30:14 -06:00
..
fault-injection License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ktest These commits have either been sitting in my INBOX or have been 2018-04-11 16:42:27 -07:00
nvdimm device-dax for 5.1 2019-03-16 13:05:32 -07:00
radix-tree radix tree: Don't return retry entries from lookup 2018-12-06 08:26:16 -05:00
scatterlist tools/testing/scatterlist: Test new __sg_alloc_table_from_pages 2017-09-07 10:54:40 +01:00
selftests rseq/selftests: x86: Work-around bogus gcc-8 optimisation 2019-05-07 15:30:14 -06:00
vsock VSOCK: add tools/testing/vsock/vsock_diag_test 2017-10-05 18:44:17 -07:00