From 80c13595d0d3b8a49fe41e9538381f744ec7e6ed Mon Sep 17 00:00:00 2001 From: Guillem Jover Date: Wed, 14 Aug 2019 02:24:39 +0200 Subject: [PATCH libaio] harness: Fix PROT_WRITE mmap check This partially reverts commit d7f5065448efb49b2a26e728ff735e12ea05b62e. The actual problem in the original code was that read() was being used to assert whether the buffer was readable, but the kernel was instead reading from the file descriptor and then writing into the buffer, so no EFAULT was being generated (on architectures that do so). We needed to use a write() so that the kernel would read from the buffer. Signed-off-by: Guillem Jover --- harness/cases/5.t | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/harness/cases/5.t b/harness/cases/5.t index 7d67562..b0a7c56 100644 --- a/harness/cases/5.t +++ b/harness/cases/5.t @@ -41,13 +41,12 @@ int test_main(void) assert(buf != (char *)-1); /* Whether PROT_WRITE is readable is arch-dependent. So compare - * against read result. */ - res = read(rwfd, buf, SIZE); + * against write() result (to make the kernel read from buf). */ + res = write(rwfd, buf, SIZE); if (res < 0) res = -errno; - status |= attempt_rw(rwfd, buf, SIZE, 0, READ, res); - - status |= attempt_rw(rwfd, buf, SIZE, 0, WRITE, SIZE); + status |= attempt_rw(rwfd, buf, SIZE, 0, READ, SIZE); + status |= attempt_rw(rwfd, buf, SIZE, 0, WRITE, res); return status; } -- 2.23.0.rc1.170.gbd704faa3e