[PATCH v2 9/9] bsd-user/mmap.c: assert that target_mprotect cannot fail

From: Warner Losh <imp@bsdimp.com>
To: qemu-devel@nongnu.org
Cc: kevans@freebsd.org, "Mikaël Urankar" <mikael.urankar@gmail.com>,
	richard.henderson@linaro.org, f4bug@amsat.org,
	"Warner Losh" <imp@bsdimp.com>
Subject: [PATCH v2 9/9] bsd-user/mmap.c: assert that target_mprotect cannot fail
Date: Tue, 21 Sep 2021 22:56:36 -0600	[thread overview]
Message-ID: <20210922045636.25206-10-imp@bsdimp.com> (raw)
In-Reply-To: <20210922045636.25206-1-imp@bsdimp.com>

Similar to the equivalent linux-user change 86abac06c14. All error
conditions that target_mprotect checks are also checked by target_mmap.
EACCESS cannot happen because we are just removing PROT_WRITE.  ENOMEM
should not happen because we are modifying a whole VMA (and we have
bigger problems anyway if it happens).

Fixes a Coverity false positive, where Coverity complains about
target_mprotect's return value being passed to tb_invalidate_phys_range.

Signed-off-by: Mikaël Urankar <mikael.urankar@gmail.com>
Signed-off-by: Warner Losh <imp@bsdimp.com>
---
 bsd-user/mmap.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index 792ff00548..4ddbd50b62 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -591,10 +591,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
                 goto fail;
             if (!(prot & PROT_WRITE)) {
                 ret = target_mprotect(start, len, prot);
-                if (ret != 0) {
-                    start = ret;
-                    goto the_end;
-                }
+                assert(ret == 0);
             }
             goto the_end;
         }
-- 
2.32.0


