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From: Laurent Vivier <laurent@vivier.eu>
To: qemu-devel@nongnu.org
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Laurent Vivier" <laurent@vivier.eu>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>
Subject: [PULL 2/4] linux-user: Use "!= 0" when checking if MAP_FIXED_NOREPLACE is non-zero
Date: Thu,  5 Nov 2020 08:08:35 +0100	[thread overview]
Message-ID: <20201105070837.558332-3-laurent@vivier.eu> (raw)
In-Reply-To: <20201105070837.558332-1-laurent@vivier.eu>

From: Peter Maydell <peter.maydell@linaro.org>

In pgd_find_hole_fallback(), Coverity doesn't like the use
of "if (MAP_FIXED_NOREPLACE || ...)" because it's using a
logical operator on a constant other than 0 or 1 and its
heuristic thinks we might have intended a bitwise operator
instead.

The logic is correct (we are checking whether the host really
has a MAP_FIXED_NOREPLACE or whether we fell back to the
"#define as 0 to ignore" from osdep.h); make Coverity
happier by explicitly writing out the comparison with zero.

Fixes: Coverity CID 1431059
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201103142636.21125-1-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/elfload.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index bf8c1bd25330..cae41d504d36 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2188,7 +2188,8 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk,
                                      PROT_NONE, flags, -1, 0);
             if (mmap_start != MAP_FAILED) {
                 munmap((void *) align_start, guest_size);
-                if (MAP_FIXED_NOREPLACE || mmap_start == (void *) align_start) {
+                if (MAP_FIXED_NOREPLACE != 0 ||
+                    mmap_start == (void *) align_start) {
                     return (uintptr_t) mmap_start + offset;
                 }
             }
-- 
2.28.0



  parent reply	other threads:[~2020-11-05  7:10 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-05  7:08 [PULL 0/4] Linux user for 5.2 patches Laurent Vivier
2020-11-05  7:08 ` [PULL 1/4] linux-user/mips/cpu_loop: silence the compiler warnings Laurent Vivier
2020-11-05  7:08 ` Laurent Vivier [this message]
2020-11-05  7:08 ` [PULL 3/4] linux-user/syscall: Fix missing target_to_host_timespec64() check Laurent Vivier
2020-11-05  7:08 ` [PULL 4/4] linux-user: Check copy_from_user() return value in vma_dump_size() Laurent Vivier
2020-11-05  7:15 ` [PULL 0/4] Linux user for 5.2 patches no-reply
2020-11-06  9:40 ` Peter Maydell

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