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From: David Hildenbrand <david@redhat.com>
To: qemu-devel@nongnu.org
Cc: "David Hildenbrand" <david@redhat.com>,
	"Peter Xu" <peterx@redhat.com>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>
Subject: [GIT PULL 04/12] softmmu/physmem: Remap with proper protection in qemu_ram_remap()
Date: Tue, 19 Sep 2023 12:30:21 +0200	[thread overview]
Message-ID: <20230919103029.235736-5-david@redhat.com> (raw)
In-Reply-To: <20230919103029.235736-1-david@redhat.com>

Let's remap with the proper protection that we can derive from
RAM_READONLY.

Message-ID: <20230906120503.359863-5-david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 softmmu/physmem.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 7e03ed7e3e..88482bd32a 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2069,6 +2069,7 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
     ram_addr_t offset;
     int flags;
     void *area, *vaddr;
+    int prot;
 
     RAMBLOCK_FOREACH(block) {
         offset = addr - block->offset;
@@ -2083,13 +2084,14 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
                 flags |= block->flags & RAM_SHARED ?
                          MAP_SHARED : MAP_PRIVATE;
                 flags |= block->flags & RAM_NORESERVE ? MAP_NORESERVE : 0;
+                prot = PROT_READ;
+                prot |= block->flags & RAM_READONLY ? 0 : PROT_WRITE;
                 if (block->fd >= 0) {
-                    area = mmap(vaddr, length, PROT_READ | PROT_WRITE,
-                                flags, block->fd, offset + block->fd_offset);
+                    area = mmap(vaddr, length, prot, flags, block->fd,
+                                offset + block->fd_offset);
                 } else {
                     flags |= MAP_ANONYMOUS;
-                    area = mmap(vaddr, length, PROT_READ | PROT_WRITE,
-                                flags, -1, 0);
+                    area = mmap(vaddr, length, prot, flags, -1, 0);
                 }
                 if (area != vaddr) {
                     error_report("Could not remap addr: "
-- 
2.41.0



  parent reply	other threads:[~2023-09-19 10:32 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-19 10:30 [GIT PULL 00/12] Host Memory Backends and Memory devices queue 2023-09-19 David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 01/12] nvdimm: Reject writing label data to ROM instead of crashing QEMU David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 02/12] softmmu/physmem: Distinguish between file access mode and mmap protection David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 03/12] backends/hostmem-file: Add "rom" property to support VM templating with R/O files David Hildenbrand
2023-09-19 10:30 ` David Hildenbrand [this message]
2023-09-19 10:30 ` [GIT PULL 05/12] softmmu/physmem: Bail out early in ram_block_discard_range() with readonly files David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 06/12] softmmu/physmem: Fail creation of new files in file_ram_open() with readonly=true David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 07/12] softmmu/physmem: Never return directories from file_ram_open() David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 08/12] docs: Don't mention "-mem-path" in multi-process.rst David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 09/12] docs: Start documenting VM templating David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 10/12] softmmu/physmem: Hint that "readonly=on, rom=off" exists when opening file R/W for private mapping fails David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 11/12] machine: Improve error message when using default RAM backend id David Hildenbrand
2023-09-19 10:30 ` [GIT PULL 12/12] memory: avoid updating ioeventfds for some address_space David Hildenbrand
2023-09-19 19:13 ` [GIT PULL 00/12] Host Memory Backends and Memory devices queue 2023-09-19 Stefan Hajnoczi

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