From 2d02fc0e933a7d4a30e8bb7c665d898d00ac5e00 Mon Sep 17 00:00:00 2001
From: Igor Mammedov <imammedo@redhat.com>
Date: Fri, 23 Nov 2018 11:58:47 +0100
Subject: [PATCH 14/34] memory: cleanup side effects of
memory_region_init_foo() on failure
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RH-Author: Igor Mammedov <imammedo@redhat.com>
Message-id: <1542974327-165907-1-git-send-email-imammedo@redhat.com>
Patchwork-id: 83127
O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH v2] memory: cleanup side effects of memory_region_init_foo() on failure
Bugzilla: 1585155
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1585155
Brew: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=19261375
if MemoryRegion intialization fails it's left in semi-initialized state,
where it's size is not 0 and attached as child to owner object.
And this leds to crash in following use-case:
(monitor) object_add memory-backend-file,id=mem1,size=99999G,mem-path=/tmp/foo,discard-data=yes
memory.c:2083: memory_region_get_ram_ptr: Assertion `mr->ram_block' failed
Aborted (core dumped)
it happens due to assumption that memory region is intialized when
memory_region_size() != 0
and therefore it's ok to access it in
file_backend_unparent()
if (memory_region_size() != 0)
memory_region_get_ram_ptr()
which happens when object_add fails and unparents failed backend making
file_backend_unparent() access invalid memory region.
Fix it by making sure that memory_region_init_foo() APIs cleanup externally
visible side effects on failure (like set size to 0 and unparenting object)
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1536064777-42312-1-git-send-email-imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 1cd3d492624da399d66c4c3e6a5eabb8f96bb0a2)
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v2:
- clean backport since dependency has been backported and merged as
(commit 754dd8f2 memory, exec: switch file ram allocation functions to 'flags' parameters)
enter the commit message for your changes. Lines starting
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
memory.c | 48 ++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 42 insertions(+), 6 deletions(-)
diff --git a/memory.c b/memory.c
index 7b47f53..4974f97 100644
--- a/memory.c
+++ b/memory.c
@@ -1519,12 +1519,18 @@ void memory_region_init_ram_shared_nomigrate(MemoryRegion *mr,
bool share,
Error **errp)
{
+ Error *err = NULL;
memory_region_init(mr, owner, name, size);
mr->ram = true;
mr->terminates = true;
mr->destructor = memory_region_destructor_ram;
- mr->ram_block = qemu_ram_alloc(size, share, mr, errp);
+ mr->ram_block = qemu_ram_alloc(size, share, mr, &err);
mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
+ if (err) {
+ mr->size = int128_zero();
+ object_unparent(OBJECT(mr));
+ error_propagate(errp, err);
+ }
}
void memory_region_init_resizeable_ram(MemoryRegion *mr,
@@ -1537,13 +1543,19 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr,
void *host),
Error **errp)
{
+ Error *err = NULL;
memory_region_init(mr, owner, name, size);
mr->ram = true;
mr->terminates = true;
mr->destructor = memory_region_destructor_ram;
mr->ram_block = qemu_ram_alloc_resizeable(size, max_size, resized,
- mr, errp);
+ mr, &err);
mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
+ if (err) {
+ mr->size = int128_zero();
+ object_unparent(OBJECT(mr));
+ error_propagate(errp, err);
+ }
}
#ifdef __linux__
@@ -1556,13 +1568,19 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
const char *path,
Error **errp)
{
+ Error *err = NULL;
memory_region_init(mr, owner, name, size);
mr->ram = true;
mr->terminates = true;
mr->destructor = memory_region_destructor_ram;
mr->align = align;
- mr->ram_block = qemu_ram_alloc_from_file(size, mr, ram_flags, path, errp);
+ mr->ram_block = qemu_ram_alloc_from_file(size, mr, ram_flags, path, &err);
mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
+ if (err) {
+ mr->size = int128_zero();
+ object_unparent(OBJECT(mr));
+ error_propagate(errp, err);
+ }
}
void memory_region_init_ram_from_fd(MemoryRegion *mr,
@@ -1573,14 +1591,20 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
int fd,
Error **errp)
{
+ Error *err = NULL;
memory_region_init(mr, owner, name, size);
mr->ram = true;
mr->terminates = true;
mr->destructor = memory_region_destructor_ram;
mr->ram_block = qemu_ram_alloc_from_fd(size, mr,
share ? RAM_SHARED : 0,
- fd, errp);
+ fd, &err);
mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
+ if (err) {
+ mr->size = int128_zero();
+ object_unparent(OBJECT(mr));
+ error_propagate(errp, err);
+ }
}
#endif
@@ -1631,13 +1655,19 @@ void memory_region_init_rom_nomigrate(MemoryRegion *mr,
uint64_t size,
Error **errp)
{
+ Error *err = NULL;
memory_region_init(mr, owner, name, size);
mr->ram = true;
mr->readonly = true;
mr->terminates = true;
mr->destructor = memory_region_destructor_ram;
- mr->ram_block = qemu_ram_alloc(size, false, mr, errp);
+ mr->ram_block = qemu_ram_alloc(size, false, mr, &err);
mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
+ if (err) {
+ mr->size = int128_zero();
+ object_unparent(OBJECT(mr));
+ error_propagate(errp, err);
+ }
}
void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
@@ -1648,6 +1678,7 @@ void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
uint64_t size,
Error **errp)
{
+ Error *err = NULL;
assert(ops);
memory_region_init(mr, owner, name, size);
mr->ops = ops;
@@ -1655,7 +1686,12 @@ void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
mr->terminates = true;
mr->rom_device = true;
mr->destructor = memory_region_destructor_ram;
- mr->ram_block = qemu_ram_alloc(size, false, mr, errp);
+ mr->ram_block = qemu_ram_alloc(size, false, mr, &err);
+ if (err) {
+ mr->size = int128_zero();
+ object_unparent(OBJECT(mr));
+ error_propagate(errp, err);
+ }
}
void memory_region_init_iommu(void *_iommu_mr,
--
1.8.3.1