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[Qemu-devel] [PULL 3/8] i386: Change X86CPUDefinition::model_id to const
From: |
Eduardo Habkost |
Subject: |
[Qemu-devel] [PULL 3/8] i386: Change X86CPUDefinition::model_id to const char* |
Date: |
Thu, 18 Jan 2018 00:01:52 -0200 |
It is valid to have a 48-character model ID on CPUID, however the
definition of X86CPUDefinition::model_id is char[48], which can
make the compiler drop the null terminator from the string.
If a CPU model happens to have 48 bytes on model_id, "-cpu help"
will print garbage and the object_property_set_str() call at
x86_cpu_load_def() will read data outside the model_id array.
We could increase the array size to 49, but this would mean the
compiler would not issue a warning if a 49-char string is used by
mistake for model_id.
To make things simpler, simply change model_id to be const char*,
and validate the string length using an assert() on
x86_register_cpudef_type().
Reported-by: "Dr. David Alan Gilbert" <address@hidden>
Signed-off-by: Eduardo Habkost <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Eduardo Habkost <address@hidden>
---
target/i386/cpu.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 4385853646..0e26fa4ea7 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -754,7 +754,7 @@ struct X86CPUDefinition {
int model;
int stepping;
FeatureWordArray features;
- char model_id[48];
+ const char *model_id;
};
static X86CPUDefinition builtin_x86_defs[] = {
@@ -923,6 +923,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
.features[FEAT_1_EDX] =
I486_FEATURES,
.xlevel = 0,
+ .model_id = "",
},
{
.name = "pentium",
@@ -934,6 +935,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
.features[FEAT_1_EDX] =
PENTIUM_FEATURES,
.xlevel = 0,
+ .model_id = "",
},
{
.name = "pentium2",
@@ -945,6 +947,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
.features[FEAT_1_EDX] =
PENTIUM2_FEATURES,
.xlevel = 0,
+ .model_id = "",
},
{
.name = "pentium3",
@@ -956,6 +959,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
.features[FEAT_1_EDX] =
PENTIUM3_FEATURES,
.xlevel = 0,
+ .model_id = "",
},
{
.name = "athlon",
@@ -2736,6 +2740,9 @@ static void x86_register_cpudef_type(X86CPUDefinition
*def)
* they shouldn't be set on the CPU model table.
*/
assert(!(def->features[FEAT_8000_0001_EDX] & CPUID_EXT2_AMD_ALIASES));
+ /* catch mistakes instead of silently truncating model_id when too long */
+ assert(def->model_id && strlen(def->model_id) <= 48);
+
type_register(&ti);
g_free(typename);
--
2.14.3
- [Qemu-devel] [PULL 0/8] x86 queue, 2018-01-17, Eduardo Habkost, 2018/01/17
- [Qemu-devel] [PULL 1/8] pc: add 2.12 machine types, Eduardo Habkost, 2018/01/17
- [Qemu-devel] [PULL 2/8] target/i386: add clflushopt to "Skylake-Server" cpu model, Eduardo Habkost, 2018/01/17
- [Qemu-devel] [PULL 3/8] i386: Change X86CPUDefinition::model_id to const char*,
Eduardo Habkost <=
- [Qemu-devel] [PULL 4/8] i386: Add support for SPEC_CTRL MSR, Eduardo Habkost, 2018/01/17
- [Qemu-devel] [PULL 5/8] i386: Add spec-ctrl CPUID bit, Eduardo Habkost, 2018/01/17
- [Qemu-devel] [PULL 8/8] i386: Add EPYC-IBPB CPU model, Eduardo Habkost, 2018/01/17
- [Qemu-devel] [PULL 6/8] i386: Add FEAT_8000_0008_EBX CPUID feature word, Eduardo Habkost, 2018/01/17
- [Qemu-devel] [PULL 7/8] i386: Add new -IBRS versions of Intel CPU models, Eduardo Habkost, 2018/01/17
- Re: [Qemu-devel] [PULL 0/8] x86 queue, 2018-01-17, Peter Maydell, 2018/01/18