[Qemu-devel] [PATCH for-2.0] cpu: do not use QOM casts in ENV_GET_CPU

[Paolo Bonzini <pbonzini@redhat.com>]

QOM casts are only typesafe inasmuch as we know that the argument is
a QOM object.  If it is not, the accesses to fields in Object can
access invalid memory and thus cause a segfault.

Using a QOM cast in ENV_GET_CPU is useless and harmful.  Useless,
because the cast is applied to the result of container_of, which is
type safe.  So the QOM cast is nothing but typesafety theater.
Harmful, because ENV_GET_CPU *is* used in hot paths especially
now that, in 2.0, the movement of fields from CPU_COMMON to
CPUState was completed.

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Cc: Andreas Faerber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target-alpha/cpu-qom.h      | 2 +-
 target-arm/cpu-qom.h        | 2 +-
 target-cris/cpu-qom.h       | 2 +-
 target-i386/cpu-qom.h       | 2 +-
 target-lm32/cpu-qom.h       | 2 +-
 target-m68k/cpu-qom.h       | 2 +-
 target-microblaze/cpu-qom.h | 2 +-
 target-mips/cpu-qom.h       | 2 +-
 target-ppc/cpu-qom.h        | 2 +-
 target-s390x/cpu-qom.h      | 2 +-
 target-sh4/cpu-qom.h        | 2 +-
 target-sparc/cpu-qom.h      | 2 +-
 target-unicore32/cpu-qom.h  | 2 +-
 target-xtensa/cpu-qom.h     | 2 +-
 14 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/target-alpha/cpu-qom.h b/target-alpha/cpu-qom.h
index 198f1b1..47b3130 100644
--- a/target-alpha/cpu-qom.h
+++ b/target-alpha/cpu-qom.h
@@ -70,7 +70,7 @@ static inline AlphaCPU *alpha_env_get_cpu(CPUAlphaState *env)
     return container_of(env, AlphaCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(alpha_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)alpha_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(AlphaCPU, env)
 
diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
index 00234e1..34506b5 100644
--- a/target-arm/cpu-qom.h
+++ b/target-arm/cpu-qom.h
@@ -169,7 +169,7 @@ static inline ARMCPU *arm_env_get_cpu(CPUARMState *env)
     return container_of(env, ARMCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(arm_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)arm_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(ARMCPU, env)
 
diff --git a/target-cris/cpu-qom.h b/target-cris/cpu-qom.h
index 7559366..be7a3e4 100644
--- a/target-cris/cpu-qom.h
+++ b/target-cris/cpu-qom.h
@@ -69,7 +69,7 @@ static inline CRISCPU *cris_env_get_cpu(CPUCRISState *env)
     return container_of(env, CRISCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(cris_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)cris_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(CRISCPU, env)
 
diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
index e9b3d57..dc68188 100644
--- a/target-i386/cpu-qom.h
+++ b/target-i386/cpu-qom.h
@@ -111,7 +111,7 @@ static inline X86CPU *x86_env_get_cpu(CPUX86State *env)
     return container_of(env, X86CPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(x86_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)x86_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(X86CPU, env)
 
diff --git a/target-lm32/cpu-qom.h b/target-lm32/cpu-qom.h
index 9f15093..47b3d31 100644
--- a/target-lm32/cpu-qom.h
+++ b/target-lm32/cpu-qom.h
@@ -73,7 +73,7 @@ static inline LM32CPU *lm32_env_get_cpu(CPULM32State *env)
     return container_of(env, LM32CPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(lm32_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)lm32_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(LM32CPU, env)
 
diff --git a/target-m68k/cpu-qom.h b/target-m68k/cpu-qom.h
index 7f388ed..8410df8 100644
--- a/target-m68k/cpu-qom.h
+++ b/target-m68k/cpu-qom.h
@@ -66,7 +66,7 @@ static inline M68kCPU *m68k_env_get_cpu(CPUM68KState *env)
     return container_of(env, M68kCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(m68k_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)m68k_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(M68kCPU, env)
 
diff --git a/target-microblaze/cpu-qom.h b/target-microblaze/cpu-qom.h
index 35a12b4..0c9988a 100644
--- a/target-microblaze/cpu-qom.h
+++ b/target-microblaze/cpu-qom.h
@@ -67,7 +67,7 @@ static inline MicroBlazeCPU *mb_env_get_cpu(CPUMBState *env)
     return container_of(env, MicroBlazeCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(mb_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)mb_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(MicroBlazeCPU, env)
 
diff --git a/target-mips/cpu-qom.h b/target-mips/cpu-qom.h
index 8877f81..31ed2f2 100644
--- a/target-mips/cpu-qom.h
+++ b/target-mips/cpu-qom.h
@@ -70,7 +70,7 @@ static inline MIPSCPU *mips_env_get_cpu(CPUMIPSState *env)
     return container_of(env, MIPSCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(mips_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)mips_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(MIPSCPU, env)
 
diff --git a/target-ppc/cpu-qom.h b/target-ppc/cpu-qom.h
index 47dc8e6..75704fd 100644
--- a/target-ppc/cpu-qom.h
+++ b/target-ppc/cpu-qom.h
@@ -99,7 +99,7 @@ static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
     return container_of(env, PowerPCCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(ppc_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)ppc_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(PowerPCCPU, env)
 
diff --git a/target-s390x/cpu-qom.h b/target-s390x/cpu-qom.h
index ac0460e..0f90d0b 100644
--- a/target-s390x/cpu-qom.h
+++ b/target-s390x/cpu-qom.h
@@ -73,7 +73,7 @@ static inline S390CPU *s390_env_get_cpu(CPUS390XState *env)
     return container_of(env, S390CPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(s390_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)s390_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(S390CPU, env)
 
diff --git a/target-sh4/cpu-qom.h b/target-sh4/cpu-qom.h
index c04e786..4f44b04 100644
--- a/target-sh4/cpu-qom.h
+++ b/target-sh4/cpu-qom.h
@@ -79,7 +79,7 @@ static inline SuperHCPU *sh_env_get_cpu(CPUSH4State *env)
     return container_of(env, SuperHCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(sh_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)sh_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(SuperHCPU, env)
 
diff --git a/target-sparc/cpu-qom.h b/target-sparc/cpu-qom.h
index 8e3e0de..8e4a8b5 100644
--- a/target-sparc/cpu-qom.h
+++ b/target-sparc/cpu-qom.h
@@ -71,7 +71,7 @@ static inline SPARCCPU *sparc_env_get_cpu(CPUSPARCState *env)
     return container_of(env, SPARCCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(sparc_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)sparc_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(SPARCCPU, env)
 
diff --git a/target-unicore32/cpu-qom.h b/target-unicore32/cpu-qom.h
index f727760..a572470 100644
--- a/target-unicore32/cpu-qom.h
+++ b/target-unicore32/cpu-qom.h
@@ -56,7 +56,7 @@ static inline UniCore32CPU *uc32_env_get_cpu(CPUUniCore32State *env)
     return container_of(env, UniCore32CPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(uc32_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)uc32_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(UniCore32CPU, env)
 
diff --git a/target-xtensa/cpu-qom.h b/target-xtensa/cpu-qom.h
index c6cc2d9..b27425e 100644
--- a/target-xtensa/cpu-qom.h
+++ b/target-xtensa/cpu-qom.h
@@ -79,7 +79,7 @@ static inline XtensaCPU *xtensa_env_get_cpu(const CPUXtensaState *env)
     return container_of(env, XtensaCPU, env);
 }
 
-#define ENV_GET_CPU(e) CPU(xtensa_env_get_cpu(e))
+#define ENV_GET_CPU(e) ((CPUState *)xtensa_env_get_cpu(e))
 
 #define ENV_OFFSET offsetof(XtensaCPU, env)
 
-- 
1.8.5.3