| Message ID | 1581958106-16668-1-git-send-email-cai@lca.pw (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] kvm/emulate: fix a -Werror=cast-function-type | expand |
On 17/02/20 17:48, Qian Cai wrote: > arch/x86/kvm/emulate.c: In function 'x86_emulate_insn': > arch/x86/kvm/emulate.c:5686:22: error: cast between incompatible > function types from 'int (*)(struct x86_emulate_ctxt *)' to 'void > (*)(struct fastop *)' [-Werror=cast-function-type] > rc = fastop(ctxt, (fastop_t)ctxt->execute); > > Fix it by using an unnamed union of a (*execute) function pointer and a > (*fastop) function pointer. > > Fixes: 3009afc6e39e ("KVM: x86: Use a typedef for fastop functions") > Suggested-by: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: Qian Cai <cai@lca.pw> > --- > > v2: use an unnamed union. > > arch/x86/include/asm/kvm_emulate.h | 13 ++++++++++++- > arch/x86/kvm/emulate.c | 36 ++++++++++++++---------------------- > 2 files changed, 26 insertions(+), 23 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h > index 03946eb3e2b9..2a8f2bd2e5cf 100644 > --- a/arch/x86/include/asm/kvm_emulate.h > +++ b/arch/x86/include/asm/kvm_emulate.h > @@ -292,6 +292,14 @@ enum x86emul_mode { > #define X86EMUL_SMM_MASK (1 << 6) > #define X86EMUL_SMM_INSIDE_NMI_MASK (1 << 7) > > +/* > + * fastop functions are declared as taking a never-defined fastop parameter, > + * so they can't be called from C directly. > + */ > +struct fastop; > + > +typedef void (*fastop_t)(struct fastop *); > + > struct x86_emulate_ctxt { > const struct x86_emulate_ops *ops; > > @@ -324,7 +332,10 @@ struct x86_emulate_ctxt { > struct operand src; > struct operand src2; > struct operand dst; > - int (*execute)(struct x86_emulate_ctxt *ctxt); > + union { > + int (*execute)(struct x86_emulate_ctxt *ctxt); > + fastop_t fop; > + }; > int (*check_perm)(struct x86_emulate_ctxt *ctxt); > /* > * The following six fields are cleared together, > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index ddbc61984227..dd19fb3539e0 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -191,25 +191,6 @@ > #define NR_FASTOP (ilog2(sizeof(ulong)) + 1) > #define FASTOP_SIZE 8 > > -/* > - * fastop functions have a special calling convention: > - * > - * dst: rax (in/out) > - * src: rdx (in/out) > - * src2: rcx (in) > - * flags: rflags (in/out) > - * ex: rsi (in:fastop pointer, out:zero if exception) > - * > - * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for > - * different operand sizes can be reached by calculation, rather than a jump > - * table (which would be bigger than the code). > - * > - * fastop functions are declared as taking a never-defined fastop parameter, > - * so they can't be called from C directly. > - */ > - > -struct fastop; > - > struct opcode { > u64 flags : 56; > u64 intercept : 8; > @@ -311,8 +292,19 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt) > #define ON64(x) > #endif > > -typedef void (*fastop_t)(struct fastop *); > - > +/* > + * fastop functions have a special calling convention: > + * > + * dst: rax (in/out) > + * src: rdx (in/out) > + * src2: rcx (in) > + * flags: rflags (in/out) > + * ex: rsi (in:fastop pointer, out:zero if exception) > + * > + * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for > + * different operand sizes can be reached by calculation, rather than a jump > + * table (which would be bigger than the code). > + */ > static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop); > > #define __FOP_FUNC(name) \ > @@ -5683,7 +5675,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) > > if (ctxt->execute) { > if (ctxt->d & Fastop) > - rc = fastop(ctxt, (fastop_t)ctxt->execute); > + rc = fastop(ctxt, ctxt->fop); > else > rc = ctxt->execute(ctxt); > if (rc != X86EMUL_CONTINUE) > Queued, thank you very much. Paolo
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 03946eb3e2b9..2a8f2bd2e5cf 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -292,6 +292,14 @@ enum x86emul_mode { #define X86EMUL_SMM_MASK (1 << 6) #define X86EMUL_SMM_INSIDE_NMI_MASK (1 << 7) +/* + * fastop functions are declared as taking a never-defined fastop parameter, + * so they can't be called from C directly. + */ +struct fastop; + +typedef void (*fastop_t)(struct fastop *); + struct x86_emulate_ctxt { const struct x86_emulate_ops *ops; @@ -324,7 +332,10 @@ struct x86_emulate_ctxt { struct operand src; struct operand src2; struct operand dst; - int (*execute)(struct x86_emulate_ctxt *ctxt); + union { + int (*execute)(struct x86_emulate_ctxt *ctxt); + fastop_t fop; + }; int (*check_perm)(struct x86_emulate_ctxt *ctxt); /* * The following six fields are cleared together, diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index ddbc61984227..dd19fb3539e0 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -191,25 +191,6 @@ #define NR_FASTOP (ilog2(sizeof(ulong)) + 1) #define FASTOP_SIZE 8 -/* - * fastop functions have a special calling convention: - * - * dst: rax (in/out) - * src: rdx (in/out) - * src2: rcx (in) - * flags: rflags (in/out) - * ex: rsi (in:fastop pointer, out:zero if exception) - * - * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for - * different operand sizes can be reached by calculation, rather than a jump - * table (which would be bigger than the code). - * - * fastop functions are declared as taking a never-defined fastop parameter, - * so they can't be called from C directly. - */ - -struct fastop; - struct opcode { u64 flags : 56; u64 intercept : 8; @@ -311,8 +292,19 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt) #define ON64(x) #endif -typedef void (*fastop_t)(struct fastop *); - +/* + * fastop functions have a special calling convention: + * + * dst: rax (in/out) + * src: rdx (in/out) + * src2: rcx (in) + * flags: rflags (in/out) + * ex: rsi (in:fastop pointer, out:zero if exception) + * + * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for + * different operand sizes can be reached by calculation, rather than a jump + * table (which would be bigger than the code). + */ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop); #define __FOP_FUNC(name) \ @@ -5683,7 +5675,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) if (ctxt->execute) { if (ctxt->d & Fastop) - rc = fastop(ctxt, (fastop_t)ctxt->execute); + rc = fastop(ctxt, ctxt->fop); else rc = ctxt->execute(ctxt); if (rc != X86EMUL_CONTINUE)
arch/x86/kvm/emulate.c: In function 'x86_emulate_insn': arch/x86/kvm/emulate.c:5686:22: error: cast between incompatible function types from 'int (*)(struct x86_emulate_ctxt *)' to 'void (*)(struct fastop *)' [-Werror=cast-function-type] rc = fastop(ctxt, (fastop_t)ctxt->execute); Fix it by using an unnamed union of a (*execute) function pointer and a (*fastop) function pointer. Fixes: 3009afc6e39e ("KVM: x86: Use a typedef for fastop functions") Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Qian Cai <cai@lca.pw> --- v2: use an unnamed union. arch/x86/include/asm/kvm_emulate.h | 13 ++++++++++++- arch/x86/kvm/emulate.c | 36 ++++++++++++++---------------------- 2 files changed, 26 insertions(+), 23 deletions(-)