Kees Cook
2022-Sep-03 07:37 UTC
[PATCH] x86/paravirt: Remove clobber bitmask from .parainstructions
The u16 "clobber" value is not used in .parainstructions since commit
27876f3882fd ("x86/paravirt: Remove clobbers from struct
paravirt_patch_site")
Remove the u16 from the section macro, the argument from all macros, and
all now-unused CLBR_* macros.
Cc: Juergen Gross <jgross at suse.com>
Cc: "Srivatsa S. Bhat (VMware)" <srivatsa at csail.mit.edu>
Cc: Alexey Makhalov <amakhalov at vmware.com>
Cc: VMware PV-Drivers Reviewers <pv-drivers at vmware.com>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Ingo Molnar <mingo at redhat.com>
Cc: Borislav Petkov <bp at alien8.de>
Cc: Dave Hansen <dave.hansen at linux.intel.com>
Cc: x86 at kernel.org
Cc: "H. Peter Anvin" <hpa at zytor.com>
Cc: Bill Wendling <morbo at google.com>
Cc: virtualization at lists.linux-foundation.org
Signed-off-by: Kees Cook <keescook at chromium.org>
---
arch/x86/include/asm/paravirt_types.h | 61 ++++++---------------------
1 file changed, 12 insertions(+), 49 deletions(-)
diff --git a/arch/x86/include/asm/paravirt_types.h
b/arch/x86/include/asm/paravirt_types.h
index 89df6c6617f5..7869c9e825df 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -2,37 +2,6 @@
#ifndef _ASM_X86_PARAVIRT_TYPES_H
#define _ASM_X86_PARAVIRT_TYPES_H
-/* Bitmask of what can be clobbered: usually at least eax. */
-#define CLBR_EAX (1 << 0)
-#define CLBR_ECX (1 << 1)
-#define CLBR_EDX (1 << 2)
-#define CLBR_EDI (1 << 3)
-
-#ifdef CONFIG_X86_32
-/* CLBR_ANY should match all regs platform has. For i386, that's just it */
-#define CLBR_ANY ((1 << 4) - 1)
-
-#define CLBR_ARG_REGS (CLBR_EAX | CLBR_EDX | CLBR_ECX)
-#define CLBR_RET_REG (CLBR_EAX | CLBR_EDX)
-#else
-#define CLBR_RAX CLBR_EAX
-#define CLBR_RCX CLBR_ECX
-#define CLBR_RDX CLBR_EDX
-#define CLBR_RDI CLBR_EDI
-#define CLBR_RSI (1 << 4)
-#define CLBR_R8 (1 << 5)
-#define CLBR_R9 (1 << 6)
-#define CLBR_R10 (1 << 7)
-#define CLBR_R11 (1 << 8)
-
-#define CLBR_ANY ((1 << 9) - 1)
-
-#define CLBR_ARG_REGS (CLBR_RDI | CLBR_RSI | CLBR_RDX | \
- CLBR_RCX | CLBR_R8 | CLBR_R9)
-#define CLBR_RET_REG (CLBR_RAX)
-
-#endif /* X86_64 */
-
#ifndef __ASSEMBLY__
#include <asm/desc_defs.h>
@@ -279,26 +248,22 @@ extern struct paravirt_patch_template pv_ops;
#define paravirt_type(op) \
[paravirt_typenum] "i" (PARAVIRT_PATCH(op)), \
[paravirt_opptr] "m" (pv_ops.op)
-#define paravirt_clobber(clobber) \
- [paravirt_clobber] "i" (clobber)
-
/*
* Generate some code, and mark it as patchable by the
* apply_paravirt() alternate instruction patcher.
*/
-#define _paravirt_alt(insn_string, type, clobber) \
+#define _paravirt_alt(insn_string, type) \
"771:\n\t" insn_string "\n" "772:\n" \
".pushsection .parainstructions,\"a\"\n" \
_ASM_ALIGN "\n" \
_ASM_PTR " 771b\n" \
" .byte " type "\n" \
" .byte 772b-771b\n" \
- " .short " clobber "\n" \
".popsection\n"
/* Generate patchable code, with the default asm parameters. */
#define paravirt_alt(insn_string) \
- _paravirt_alt(insn_string, "%c[paravirt_typenum]",
"%c[paravirt_clobber]")
+ _paravirt_alt(insn_string, "%c[paravirt_typenum]")
/* Simple instruction patching code. */
#define NATIVE_LABEL(a,x,b) "\n\t.globl " a #x "_" #b
"\n" a #x "_" #b ":\n\t"
@@ -441,20 +406,19 @@ int paravirt_disable_iospace(void);
})
-#define ____PVOP_CALL(ret, op, clbr, call_clbr, extra_clbr, ...) \
+#define ____PVOP_CALL(ret, op, call_clbr, extra_clbr, ...) \
({ \
PVOP_CALL_ARGS; \
PVOP_TEST_NULL(op); \
asm volatile(paravirt_alt(PARAVIRT_CALL) \
: call_clbr, ASM_CALL_CONSTRAINT \
: paravirt_type(op), \
- paravirt_clobber(clbr), \
##__VA_ARGS__ \
: "memory", "cc" extra_clbr); \
ret; \
})
-#define ____PVOP_ALT_CALL(ret, op, alt, cond, clbr, call_clbr, \
+#define ____PVOP_ALT_CALL(ret, op, alt, cond, call_clbr, \
extra_clbr, ...) \
({ \
PVOP_CALL_ARGS; \
@@ -463,45 +427,44 @@ int paravirt_disable_iospace(void);
alt, cond) \
: call_clbr, ASM_CALL_CONSTRAINT \
: paravirt_type(op), \
- paravirt_clobber(clbr), \
##__VA_ARGS__ \
: "memory", "cc" extra_clbr); \
ret; \
})
#define __PVOP_CALL(rettype, op, ...) \
- ____PVOP_CALL(PVOP_RETVAL(rettype), op, CLBR_ANY, \
+ ____PVOP_CALL(PVOP_RETVAL(rettype), op, \
PVOP_CALL_CLOBBERS, EXTRA_CLOBBERS, ##__VA_ARGS__)
#define __PVOP_ALT_CALL(rettype, op, alt, cond, ...) \
- ____PVOP_ALT_CALL(PVOP_RETVAL(rettype), op, alt, cond, CLBR_ANY,\
+ ____PVOP_ALT_CALL(PVOP_RETVAL(rettype), op, alt, cond, \
PVOP_CALL_CLOBBERS, EXTRA_CLOBBERS, \
##__VA_ARGS__)
#define __PVOP_CALLEESAVE(rettype, op, ...) \
- ____PVOP_CALL(PVOP_RETVAL(rettype), op.func, CLBR_RET_REG, \
+ ____PVOP_CALL(PVOP_RETVAL(rettype), op.func, \
PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)
#define __PVOP_ALT_CALLEESAVE(rettype, op, alt, cond, ...) \
____PVOP_ALT_CALL(PVOP_RETVAL(rettype), op.func, alt, cond, \
- CLBR_RET_REG, PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)
+ PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)
#define __PVOP_VCALL(op, ...) \
- (void)____PVOP_CALL(, op, CLBR_ANY, PVOP_VCALL_CLOBBERS, \
+ (void)____PVOP_CALL(, op, PVOP_VCALL_CLOBBERS, \
VEXTRA_CLOBBERS, ##__VA_ARGS__)
#define __PVOP_ALT_VCALL(op, alt, cond, ...) \
- (void)____PVOP_ALT_CALL(, op, alt, cond, CLBR_ANY, \
+ (void)____PVOP_ALT_CALL(, op, alt, cond, \
PVOP_VCALL_CLOBBERS, VEXTRA_CLOBBERS, \
##__VA_ARGS__)
#define __PVOP_VCALLEESAVE(op, ...) \
- (void)____PVOP_CALL(, op.func, CLBR_RET_REG, \
+ (void)____PVOP_CALL(, op.func, \
PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)
#define __PVOP_ALT_VCALLEESAVE(op, alt, cond, ...) \
- (void)____PVOP_ALT_CALL(, op.func, alt, cond, CLBR_RET_REG, \
+ (void)____PVOP_ALT_CALL(, op.func, alt, cond, \
PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)
--
2.34.1
Juergen Gross
2022-Sep-05 08:09 UTC
[PATCH] x86/paravirt: Remove clobber bitmask from .parainstructions
On 03.09.22 09:37, Kees Cook wrote:> The u16 "clobber" value is not used in .parainstructions since commit > 27876f3882fd ("x86/paravirt: Remove clobbers from struct paravirt_patch_site") > > Remove the u16 from the section macro, the argument from all macros, and > all now-unused CLBR_* macros. > > Cc: Juergen Gross <jgross at suse.com> > Cc: "Srivatsa S. Bhat (VMware)" <srivatsa at csail.mit.edu> > Cc: Alexey Makhalov <amakhalov at vmware.com> > Cc: VMware PV-Drivers Reviewers <pv-drivers at vmware.com> > Cc: Thomas Gleixner <tglx at linutronix.de> > Cc: Ingo Molnar <mingo at redhat.com> > Cc: Borislav Petkov <bp at alien8.de> > Cc: Dave Hansen <dave.hansen at linux.intel.com> > Cc: x86 at kernel.org > Cc: "H. Peter Anvin" <hpa at zytor.com> > Cc: Bill Wendling <morbo at google.com> > Cc: virtualization at lists.linux-foundation.org > Signed-off-by: Kees Cook <keescook at chromium.org>Reviewed-by: Juergen Gross <jgross at suse.com> Juergen -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_0xB0DE9DD628BF132F.asc Type: application/pgp-keys Size: 3098 bytes Desc: OpenPGP public key URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20220905/3b416717/attachment.bin> -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature Type: application/pgp-signature Size: 495 bytes Desc: OpenPGP digital signature URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20220905/3b416717/attachment.sig>