From 00e8f7153bcdecc5c31e307c7c17fecf42308fc4 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Sat, 3 Sep 2022 00:37:06 -0700 Subject: [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. Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20220903073706.3193746-1-keescook@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 f3d601574730..f72bf0f6ccf7 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 @@ -279,27 +248,23 @@ 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" \ _ASM_ALIGN "\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" @@ -451,20 +416,19 @@ 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; \ @@ -473,45 +437,44 @@ 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__)