Merge tag 'x86_entry_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 entry code updates from Dave Hansen:
 "This is entirely composed of a set of long overdue VDSO cleanups. They
  makes the VDSO build much more logical and zap quite a bit of old
  cruft.

  It also results in a coveted net-code-removal diffstat"

* tag 'x86_entry_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/vdso: Add vdso2c to .gitignore
  x86/entry/vdso32: Omit '.cfi_offset eflags' for LLVM < 16
  MAINTAINERS: Adjust vdso file entry in INTEL SGX
  x86/entry/vdso/selftest: Update location of vgetrandom-chacha.S
  x86/entry/vdso: Fix filtering of vdso compiler flags
  x86/entry/vdso: Update the object paths for "make vdso_install"
  x86/entry/vdso32: When using int $0x80, use it directly
  x86/cpufeature: Replace X86_FEATURE_SYSENTER32 with X86_FEATURE_SYSFAST32
  x86/vdso: Abstract out vdso system call internals
  x86/entry/vdso: Include GNU_PROPERTY and GNU_STACK PHDRs
  x86/entry/vdso32: Remove open-coded DWARF in sigreturn.S
  x86/entry/vdso32: Remove SYSCALL_ENTER_KERNEL macro in sigreturn.S
  x86/entry/vdso32: Don't rely on int80_landing_pad for adjusting ip
  x86/entry/vdso: Refactor the vdso build
  x86/entry/vdso: Move vdso2c to arch/x86/tools
  x86/entry/vdso: Rename vdso_image_* to vdso*_image

6 files changed, 119 insertions, 105 deletions

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index c3b53beb1300..63b0f9aa9b3e 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -84,7 +84,7 @@
 #define X86_FEATURE_PEBS		( 3*32+12) /* "pebs" Precise-Event Based Sampling */
 #define X86_FEATURE_BTS			( 3*32+13) /* "bts" Branch Trace Store */
 #define X86_FEATURE_SYSCALL32		( 3*32+14) /* syscall in IA32 userspace */
-#define X86_FEATURE_SYSENTER32		( 3*32+15) /* sysenter in IA32 userspace */
+#define X86_FEATURE_SYSFAST32		( 3*32+15) /* sysenter/syscall in IA32 userspace */
 #define X86_FEATURE_REP_GOOD		( 3*32+16) /* "rep_good" REP microcode works well */
 #define X86_FEATURE_AMD_LBR_V2		( 3*32+17) /* "amd_lbr_v2" AMD Last Branch Record Extension Version 2 */
 #define X86_FEATURE_CLEAR_CPU_BUF	( 3*32+18) /* Clear CPU buffers using VERW */
diff --git a/arch/x86/include/asm/dwarf2.h b/arch/x86/include/asm/dwarf2.h
index 302e11b15da8..09c9684d3ad6 100644
--- a/arch/x86/include/asm/dwarf2.h
+++ b/arch/x86/include/asm/dwarf2.h
@@ -20,6 +20,7 @@
 #define CFI_RESTORE_STATE	.cfi_restore_state
 #define CFI_UNDEFINED		.cfi_undefined
 #define CFI_ESCAPE		.cfi_escape
+#define CFI_SIGNAL_FRAME	.cfi_signal_frame
 
 #ifndef BUILD_VDSO
 	/*
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 6c8fdc96be7e..2ba5f166e58f 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -361,7 +361,7 @@ else if (IS_ENABLED(CONFIG_IA32_EMULATION))				\
 
 #define VDSO_ENTRY							\
 	((unsigned long)current->mm->context.vdso +			\
-	 vdso_image_32.sym___kernel_vsyscall)
+	 vdso32_image.sym___kernel_vsyscall)
 
 struct linux_binprm;
 
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index b7253ef3205a..e8afbe9faa5b 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -27,9 +27,9 @@ struct vdso_image {
 	long sym_vdso32_rt_sigreturn_landing_pad;
 };
 
-extern const struct vdso_image vdso_image_64;
-extern const struct vdso_image vdso_image_x32;
-extern const struct vdso_image vdso_image_32;
+extern const struct vdso_image vdso64_image;
+extern const struct vdso_image vdsox32_image;
+extern const struct vdso_image vdso32_image;
 
 extern int __init init_vdso_image(const struct vdso_image *image);
 
diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
index 73b2e7ee8f0f..3cf214cc4a75 100644
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -18,6 +18,7 @@
 #include <asm/msr.h>
 #include <asm/pvclock.h>
 #include <clocksource/hyperv_timer.h>
+#include <asm/vdso/sys_call.h>
 
 #define VDSO_HAS_TIME 1
 
@@ -53,130 +54,37 @@ extern struct ms_hyperv_tsc_page hvclock_page
 	__attribute__((visibility("hidden")));
 #endif
 
-#ifndef BUILD_VDSO32
-
 static __always_inline
 long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
 {
-	long ret;
-
-	asm ("syscall" : "=a" (ret), "=m" (*_ts) :
-	     "0" (__NR_clock_gettime), "D" (_clkid), "S" (_ts) :
-	     "rcx", "r11");
-
-	return ret;
+	return VDSO_SYSCALL2(clock_gettime,64,_clkid,_ts);
 }
 
 static __always_inline
 long gettimeofday_fallback(struct __kernel_old_timeval *_tv,
 			   struct timezone *_tz)
 {
-	long ret;
-
-	asm("syscall" : "=a" (ret) :
-	    "0" (__NR_gettimeofday), "D" (_tv), "S" (_tz) : "memory");
-
-	return ret;
+	return VDSO_SYSCALL2(gettimeofday,,_tv,_tz);
 }
 
 static __always_inline
 long clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
 {
-	long ret;
-
-	asm ("syscall" : "=a" (ret), "=m" (*_ts) :
-	     "0" (__NR_clock_getres), "D" (_clkid), "S" (_ts) :
-	     "rcx", "r11");
-
-	return ret;
+	return VDSO_SYSCALL2(clock_getres,_time64,_clkid,_ts);
 }
 
-#else
-
-static __always_inline
-long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
-{
-	long ret;
-
-	asm (
-		"mov %%ebx, %%edx \n"
-		"mov %[clock], %%ebx \n"
-		"call __kernel_vsyscall \n"
-		"mov %%edx, %%ebx \n"
-		: "=a" (ret), "=m" (*_ts)
-		: "0" (__NR_clock_gettime64), [clock] "g" (_clkid), "c" (_ts)
-		: "edx");
-
-	return ret;
-}
+#ifndef CONFIG_X86_64
 
 static __always_inline
 long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
 {
-	long ret;
-
-	asm (
-		"mov %%ebx, %%edx \n"
-		"mov %[clock], %%ebx \n"
-		"call __kernel_vsyscall \n"
-		"mov %%edx, %%ebx \n"
-		: "=a" (ret), "=m" (*_ts)
-		: "0" (__NR_clock_gettime), [clock] "g" (_clkid), "c" (_ts)
-		: "edx");
-
-	return ret;
-}
-
-static __always_inline
-long gettimeofday_fallback(struct __kernel_old_timeval *_tv,
-			   struct timezone *_tz)
-{
-	long ret;
-
-	asm(
-		"mov %%ebx, %%edx \n"
-		"mov %2, %%ebx \n"
-		"call __kernel_vsyscall \n"
-		"mov %%edx, %%ebx \n"
-		: "=a" (ret)
-		: "0" (__NR_gettimeofday), "g" (_tv), "c" (_tz)
-		: "memory", "edx");
-
-	return ret;
+	return VDSO_SYSCALL2(clock_gettime,,_clkid,_ts);
 }
 
 static __always_inline long
-clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
-{
-	long ret;
-
-	asm (
-		"mov %%ebx, %%edx \n"
-		"mov %[clock], %%ebx \n"
-		"call __kernel_vsyscall \n"
-		"mov %%edx, %%ebx \n"
-		: "=a" (ret), "=m" (*_ts)
-		: "0" (__NR_clock_getres_time64), [clock] "g" (_clkid), "c" (_ts)
-		: "edx");
-
-	return ret;
-}
-
-static __always_inline
-long clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
+clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
 {
-	long ret;
-
-	asm (
-		"mov %%ebx, %%edx \n"
-		"mov %[clock], %%ebx \n"
-		"call __kernel_vsyscall \n"
-		"mov %%edx, %%ebx \n"
-		: "=a" (ret), "=m" (*_ts)
-		: "0" (__NR_clock_getres), [clock] "g" (_clkid), "c" (_ts)
-		: "edx");
-
-	return ret;
+	return VDSO_SYSCALL2(clock_getres,,_clkid,_ts);
 }
 
 #endif
diff --git a/arch/x86/include/asm/vdso/sys_call.h b/arch/x86/include/asm/vdso/sys_call.h
new file mode 100644
index 000000000000..5806b1cd6aef
--- /dev/null
+++ b/arch/x86/include/asm/vdso/sys_call.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Macros for issuing an inline system call from the vDSO.
+ */
+
+#ifndef X86_ASM_VDSO_SYS_CALL_H
+#define X86_ASM_VDSO_SYS_CALL_H
+
+#include <linux/compiler.h>
+#include <asm/cpufeatures.h>
+#include <asm/alternative.h>
+
+#ifdef CONFIG_X86_64
+# define __sys_instr	"syscall"
+# define __sys_clobber	"rcx", "r11", "memory"
+# define __sys_nr(x,y)	__NR_ ## x
+# define __sys_reg1	"rdi"
+# define __sys_reg2	"rsi"
+# define __sys_reg3	"rdx"
+# define __sys_reg4	"r10"
+# define __sys_reg5	"r8"
+#else
+# define __sys_instr	ALTERNATIVE("ds;ds;ds;int $0x80",		\
+				    "call __kernel_vsyscall",		\
+				    X86_FEATURE_SYSFAST32)
+# define __sys_clobber	"memory"
+# define __sys_nr(x,y)	__NR_ ## x ## y
+# define __sys_reg1	"ebx"
+# define __sys_reg2	"ecx"
+# define __sys_reg3	"edx"
+# define __sys_reg4	"esi"
+# define __sys_reg5	"edi"
+#endif
+
+/*
+ * Example usage:
+ *
+ * result = VDSO_SYSCALL3(foo,64,x,y,z);
+ *
+ * ... calls foo(x,y,z) on 64 bits, and foo64(x,y,z) on 32 bits.
+ *
+ * VDSO_SYSCALL6() is currently missing, because it would require
+ * special handling for %ebp on 32 bits when the vdso is compiled with
+ * frame pointers enabled (the default on 32 bits.) Add it as a special
+ * case when and if it becomes necessary.
+ */
+#define _VDSO_SYSCALL(name,suf32,...)					\
+	({								\
+		long _sys_num_ret = __sys_nr(name,suf32);		\
+		asm_inline volatile(					\
+			__sys_instr					\
+			: "+a" (_sys_num_ret)				\
+			: __VA_ARGS__					\
+			: __sys_clobber);				\
+		_sys_num_ret;						\
+	})
+
+#define VDSO_SYSCALL0(name,suf32)					\
+	_VDSO_SYSCALL(name,suf32)
+#define VDSO_SYSCALL1(name,suf32,a1)					\
+	({								\
+		register long _sys_arg1 asm(__sys_reg1) = (long)(a1);	\
+		_VDSO_SYSCALL(name,suf32,				\
+			      "r" (_sys_arg1));				\
+	})
+#define VDSO_SYSCALL2(name,suf32,a1,a2)				\
+	({								\
+		register long _sys_arg1 asm(__sys_reg1) = (long)(a1);	\
+		register long _sys_arg2 asm(__sys_reg2) = (long)(a2);	\
+		_VDSO_SYSCALL(name,suf32,				\
+			      "r" (_sys_arg1), "r" (_sys_arg2));	\
+	})
+#define VDSO_SYSCALL3(name,suf32,a1,a2,a3)				\
+	({								\
+		register long _sys_arg1 asm(__sys_reg1) = (long)(a1);	\
+		register long _sys_arg2 asm(__sys_reg2) = (long)(a2);	\
+		register long _sys_arg3 asm(__sys_reg3) = (long)(a3);	\
+		_VDSO_SYSCALL(name,suf32,				\
+			      "r" (_sys_arg1), "r" (_sys_arg2),		\
+			      "r" (_sys_arg3));				\
+	})
+#define VDSO_SYSCALL4(name,suf32,a1,a2,a3,a4)				\
+	({								\
+		register long _sys_arg1 asm(__sys_reg1) = (long)(a1);	\
+		register long _sys_arg2 asm(__sys_reg2) = (long)(a2);	\
+		register long _sys_arg3 asm(__sys_reg3) = (long)(a3);	\
+		register long _sys_arg4 asm(__sys_reg4) = (long)(a4);	\
+		_VDSO_SYSCALL(name,suf32,				\
+			      "r" (_sys_arg1), "r" (_sys_arg2),		\
+			      "r" (_sys_arg3), "r" (_sys_arg4));	\
+	})
+#define VDSO_SYSCALL5(name,suf32,a1,a2,a3,a4,a5)			\
+	({								\
+		register long _sys_arg1 asm(__sys_reg1) = (long)(a1);	\
+		register long _sys_arg2 asm(__sys_reg2) = (long)(a2);	\
+		register long _sys_arg3 asm(__sys_reg3) = (long)(a3);	\
+		register long _sys_arg4 asm(__sys_reg4) = (long)(a4);	\
+		register long _sys_arg5 asm(__sys_reg5) = (long)(a5);	\
+		_VDSO_SYSCALL(name,suf32,				\
+			      "r" (_sys_arg1), "r" (_sys_arg2),		\
+			      "r" (_sys_arg3), "r" (_sys_arg4),		\
+			      "r" (_sys_arg5));				\
+	})
+
+#endif /* X86_VDSO_SYS_CALL_H */