Merge tag 'x86_vdso_for_v6.3_rc1' of git://git.kernel.org/pub/scm/lin…

…ux/kernel/git/tip/tip Pull x86 vdso updates from Borislav Petkov: - Add getcpu support for the 32-bit version of the vDSO - Some smaller fixes * tag 'x86_vdso_for_v6.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Fix -Wmissing-prototypes warnings x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu selftests: Emit a warning if getcpu() is missing on 32bit x86/vdso: Provide getcpu for x86-32. x86/cpu: Provide the full setup for getcpu() on x86-32 x86/vdso: Move VDSO image init to vdso2c generated code
mariux64 · Feb 21, 2023 · 3f0b090 · 3f0b090
2 parents efebca0 + dac0da4
commit 3f0b090
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Showing 16 changed files with 57 additions and 68 deletions.
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
@@ -29,7 +29,7 @@ VDSO32-$(CONFIG_IA32_EMULATION)	:= y
 # files to link into the vdso
 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
 vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
-vobjs32-y += vdso32/vclock_gettime.o
+vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o
 vobjs-$(CONFIG_X86_SGX)	+= vsgx.o
 
 # files to link into kernel
@@ -104,6 +104,7 @@ $(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO
 CFLAGS_REMOVE_vclock_gettime.o = -pg
 CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
 CFLAGS_REMOVE_vgetcpu.o = -pg
+CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg
 CFLAGS_REMOVE_vsgx.o = -pg
 
 #

diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
@@ -179,6 +179,7 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 
 	fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
 	fprintf(outfile, "#include <linux/linkage.h>\n");
+	fprintf(outfile, "#include <linux/init.h>\n");
 	fprintf(outfile, "#include <asm/page_types.h>\n");
 	fprintf(outfile, "#include <asm/vdso.h>\n");
 	fprintf(outfile, "\n");
@@ -218,5 +219,10 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 			fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
 				required_syms[i].name, (int64_t)syms[i]);
 	}
+	fprintf(outfile, "};\n\n");
+	fprintf(outfile, "static __init int init_%s(void) {\n", image_name);
+	fprintf(outfile, "\treturn init_vdso_image(&%s);\n", image_name);
 	fprintf(outfile, "};\n");
+	fprintf(outfile, "subsys_initcall(init_%s);\n", image_name);
+
 }
diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c
@@ -51,17 +51,8 @@ __setup("vdso32=", vdso32_setup);
 __setup_param("vdso=", vdso_setup, vdso32_setup, 0);
 #endif
 
-int __init sysenter_setup(void)
-{
-	init_vdso_image(&vdso_image_32);
-
-	return 0;
-}
-
 #ifdef CONFIG_X86_64
 
-subsys_initcall(sysenter_setup);
-
 #ifdef CONFIG_SYSCTL
 /* Register vsyscall32 into the ABI table */
 #include <linux/sysctl.h>

diff --git a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef CONFIG_X86_64
+
+/*
+ * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
+ * configuration
+ */
+#undef CONFIG_64BIT
+#undef CONFIG_X86_64
+#undef CONFIG_COMPAT
+#undef CONFIG_PGTABLE_LEVELS
+#undef CONFIG_ILLEGAL_POINTER_VALUE
+#undef CONFIG_SPARSEMEM_VMEMMAP
+#undef CONFIG_NR_CPUS
+#undef CONFIG_PARAVIRT_XXL
+
+#define CONFIG_X86_32 1
+#define CONFIG_PGTABLE_LEVELS 2
+#define CONFIG_PAGE_OFFSET 0
+#define CONFIG_ILLEGAL_POINTER_VALUE 0
+#define CONFIG_NR_CPUS 1
+
+#define BUILD_VDSO32_64
+
+#endif
diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
@@ -1,29 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0
 #define BUILD_VDSO32
-
-#ifdef CONFIG_X86_64
-
-/*
- * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
- * configuration
- */
-#undef CONFIG_64BIT
-#undef CONFIG_X86_64
-#undef CONFIG_COMPAT
-#undef CONFIG_PGTABLE_LEVELS
-#undef CONFIG_ILLEGAL_POINTER_VALUE
-#undef CONFIG_SPARSEMEM_VMEMMAP
-#undef CONFIG_NR_CPUS
-#undef CONFIG_PARAVIRT_XXL
-
-#define CONFIG_X86_32 1
-#define CONFIG_PGTABLE_LEVELS 2
-#define CONFIG_PAGE_OFFSET 0
-#define CONFIG_ILLEGAL_POINTER_VALUE 0
-#define CONFIG_NR_CPUS 1
-
-#define BUILD_VDSO32_64
-
-#endif
-
+#include "fake_32bit_build.h"
 #include "../vclock_gettime.c"
diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
@@ -28,6 +28,7 @@ VERSION
 		__vdso_time;
 		__vdso_clock_getres;
 		__vdso_clock_gettime64;
+		__vdso_getcpu;
 	};
 
 	LINUX_2.5 {

diff --git a/arch/x86/entry/vdso/vdso32/vgetcpu.c b/arch/x86/entry/vdso/vdso32/vgetcpu.c
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "fake_32bit_build.h"
+#include "../vgetcpu.c"
diff --git a/arch/x86/entry/vdso/vgetcpu.c b/arch/x86/entry/vdso/vgetcpu.c
@@ -7,8 +7,7 @@
 
 #include <linux/kernel.h>
 #include <linux/getcpu.h>
-#include <linux/time.h>
-#include <asm/vgtod.h>
+#include <asm/segment.h>
 
 notrace long
 __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
@@ -44,13 +44,16 @@ unsigned int vclocks_used __read_mostly;
 unsigned int __read_mostly vdso64_enabled = 1;
 #endif
 
-void __init init_vdso_image(const struct vdso_image *image)
+int __init init_vdso_image(const struct vdso_image *image)
 {
+	BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32);
 	BUG_ON(image->size % PAGE_SIZE != 0);
 
 	apply_alternatives((struct alt_instr *)(image->data + image->alt),
 			   (struct alt_instr *)(image->data + image->alt +
 						image->alt_len));
+
+	return 0;
 }
 
 static const struct vm_special_mapping vvar_mapping;
@@ -418,18 +421,4 @@ static __init int vdso_setup(char *s)
 	return 1;
 }
 __setup("vdso=", vdso_setup);
-
-static int __init init_vdso(void)
-{
-	BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32);
-
-	init_vdso_image(&vdso_image_64);
-
-#ifdef CONFIG_X86_X32_ABI
-	init_vdso_image(&vdso_image_x32);
-#endif
-
-	return 0;
-}
-subsys_initcall(init_vdso);
 #endif /* CONFIG_X86_64 */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
@@ -542,7 +542,6 @@ enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
 			 IDLE_POLL};
 
 extern void enable_sep_cpu(void);
-extern int sysenter_setup(void);
 
 
 /* Defined in head.S */

diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
@@ -96,7 +96,7 @@
  *
  *  26 - ESPFIX small SS
  *  27 - per-cpu			[ offset to per-cpu data area ]
- *  28 - unused
+ *  28 - VDSO getcpu
  *  29 - unused
  *  30 - unused
  *  31 - TSS for double fault handler
@@ -119,6 +119,7 @@
 
 #define GDT_ENTRY_ESPFIX_SS		26
 #define GDT_ENTRY_PERCPU		27
+#define GDT_ENTRY_CPUNODE		28
 
 #define GDT_ENTRY_DOUBLEFAULT_TSS	31
 
@@ -159,6 +160,8 @@
 # define __KERNEL_PERCPU		0
 #endif
 
+#define __CPUNODE_SEG			(GDT_ENTRY_CPUNODE*8 + 3)
+
 #else /* 64-bit: */
 
 #include <asm/cache.h>
@@ -226,8 +229,6 @@
 #define GDT_ENTRY_TLS_ENTRIES		3
 #define TLS_SIZE			(GDT_ENTRY_TLS_ENTRIES* 8)
 
-#ifdef CONFIG_X86_64
-
 /* Bit size and mask of CPU number stored in the per CPU data (and TSC_AUX) */
 #define VDSO_CPUNODE_BITS		12
 #define VDSO_CPUNODE_MASK		0xfff
@@ -265,7 +266,6 @@ static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node)
 }
 
 #endif /* !__ASSEMBLY__ */
-#endif /* CONFIG_X86_64 */
 
 #ifdef __KERNEL__
 

diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
@@ -45,7 +45,7 @@ extern const struct vdso_image vdso_image_x32;
 extern const struct vdso_image vdso_image_32;
 #endif
 
-extern void __init init_vdso_image(const struct vdso_image *image);
+extern int __init init_vdso_image(const struct vdso_image *image);
 
 extern int map_vdso_once(const struct vdso_image *image, unsigned long addr);
 

diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -318,6 +318,8 @@ u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
 }
 #define vdso_calc_delta vdso_calc_delta
 
+int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts);
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */
diff --git a/arch/x86/include/asm/vdso/processor.h b/arch/x86/include/asm/vdso/processor.h
@@ -18,6 +18,10 @@ static __always_inline void cpu_relax(void)
 	rep_nop();
 }
 
+struct getcpu_cache;
+
+notrace long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __ASM_VDSO_PROCESSOR_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
@@ -1958,7 +1958,6 @@ void __init identify_boot_cpu(void)
 	if (HAS_KERNEL_IBT && cpu_feature_enabled(X86_FEATURE_IBT))
 		pr_info("CET detected: Indirect Branch Tracking enabled\n");
 #ifdef CONFIG_X86_32
-	sysenter_setup();
 	enable_sep_cpu();
 #endif
 	cpu_detect_tlb(&boot_cpu_data);
@@ -2130,7 +2129,6 @@ static void wait_for_master_cpu(int cpu)
 #endif
 }
 
-#ifdef CONFIG_X86_64
 static inline void setup_getcpu(int cpu)
 {
 	unsigned long cpudata = vdso_encode_cpunode(cpu, early_cpu_to_node(cpu));
@@ -2152,6 +2150,7 @@ static inline void setup_getcpu(int cpu)
 	write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_CPUNODE, &d, DESCTYPE_S);
 }
 
+#ifdef CONFIG_X86_64
 static inline void ucode_cpu_init(int cpu)
 {
 	if (cpu)
@@ -2171,8 +2170,6 @@ static inline void tss_setup_ist(struct tss_struct *tss)
 
 #else /* CONFIG_X86_64 */
 
-static inline void setup_getcpu(int cpu) { }
-
 static inline void ucode_cpu_init(int cpu)
 {
 	show_ucode_info_early();

diff --git a/tools/testing/selftests/x86/test_vsyscall.c b/tools/testing/selftests/x86/test_vsyscall.c
@@ -92,11 +92,8 @@ static void init_vdso(void)
 		printf("[WARN]\tfailed to find time in vDSO\n");
 
 	vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu");
-	if (!vdso_getcpu) {
-		/* getcpu() was never wired up in the 32-bit vDSO. */
-		printf("[%s]\tfailed to find getcpu in vDSO\n",
-		       sizeof(long) == 8 ? "WARN" : "NOTE");
-	}
+	if (!vdso_getcpu)
+		printf("[WARN]\tfailed to find getcpu in vDSO\n");
 }
 
 static int init_vsys(void)