arm64: compat: Add COMPAT_VDSO

index 839ce0031bd5..f2a952338f1e 100644
@@ -28,6 +28,9 @@
 #ifndef __ASSEMBLY__
 
 #include <generated/vdso-offsets.h>
+#ifdef CONFIG_VDSO32
+#include <generated/vdso32-offsets.h>
+#endif
 
 #define VDSO_SYMBOL(base, name)						   \
 ({									   \

index 4f0c0aa14cba..37095782622d 100644
@@ -28,6 +28,7 @@
 #include <asm/signal32.h>
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
+#include <asm/vdso.h>
 
 struct compat_vfp_sigframe {
 	compat_ulong_t	magic;

@@ -433,6 +434,19 @@ static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 		retcode = ptr_to_compat(ka->sa.sa_restorer);
 	} else {
 		/* Set up sigreturn pointer */
+#ifdef CONFIG_VDSO32
+		void *vdso_base = current->mm->context.vdso;
+		void *trampoline =
+			(ka->sa.sa_flags & SA_SIGINFO
+			 ? (thumb
+			    ? VDSO_SYMBOL(vdso_base, compat_rt_sigreturn_thumb)
+			    : VDSO_SYMBOL(vdso_base, compat_rt_sigreturn_arm))
+			 : (thumb
+			    ? VDSO_SYMBOL(vdso_base, compat_sigreturn_thumb)
+			    : VDSO_SYMBOL(vdso_base, compat_sigreturn_arm)));
+
+		retcode = ptr_to_compat(trampoline) + thumb;
+#else
 		void *sigreturn_base = current->mm->context.vdso;
 		unsigned int idx = thumb << 1;
 

@@ -440,6 +454,7 @@ static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 			idx += 3;
 
 		retcode = ptr_to_compat(sigreturn_base) + (idx << 2) + thumb;
+#endif
 	}
 
 	regs->regs[0]	= usig;

index 33be513ef24c..675fa096d4a4 100644
@@ -144,11 +144,12 @@ typedef struct user_fpsimd_state elf_fpregset_t;
 })
 
 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
-#define ARCH_DLINFO							\
+#define _SET_AUX_ENT_VDSO						\
 do {									\
 	NEW_AUX_ENT(AT_SYSINFO_EHDR,					\
-		    (elf_addr_t)current->mm->context.vdso);		\
+		    (Elf64_Off)current->mm->context.vdso);		\
 } while (0)
+#define ARCH_DLINFO _SET_AUX_ENT_VDSO
 
 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES
 struct linux_binprm;

@@ -196,7 +197,11 @@ typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
 ({									\
 	set_thread_flag(TIF_32BIT);					\
  })
+#ifdef CONFIG_VDSO32
+#define COMPAT_ARCH_DLINFO	_SET_AUX_ENT_VDSO
+#else
 #define COMPAT_ARCH_DLINFO
+#endif
 extern int aarch32_setup_vectors_page(struct linux_binprm *bprm,
 				      int uses_interp);
 #define compat_arch_setup_additional_pages \

index 26d510474ffa..48b4111a933f 100644
@@ -39,8 +39,11 @@
 #include <asm/vdso.h>
 #include <asm/vdso_datapage.h>
 
-extern char vdso_start[], vdso_end[];
-static unsigned long vdso_pages __ro_after_init;
+struct vdso_mappings {
+	unsigned long num_code_pages;
+	struct vm_special_mapping data_mapping;
+	struct vm_special_mapping code_mapping;
+};
 
 /*
  * The vDSO data page.

@@ -164,95 +167,114 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
 	return 0;
 }
 
-static struct vm_special_mapping vdso_spec[2] __ro_after_init = {
-	{
-		.name	= "[vvar]",
-	},
-	{
-		.name	= "[vdso]",
-		.mremap = vdso_mremap,
-	},
-};
-
-static int __init vdso_init(void)
+static int __init vdso_mappings_init(const char *name,
+				     const char *code_start,
+				     const char *code_end,
+				     struct vdso_mappings *mappings)
 {
-	int i;
+	unsigned long i, vdso_page;
 	struct page **vdso_pagelist;
 	unsigned long pfn;
 
-	if (memcmp(vdso_start, "\177ELF", 4)) {
-		pr_err("vDSO is not a valid ELF object!\n");
+	if (memcmp(code_start, "\177ELF", 4)) {
+		pr_err("%s is not a valid ELF object!\n", name);
 		return -EINVAL;
 	}
 
-	vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
-	pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n",
-		vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data);
-
-	/* Allocate the vDSO pagelist, plus a page for the data. */
-	vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *),
-				GFP_KERNEL);
+	vdso_pages = (code_end - code_start) >> PAGE_SHIFT;
+	pr_info("%s: %ld pages (%ld code @ %p, %ld data @ %p)\n",
+		name, vdso_pages + 1, vdso_pages, code_start, 1L,
+		vdso_data);
+
+	/*
+	 * Allocate space for storing pointers to the vDSO code pages + the
+	 * data page. The pointers must have the same lifetime as the mappings,
+	 * which are static, so there is no need to keep track of the pointer
+	 * array to free it.
+	 */
+	vdso_pagelist = kmalloc_array(vdso_pages + 1, sizeof(struct page *),
+				      GFP_KERNEL);
 	if (vdso_pagelist == NULL)
 		return -ENOMEM;
 
 	/* Grab the vDSO data page. */
 	vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data));
 
-
 	/* Grab the vDSO code pages. */
-	pfn = sym_to_pfn(vdso_start);
+	pfn = sym_to_pfn(code_start);
 
 	for (i = 0; i < vdso_pages; i++)
 		vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
 
-	vdso_spec[0].pages = &vdso_pagelist[0];
-	vdso_spec[1].pages = &vdso_pagelist[1];
+	/* Populate the special mapping structures */
+	mappings->data_mapping = (struct vm_special_mapping) {
+		.name	= "[vvar]",
+		.pages	= &vdso_pagelist[0],
+	};
+
+	mappings->code_mapping = (struct vm_special_mapping) {
+		.name	= "[vdso]",
+		.pages	= &vdso_pagelist[1],
+	};
 
+	mappings->num_code_pages = vdso_pages;
 	return 0;
 }
+
+static struct vdso_mappings vdso_mappings __ro_after_init;
+
+static int __init vdso_init(void)
+{
+	extern char vdso_start[], vdso_end[];
+
+	return vdso_mappings_init("vdso", vdso_start, vdso_end,
+				  &vdso_mappings);
+}
 arch_initcall(vdso_init);
 
-int arch_setup_additional_pages(struct linux_binprm *bprm,
-				int uses_interp)
+static int vdso_setup(struct mm_struct *mm,
+		      const struct vdso_mappings *mappings)
 {
-	struct mm_struct *mm = current->mm;
 	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
 	void *ret;
 
-	vdso_text_len = vdso_pages << PAGE_SHIFT;
+	vdso_text_len = mappings->num_code_pages << PAGE_SHIFT;
 	/* Be sure to map the data page */
 	vdso_mapping_len = vdso_text_len + PAGE_SIZE;
 
-	if (down_write_killable(&mm->mmap_sem))
-		return -EINTR;
 	vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
-	if (IS_ERR_VALUE(vdso_base)) {
-		ret = ERR_PTR(vdso_base);
-		goto up_fail;
-	}
+	if (IS_ERR_VALUE(vdso_base))
+		ret = PTR_ERR_OR_ZERO(ERR_PTR(vdso_base));
+
 	ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
 				       VM_READ|VM_MAYREAD,
-				       &vdso_spec[0]);
+				       &mappings->data_mapping);
 	if (IS_ERR(ret))
-		goto up_fail;
+		return PTR_ERR_OR_ZERO(ret);
 
 	vdso_base += PAGE_SIZE;
-	mm->context.vdso = (void *)vdso_base;
 	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
 				       VM_READ|VM_EXEC|
 				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
-				       &vdso_spec[1]);
-	if (IS_ERR(ret))
-		goto up_fail;
+				       &mappings->code_mapping);
+	if (!IS_ERR(ret))
+		mm->context.vdso = (void *)vdso_base;
+
+	return PTR_ERR_OR_ZERO(ret);
+}
 
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	int ret;
 
-	up_write(&mm->mmap_sem);
-	return 0;
+	if (down_write_killable(&mm->mmap_sem))
+		return -EINTR;
+
+	ret = vdso_setup(mm, &vdso_mappings);
 
-up_fail:
-	mm->context.vdso = NULL;
 	up_write(&mm->mmap_sem);
-	return PTR_ERR(ret);
+	return ret;
 }
 
 /*

120 lines not on this page · raw message

new file mode 100644
index 000000000000..fe3e216d94d1
@@ -0,0 +1 @@
+#include "../vdso/datapage.h"

new file mode 100644
index 000000000000..b73d4011993d
@@ -0,0 +1,3 @@
+#include "compiler.h"
+#include "datapage.h"
+#include "../../../../lib/vdso/vgettimeofday.c"

index 48b4111a933f..9d44ce962538 100644
@@ -58,6 +58,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data;
 /*
  * Create and map the vectors page for AArch32 tasks.
  */
+#if !defined(CONFIG_VDSO32) || defined(CONFIG_KUSER_HELPERS)
 static struct page *vectors_page[] __ro_after_init;
 static const struct vm_special_mapping compat_vdso_spec[] = {
 	{

@@ -73,6 +74,7 @@ static const struct vm_special_mapping compat_vdso_spec[] = {
 #endif
 };
 static struct page *vectors_page[ARRAY_SIZE(compat_vdso_spec)] __ro_after_init;
+#endif
 
 static int __init alloc_vectors_page(void)
 {

@@ -82,6 +84,7 @@ static int __init alloc_vectors_page(void)
 	unsigned long kuser_vpage;
 #endif
 
+#ifndef CONFIG_VDSO32
 	extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
 	size_t sigret_sz =
 		__aarch32_sigret_code_end - __aarch32_sigret_code_start;

@@ -90,19 +93,24 @@ static int __init alloc_vectors_page(void)
 	sigret_vpage = get_zeroed_page(GFP_ATOMIC);
 	if (!sigret_vpage)
 		return -ENOMEM;
+#endif
 
 #ifdef CONFIG_KUSER_HELPERS
 	kuser_vpage = get_zeroed_page(GFP_ATOMIC);
 	if (!kuser_vpage) {
+#ifndef CONFIG_VDSO32
 		free_page(sigret_vpage);
+#endif
 		return -ENOMEM;
 	}
 #endif
 
+#ifndef CONFIG_VDSO32
 	/* sigreturn code */
 	memcpy((void *)sigret_vpage, __aarch32_sigret_code_start, sigret_sz);
 	flush_icache_range(sigret_vpage, sigret_vpage + PAGE_SIZE);
 	vectors_page[0] = virt_to_page(sigret_vpage);
+#endif
 
 #ifdef CONFIG_KUSER_HELPERS
 	/* kuser helpers */

@@ -116,6 +124,7 @@ static int __init alloc_vectors_page(void)
 }
 arch_initcall(alloc_vectors_page);
 
+#ifndef CONFIG_VDSO32
 int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
 {
 	struct mm_struct *mm = current->mm;

@@ -151,6 +160,7 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
 
 	return PTR_ERR_OR_ZERO(ret);
 }
+#endif /* !CONFIG_VDSO32 */
 #endif /* CONFIG_COMPAT */
 
 static int vdso_mremap(const struct vm_special_mapping *sm,

@@ -221,6 +231,23 @@ static int __init vdso_mappings_init(const char *name,
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
+#ifdef CONFIG_VDSO32
+
+static struct vdso_mappings vdso32_mappings __ro_after_init;
+
+static int __init vdso32_init(void)
+{
+	extern char vdso32_start[], vdso32_end[];
+
+	return vdso_mappings_init("vdso32", vdso32_start, vdso32_end,
+				  &vdso32_mappings);
+}
+arch_initcall(vdso32_init);
+
+#endif /* CONFIG_VDSO32 */
+#endif /* CONFIG_COMPAT */
+
 static struct vdso_mappings vdso_mappings __ro_after_init;
 
 static int __init vdso_init(void)

@@ -263,6 +290,34 @@ static int vdso_setup(struct mm_struct *mm,
 	return PTR_ERR_OR_ZERO(ret);
 }
 
+#ifdef CONFIG_COMPAT
+#ifdef CONFIG_VDSO32
+int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	void *ret;
+
+	if (down_write_killable(&mm->mmap_sem))
+		return -EINTR;
+
+	ret = ERR_PTR(vdso_setup(mm, &vdso32_mappings));
+#ifdef CONFIG_KUSER_HELPERS
+	if (!IS_ERR(ret))
+		/* Map the kuser helpers at the ABI-defined high address. */
+		ret = _install_special_mapping(mm, AARCH32_KUSER_HELPERS_BASE,
+					       PAGE_SIZE,
+					       VM_READ|VM_EXEC|
+					       VM_MAYREAD|VM_MAYEXEC,
+					       &compat_vdso_spec[1]);
+#endif
+
+	up_write(&mm->mmap_sem);
+
+	return PTR_ERR_OR_ZERO(ret);
+}
+#endif /* CONFIG_VDSO32 */
+#endif /* CONFIG_COMPAT */
+
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
 	struct mm_struct *mm = current->mm;