If CONFIG_GENERIC_COMPAT_VDSO is enabled, compat vDSO are installed in a compat (32 bit) process instead of sigpage.
Add the necessary code to setup the vDSO required pages.
Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/kernel/vdso.c | 90 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 88 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index aa1fb25a9fe4..ad3a81b2c7ce 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -40,12 +40,22 @@ #include <asm/vdso.h>
extern char vdso_start[], vdso_end[]; +#ifdef CONFIG_COMPAT_VDSO +extern char vdso32_start[], vdso32_end[]; +#endif /* CONFIG_COMPAT_VDSO */
/* vdso_lookup arch_index */ enum arch_vdso_type { ARM64_VDSO = 0, +#ifdef CONFIG_COMPAT_VDSO + ARM64_VDSO32 = 1, +#endif /* CONFIG_COMPAT_VDSO */ }; +#ifdef CONFIG_COMPAT_VDSO +#define VDSO_TYPES (ARM64_VDSO32 + 1) +#else #define VDSO_TYPES (ARM64_VDSO + 1) +#endif /* CONFIG_COMPAT_VDSO */
struct __vdso_abi { const char *name; @@ -64,6 +74,13 @@ static struct __vdso_abi vdso_lookup[VDSO_TYPES] __ro_after_init = { .vdso_code_start = vdso_start, .vdso_code_end = vdso_end, }, +#ifdef CONFIG_COMPAT_VDSO + { + .name = "vdso32", + .vdso_code_start = vdso32_start, + .vdso_code_end = vdso32_end, + }, +#endif /* CONFIG_COMPAT_VDSO */ };
/* @@ -174,24 +191,52 @@ static int __setup_additional_pages(enum arch_vdso_type arch_index, /* * Create and map the vectors page for AArch32 tasks. */ +#ifdef CONFIG_COMPAT_VDSO +static int aarch32_vdso_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + return __vdso_remap(ARM64_VDSO32, sm, new_vma); +} +#endif /* CONFIG_COMPAT_VDSO */ + /* * aarch32_vdso_pages: * 0 - kuser helpers * 1 - sigreturn code + * or (CONFIG_COMPAT_VDSO): + * 0 - kuser helpers + * 1 - vdso data + * 2 - vdso code */ #define C_VECTORS 0 +#ifdef CONFIG_COMPAT_VDSO +#define C_VVAR 1 +#define C_VDSO 2 +#define C_PAGES (C_VDSO + 1) +#else #define C_SIGPAGE 1 #define C_PAGES (C_SIGPAGE + 1) +#endif /* CONFIG_COMPAT_VDSO */ static struct page *aarch32_vdso_pages[C_PAGES] __ro_after_init; -static const struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { +static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { { .name = "[vectors]", /* ABI */ .pages = &aarch32_vdso_pages[C_VECTORS], }, +#ifdef CONFIG_COMPAT_VDSO + { + .name = "[vvar]", + }, + { + .name = "[vdso]", + .mremap = aarch32_vdso_mremap, + }, +#else { .name = "[sigpage]", /* ABI */ .pages = &aarch32_vdso_pages[C_SIGPAGE], }, +#endif /* CONFIG_COMPAT_VDSO */ };
static int aarch32_alloc_kuser_vdso_page(void) @@ -214,7 +259,33 @@ static int aarch32_alloc_kuser_vdso_page(void) return 0; }
-static int __init aarch32_alloc_vdso_pages(void) +#ifdef CONFIG_COMPAT_VDSO +static int __aarch32_alloc_vdso_pages(void) +{ + int ret; + + vdso_lookup[ARM64_VDSO32].dm = &aarch32_vdso_spec[C_VVAR]; + vdso_lookup[ARM64_VDSO32].cm = &aarch32_vdso_spec[C_VDSO]; + + ret = __vdso_init(ARM64_VDSO32); + if (ret) + return ret; + + ret = aarch32_alloc_kuser_vdso_page(); + if (ret) { + unsigned long c_vvar = + (unsigned long)page_to_virt(aarch32_vdso_pages[C_VVAR]); + unsigned long c_vdso = + (unsigned long)page_to_virt(aarch32_vdso_pages[C_VDSO]); + + free_page(c_vvar); + free_page(c_vdso); + } + + return ret; +} +#else +static int __aarch32_alloc_vdso_pages(void) { extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; @@ -235,6 +306,12 @@ static int __init aarch32_alloc_vdso_pages(void)
return ret; } +#endif /* CONFIG_COMPAT_VDSO */ + +static int __init aarch32_alloc_vdso_pages(void) +{ + return __aarch32_alloc_vdso_pages(); +} arch_initcall(aarch32_alloc_vdso_pages);
static int aarch32_kuser_helpers_setup(struct mm_struct *mm) @@ -256,6 +333,7 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm) return PTR_ERR_OR_ZERO(ret); }
+#ifndef CONFIG_COMPAT_VDSO static int aarch32_sigreturn_setup(struct mm_struct *mm) { unsigned long addr; @@ -283,6 +361,7 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm) out: return PTR_ERR_OR_ZERO(ret); } +#endif /* !CONFIG_COMPAT_VDSO */
int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { @@ -296,7 +375,14 @@ int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (ret) goto out;
+#ifdef CONFIG_COMPAT_VDSO + ret = __setup_additional_pages(ARM64_VDSO32, + mm, + bprm, + uses_interp); +#else ret = aarch32_sigreturn_setup(mm); +#endif /* CONFIG_COMPAT_VDSO */
out: up_write(&mm->mmap_sem);