Commit-ID: 7c1deeeb01308426a27a70d5a506aa5fae66dc62 Gitweb: https://git.kernel.org/tip/7c1deeeb01308426a27a70d5a506aa5fae66dc62 Author: Vincenzo Frascino <vincenzo.frasc...@arm.com> AuthorDate: Fri, 21 Jun 2019 10:52:39 +0100 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Sat, 22 Jun 2019 21:21:08 +0200
arm64: compat: VDSO setup for compat layer If CONFIG_GENERIC_COMPAT_VDSO is enabled, compat vDSO is installed in a compat (32 bit) process instead of sigpage. Add the necessary code to setup the vDSO required pages. Signed-off-by: Vincenzo Frascino <vincenzo.frasc...@arm.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Tested-by: Shijith Thotton <sthot...@marvell.com> Tested-by: Andre Przywara <andre.przyw...@arm.com> Cc: linux-a...@vger.kernel.org Cc: linux-arm-ker...@lists.infradead.org Cc: linux-m...@vger.kernel.org Cc: linux-kselft...@vger.kernel.org Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Will Deacon <will.dea...@arm.com> Cc: Arnd Bergmann <a...@arndb.de> Cc: Russell King <li...@armlinux.org.uk> Cc: Ralf Baechle <r...@linux-mips.org> Cc: Paul Burton <paul.bur...@mips.com> Cc: Daniel Lezcano <daniel.lezc...@linaro.org> Cc: Mark Salyzyn <saly...@android.com> Cc: Peter Collingbourne <p...@google.com> Cc: Shuah Khan <sh...@kernel.org> Cc: Dmitry Safonov <0x7f454...@gmail.com> Cc: Rasmus Villemoes <li...@rasmusvillemoes.dk> Cc: Huw Davies <h...@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-13-vincenzo.frasc...@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 be23efc3f60d..354b11e27c07 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -29,12 +29,22 @@ #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; @@ -53,6 +63,13 @@ 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 */ }; /* @@ -163,24 +180,52 @@ up_fail: /* * 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) @@ -203,7 +248,33 @@ 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; @@ -224,6 +295,12 @@ 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) @@ -245,6 +322,7 @@ 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; @@ -272,6 +350,7 @@ 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) { @@ -285,7 +364,14 @@ 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);
