linux-kernel - [PATCH v7 13/25] arm64: elf: vDSO code page discovery

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190621095252.32307-14-vincenzo.frascino@arm.com>
Date:   Fri, 21 Jun 2019 10:52:40 +0100
From:   Vincenzo Frascino <vincenzo.frascino@....com>
To:     linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-mips@...r.kernel.org,
        linux-kselftest@...r.kernel.org
Cc:     Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Arnd Bergmann <arnd@...db.de>,
        Russell King <linux@...linux.org.uk>,
        Ralf Baechle <ralf@...ux-mips.org>,
        Paul Burton <paul.burton@...s.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Mark Salyzyn <salyzyn@...roid.com>,
        Peter Collingbourne <pcc@...gle.com>,
        Shuah Khan <shuah@...nel.org>,
        Dmitry Safonov <0x7f454c46@...il.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Huw Davies <huw@...eweavers.com>,
        Shijith Thotton <sthotton@...vell.com>,
        Andre Przywara <andre.przywara@....com>
Subject: [PATCH v7 13/25] arm64: elf: vDSO code page discovery

Like in normal vDSOs, when compat vDSOs are enabled the auxiliary
vector symbol AT_SYSINFO_EHDR needs to point at the address of the
vDSO code, to allow the dynamic linker to find it.

Add the necessary code to the elf arm64 module to make this possible.

Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@....com>
Tested-by: Shijith Thotton <sthotton@...vell.com>
Tested-by: Andre Przywara <andre.przywara@....com>
---
 arch/arm64/include/asm/elf.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 355d120b78cb..34cabaf78011 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -213,7 +213,21 @@ typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
 ({									\
 	set_thread_flag(TIF_32BIT);					\
  })
+#ifdef CONFIG_GENERIC_COMPAT_VDSO
+#define COMPAT_ARCH_DLINFO						\
+do {									\
+	/*								\
+	 * Note that we use Elf64_Off instead of elf_addr_t because	\
+	 * elf_addr_t in compat is defined as Elf32_Addr and casting	\
+	 * current->mm->context.vdso to it triggers a cast warning of	\
+	 * cast from pointer to integer of different size.		\
+	 */								\
+	NEW_AUX_ENT(AT_SYSINFO_EHDR,					\
+			(Elf64_Off)current->mm->context.vdso);		\
+} while (0)
+#else
 #define COMPAT_ARCH_DLINFO
+#endif
 extern int aarch32_setup_additional_pages(struct linux_binprm *bprm,
 					  int uses_interp);
 #define compat_arch_setup_additional_pages \
-- 
2.21.0