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Commit f01703b3 authored by Vincenzo Frascino's avatar Vincenzo Frascino Committed by Thomas Gleixner
Browse files

arm64: compat: Get sigreturn trampolines from vDSO 



When the compat vDSO is enabled, the sigreturn trampolines are not
anymore available through [sigpage] but through [vdso].

Add the relevant code the enable the feature.

Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarShijith Thotton <sthotton@marvell.com>
Tested-by: default avatarAndre Przywara <andre.przywara@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Huw Davies <huw@codeweavers.com>
Link: https://lkml.kernel.org/r/20190621095252.32307-15-vincenzo.frascino@arm.com
parent 1e3f17f5

arch/arm64/include/asm/vdso.h

+3 −0
Original line number Diff line number Diff line
@@ -17,6 +17,9 @@ 
#ifndef __ASSEMBLY__



#include <generated/vdso-offsets.h>

#ifdef CONFIG_COMPAT_VDSO

#include <generated/vdso32-offsets.h>

#endif



#define VDSO_SYMBOL(base, name)						   \

({									   \

arch/arm64/kernel/signal32.c

+26 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <asm/traps.h>

#include <linux/uaccess.h>

#include <asm/unistd.h>

#include <asm/vdso.h>



struct compat_vfp_sigframe {

	compat_ulong_t	magic;
@@ -341,6 +342,30 @@ 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_COMPAT_VDSO

		void *vdso_base = current->mm->context.vdso;

		void *vdso_trampoline;



		if (ka->sa.sa_flags & SA_SIGINFO) {

			if (thumb) {

				vdso_trampoline = VDSO_SYMBOL(vdso_base,

							compat_rt_sigreturn_thumb);

			} else {

				vdso_trampoline = VDSO_SYMBOL(vdso_base,

							compat_rt_sigreturn_arm);

			}

		} else {

			if (thumb) {

				vdso_trampoline = VDSO_SYMBOL(vdso_base,

							compat_sigreturn_thumb);

			} else {

				vdso_trampoline = VDSO_SYMBOL(vdso_base,

							compat_sigreturn_arm);

			}

		}



		retcode = ptr_to_compat(vdso_trampoline) + thumb;

#else

		unsigned int idx = thumb << 1;



		if (ka->sa.sa_flags & SA_SIGINFO)
@@ -348,6 +373,7 @@ static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka, 


		retcode = (unsigned long)current->mm->context.vdso +

			  (idx << 2) + thumb;

#endif

	}



	regs->regs[0]	= usig;