From mboxrd@z Thu Jan 1 00:00:00 1970 From: salyzyn@android.com (Mark Salyzyn) Date: Wed, 15 Nov 2017 14:05:11 -0800 Subject: [PATCH 1/6] arm64: compat: Use vDSO sigreturn trampolines if available In-Reply-To: <20171115220529.14458-1-salyzyn@android.com> References: <20171115220529.14458-1-salyzyn@android.com> Message-ID: <20171115220529.14458-2-salyzyn@android.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Kevin Brodsky If the compat vDSO is enabled, it replaces the sigreturn page. Therefore, we use the sigreturn trampolines the vDSO provides instead. Signed-off-by: Kevin Brodsky Signed-off-by: Mark Salyzyn Cc: Catalin Marinas Cc: Will Deacon Cc: Dave Martin Cc: "Eric W. Biederman" Cc: linux-arm-kernel at lists.infradead.org Cc: linux-kernel at vger.kernel.org --- arch/arm64/include/asm/vdso.h | 3 +++ arch/arm64/kernel/signal32.c | 15 +++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/arch/arm64/include/asm/vdso.h b/arch/arm64/include/asm/vdso.h index 839ce0031bd5..f2a952338f1e 100644 --- a/arch/arm64/include/asm/vdso.h +++ b/arch/arm64/include/asm/vdso.h @@ -28,6 +28,9 @@ #ifndef __ASSEMBLY__ #include +#ifdef CONFIG_VDSO32 +#include +#endif #define VDSO_SYMBOL(base, name) \ ({ \ diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c index 4f0c0aa14cba..37095782622d 100644 --- a/arch/arm64/kernel/signal32.c +++ b/arch/arm64/kernel/signal32.c @@ -28,6 +28,7 @@ #include #include #include +#include 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; -- 2.15.0.448.gf294e3d99a-goog