From mboxrd@z Thu Jan 1 00:00:00 1970 From: kevin.brodsky@arm.com (Kevin Brodsky) Date: Tue, 6 Dec 2016 16:03:52 +0000 Subject: [RFC PATCH v3 10/11] arm64: compat: Use vDSO sigreturn trampolines if available In-Reply-To: <20161206160353.14581-1-kevin.brodsky@arm.com> References: <20161206160353.14581-1-kevin.brodsky@arm.com> Message-ID: <20161206160353.14581-11-kevin.brodsky@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org If the compat vDSO is enabled, it replaces the sigreturn page. Therefore, we use the sigreturn trampolines the vDSO provides instead. Cc: Will Deacon Cc: Catalin Marinas Cc: Nathan Lynch Cc: Christopher Covington Cc: Dmitry Safonov Cc: Jisheng Zhang Signed-off-by: Kevin Brodsky --- 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 281df761e208..b6e8ff7949a4 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; @@ -438,6 +439,19 @@ 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; @@ -445,6 +459,7 @@ 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; -- 2.10.2