From bfe00c5bbd9ee37b99c281429556c335271d027b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 11 Aug 2020 18:33:34 -0700 Subject: [PATCH] syscalls: use uaccess_kernel in addr_limit_user_check Patch series "clean up address limit helpers", v2. In preparation for eventually phasing out direct use of set_fs(), this series removes the segment_eq() arch helper that is only used to implement or duplicate the uaccess_kernel() API, and then adds descriptive helpers to force the kernel address limit. This patch (of 6): Use the uaccess_kernel helper instead of duplicating it. [hch@lst.de: arm: don't call addr_limit_user_check for nommu] Link: http://lkml.kernel.org/r/20200721045834.GA9613@lst.de Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Tested-by: Guenter Roeck Acked-by: Linus Torvalds Cc: Nick Hu Cc: Greentime Hu Cc: Vincent Chen Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Geert Uytterhoeven Link: http://lkml.kernel.org/r/20200714105505.935079-1-hch@lst.de Link: http://lkml.kernel.org/r/20200710135706.537715-1-hch@lst.de Link: http://lkml.kernel.org/r/20200710135706.537715-2-hch@lst.de Signed-off-by: Linus Torvalds --- arch/arm/kernel/signal.c | 2 ++ include/linux/syscalls.h | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index ab2568996ddb..c9dc912b83f0 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -713,7 +713,9 @@ struct page *get_signal_page(void) /* Defer to generic check */ asmlinkage void addr_limit_check_failed(void) { +#ifdef CONFIG_MMU addr_limit_user_check(); +#endif } #ifdef CONFIG_DEBUG_RSEQ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index a2429d336593..dc2b827c81e5 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -263,7 +263,7 @@ static inline void addr_limit_user_check(void) return; #endif - if (CHECK_DATA_CORRUPTION(!segment_eq(get_fs(), USER_DS), + if (CHECK_DATA_CORRUPTION(uaccess_kernel(), "Invalid address limit on user-mode return")) force_sig(SIGKILL); -- 2.11.0