From d5d44e7e3507b0ad868f68e0c5bca6a57afa1b8b Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sun, 25 Oct 2020 23:50:09 +0100 Subject: ARM: 9013/2: Disable KASan instrumentation for some code Disable instrumentation for arch/arm/boot/compressed/* since that code is executed before the kernel has even set up its mappings and definately out of scope for KASan. Disable instrumentation of arch/arm/vdso/* because that code is not linked with the kernel image, so the KASan management code would fail to link. Disable instrumentation of arch/arm/mm/physaddr.c. See commit ec6d06efb0ba ("arm64: Add support for CONFIG_DEBUG_VIRTUAL") for more details. Disable kasan check in the function unwind_pop_register because it does not matter that kasan checks failed when unwind_pop_register() reads the stack memory of a task. Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: kasan-dev@googlegroups.com Reviewed-by: Ard Biesheuvel Tested-by: Ard Biesheuvel # QEMU/KVM/mach-virt/LPAE/8G Tested-by: Florian Fainelli # Brahma SoCs Tested-by: Ahmad Fatoum # i.MX6Q Reported-by: Florian Fainelli Reported-by: Marc Zyngier Signed-off-by: Abbott Liu Signed-off-by: Florian Fainelli Signed-off-by: Linus Walleij Signed-off-by: Russell King --- arch/arm/kernel/unwind.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel/unwind.c') diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index d2bd0df2318d..f35eb584a18a 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -236,7 +236,11 @@ static int unwind_pop_register(struct unwind_ctrl_block *ctrl, if (*vsp >= (unsigned long *)ctrl->sp_high) return -URC_FAILURE; - ctrl->vrs[reg] = *(*vsp)++; + /* Use READ_ONCE_NOCHECK here to avoid this memory access + * from being tracked by KASAN. + */ + ctrl->vrs[reg] = READ_ONCE_NOCHECK(*(*vsp)); + (*vsp)++; return URC_OK; } -- cgit v1.2.3 From 331b9d02d77e0e33f273d8328d9f5453efddd926 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Tue, 17 Nov 2020 00:49:25 +0100 Subject: ARM: 9026/1: unwind: remove old check for GCC <= 4.2 Since commit 0bddd227f3dc ("Documentation: update for gcc 4.9 requirement") the minimum supported version of GCC is gcc-4.9. It's now safe to remove this code. Link: https://github.com/ClangBuiltLinux/linux/issues/427 Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Signed-off-by: Russell King --- arch/arm/kernel/unwind.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'arch/arm/kernel/unwind.c') diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index f35eb584a18a..59fdf257bf8b 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -18,9 +18,6 @@ #warning Your compiler does not have EABI support. #warning ARM unwind is known to compile only with EABI compilers. #warning Change compiler or disable ARM_UNWIND option. -#elif (__GNUC__ == 4 && __GNUC_MINOR__ <= 2) && !defined(__clang__) -#warning Your compiler is too buggy; it is known to not compile ARM unwind support. -#warning Change compiler or disable ARM_UNWIND option. #endif #endif /* __CHECKER__ */ -- cgit v1.2.3