From: Jisheng Zhang <jszhang@kernel.org>
Date: Fri, 5 Jul 2024 17:02:10 +0000 (+0800)
Subject: riscv: define ILLEGAL_POINTER_VALUE for 64bit
X-Git-Tag: v6.12-rc1~76^2~20
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5c178472af247c7b50f962495bb7462ba453b9fb;p=thirdparty%2Fkernel%2Flinux.git

riscv: define ILLEGAL_POINTER_VALUE for 64bit

This is used in poison.h for poison pointer offset. Based on current
SV39, SV48 and SV57 vm layout, 0xdead000000000000 is a proper value
that is not mappable, this can avoid potentially turning an oops to
an expolit.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Fixes: fbe934d69eb7 ("RISC-V: Build Infrastructure")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240705170210.3236-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
---

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 4871220061c45..31d9417923697 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -320,6 +320,11 @@ config GENERIC_HWEIGHT
 config FIX_EARLYCON_MEM
 	def_bool MMU
 
+config ILLEGAL_POINTER_VALUE
+	hex
+	default 0 if 32BIT
+	default 0xdead000000000000 if 64BIT
+
 config PGTABLE_LEVELS
 	int
 	default 5 if 64BIT