From 35d33c76d68dfacc330a8eb477b51cc647c5a847 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Mon, 6 Dec 2021 11:46:56 +0100 Subject: [PATCH] riscv: Initialize thread pointer before calling C functions Because of the stack canary feature that reads from the current task structure the stack canary value, the thread pointer register "tp" must be set before calling any C function from head.S: by chance, setup_vm and all the functions that it calls does not seem to be part of the functions where the canary check is done, but in the following commits, some functions will. Fixes: f2c9699f65557a31 ("riscv: Add STACKPROTECTOR supported") Signed-off-by: Alexandre Ghiti Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/head.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 273eb0f..b865046 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -298,6 +298,7 @@ clear_bss_done: REG_S a0, (a2) /* Initialize page tables and relocate to virtual addresses */ + la tp, init_task la sp, init_thread_union + THREAD_SIZE XIP_FIXUP_OFFSET sp #ifdef CONFIG_BUILTIN_DTB -- 2.7.4