Unverified Commit 048e2906 authored by Yunhui Cui's avatar Yunhui Cui Committed by Palmer Dabbelt
Browse files

riscv: Randomize lower bits of stack address 



Implement arch_align_stack() to randomize the lower bits
of the stack address.

Signed-off-by: default avatarYunhui Cui <cuiyunhui@bytedance.com>
Link: https://lore.kernel.org/r/20240625030502.68988-1-cuiyunhui@bytedance.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 11c2dbd7

arch/riscv/include/asm/exec.h

0 → 100644
+8 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */



#ifndef __ASM_EXEC_H

#define __ASM_EXEC_H



extern unsigned long arch_align_stack(unsigned long sp);



#endif	/* __ASM_EXEC_H */

arch/riscv/kernel/process.c

+9 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/tick.h>

#include <linux/ptrace.h>

#include <linux/uaccess.h>

#include <linux/personality.h>



#include <asm/unistd.h>

#include <asm/processor.h>
@@ -26,6 +27,7 @@ 
#include <asm/cpuidle.h>

#include <asm/vector.h>

#include <asm/cpufeature.h>

#include <asm/exec.h>



#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)

#include <linux/stackprotector.h>
@@ -99,6 +101,13 @@ void show_regs(struct pt_regs *regs) 
		dump_backtrace(regs, NULL, KERN_DEFAULT);

}



unsigned long arch_align_stack(unsigned long sp)

{

	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)

		sp -= get_random_u32_below(PAGE_SIZE);

	return sp & ~0xf;

}



#ifdef CONFIG_COMPAT

static bool compat_mode_supported __read_mostly;