diff options
Diffstat (limited to 'arch/loongarch/kernel/syscall.c')
| -rw-r--r-- | arch/loongarch/kernel/syscall.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/loongarch/kernel/syscall.c b/arch/loongarch/kernel/syscall.c index ec17cd5163b7..ba5d0930a74f 100644 --- a/arch/loongarch/kernel/syscall.c +++ b/arch/loongarch/kernel/syscall.c @@ -9,11 +9,14 @@ #include <linux/entry-common.h> #include <linux/errno.h> #include <linux/linkage.h> +#include <linux/objtool.h> +#include <linux/randomize_kstack.h> #include <linux/syscalls.h> #include <linux/unistd.h> #include <asm/asm.h> #include <asm/exception.h> +#include <asm/loongarch.h> #include <asm/signal.h> #include <asm/switch_to.h> #include <asm-generic/syscalls.h> @@ -39,7 +42,7 @@ void *sys_call_table[__NR_syscalls] = { typedef long (*sys_call_fn)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); -void noinstr do_syscall(struct pt_regs *regs) +void noinstr __no_stack_protector do_syscall(struct pt_regs *regs) { unsigned long nr; sys_call_fn syscall_fn; @@ -55,11 +58,28 @@ void noinstr do_syscall(struct pt_regs *regs) nr = syscall_enter_from_user_mode(regs, nr); + add_random_kstack_offset(); + if (nr < NR_syscalls) { syscall_fn = sys_call_table[nr]; regs->regs[4] = syscall_fn(regs->orig_a0, regs->regs[5], regs->regs[6], regs->regs[7], regs->regs[8], regs->regs[9]); } + /* + * This value will get limited by KSTACK_OFFSET_MAX(), which is 10 + * bits. The actual entropy will be further reduced by the compiler + * when applying stack alignment constraints: 16-bytes (i.e. 4-bits) + * aligned, which will remove the 4 low bits from any entropy chosen + * here. + * + * The resulting 6 bits of entropy is seen in SP[9:4]. + */ + choose_random_kstack_offset(drdtime()); + syscall_exit_to_user_mode(regs); } + +#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET +STACK_FRAME_NON_STANDARD(do_syscall); +#endif |