diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ff9b80a0e3e3..cc7a642f8c9d 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -50,6 +50,7 @@ #include <asm/unwind.h> #include <asm/tdx.h> #include <asm/mmu_context.h> +#include <asm/shstk.h> #include "process.h" @@ -121,6 +122,7 @@ void exit_thread(struct task_struct *tsk) free_vm86(t); + shstk_free(tsk); fpu__drop(fpu); } @@ -142,6 +144,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) struct inactive_task_frame *frame; struct fork_frame *fork_frame; struct pt_regs *childregs; + unsigned long new_ssp; int ret = 0; childregs = task_pt_regs(p); @@ -179,7 +182,16 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) frame->flags = X86_EFLAGS_FIXED; #endif - fpu_clone(p, clone_flags, args->fn); + /* + * Allocate a new shadow stack for thread if needed. If shadow stack, + * is disabled, new_ssp will remain 0, and fpu_clone() will know not to + * update it. + */ + new_ssp = shstk_alloc_thread_stack(p, clone_flags, args->stack_size); + if (IS_ERR_VALUE(new_ssp)) + return PTR_ERR((void *)new_ssp); + + fpu_clone(p, clone_flags, args->fn, new_ssp); /* Kernel thread ? */ if (unlikely(p->flags & PF_KTHREAD)) { @@ -225,6 +237,13 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (!ret && unlikely(test_tsk_thread_flag(current, TIF_IO_BITMAP))) io_bitmap_share(p); + /* + * If copy_thread() if failing, don't leak the shadow stack possibly + * allocated in shstk_alloc_thread_stack() above. + */ + if (ret) + shstk_free(p); + return ret; } |