diff options
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 48 |
1 files changed, 34 insertions, 14 deletions
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 03b99164f7f4..e277105fb87a 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -285,22 +285,44 @@ void tls_preserve_current_state(void); .fpsimd_cpu = NR_CPUS, \ } -static inline void start_thread_common(struct pt_regs *regs, unsigned long pc) +static inline void start_thread_common(struct pt_regs *regs, unsigned long pc, + unsigned long pstate) { - s32 previous_syscall = regs->syscallno; - memset(regs, 0, sizeof(*regs)); - regs->syscallno = previous_syscall; - regs->pc = pc; + /* + * Ensure all GPRs are zeroed, and initialize PC + PSTATE. + * The SP (or compat SP) will be initialized later. + */ + regs->user_regs = (struct user_pt_regs) { + .pc = pc, + .pstate = pstate, + }; + + /* + * To allow the syscalls:sys_exit_execve tracepoint we need to preserve + * syscallno, but do not need orig_x0 or the original GPRs. + */ + regs->orig_x0 = 0; + /* + * An exec from a kernel thread won't have an existing PMR value. + */ if (system_uses_irq_prio_masking()) regs->pmr = GIC_PRIO_IRQON; + + /* + * The pt_regs::stackframe field must remain valid throughout this + * function as a stacktrace can be taken at any time. Any user or + * kernel task should have a valid final frame. + */ + WARN_ON_ONCE(regs->stackframe.record.fp != 0); + WARN_ON_ONCE(regs->stackframe.record.lr != 0); + WARN_ON_ONCE(regs->stackframe.type != FRAME_META_TYPE_FINAL); } static inline void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) { - start_thread_common(regs, pc); - regs->pstate = PSR_MODE_EL0t; + start_thread_common(regs, pc, PSR_MODE_EL0t); spectre_v4_enable_task_mitigation(current); regs->sp = sp; } @@ -309,15 +331,13 @@ static inline void start_thread(struct pt_regs *regs, unsigned long pc, static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) { - start_thread_common(regs, pc); - regs->pstate = PSR_AA32_MODE_USR; + unsigned long pstate = PSR_AA32_MODE_USR; if (pc & 1) - regs->pstate |= PSR_AA32_T_BIT; - -#ifdef __AARCH64EB__ - regs->pstate |= PSR_AA32_E_BIT; -#endif + pstate |= PSR_AA32_T_BIT; + if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + pstate |= PSR_AA32_E_BIT; + start_thread_common(regs, pc, pstate); spectre_v4_enable_task_mitigation(current); regs->compat_sp = sp; } |