diff options
Diffstat (limited to 'arch/um/kernel/skas/syscall.c')
| -rw-r--r-- | arch/um/kernel/skas/syscall.c | 49 |
1 files changed, 43 insertions, 6 deletions
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c index b783ac87d98a..ba7494f9bfe4 100644 --- a/arch/um/kernel/skas/syscall.c +++ b/arch/um/kernel/skas/syscall.c @@ -1,6 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) - * Licensed under the GPL */ #include <linux/kernel.h> @@ -9,7 +9,10 @@ #include <kern_util.h> #include <sysdep/ptrace.h> #include <sysdep/ptrace_user.h> -#include <sysdep/syscalls.h> +#include <linux/time-internal.h> +#include <asm/syscall.h> +#include <asm/unistd.h> +#include <asm/delay.h> void handle_syscall(struct uml_pt_regs *r) { @@ -24,13 +27,47 @@ void handle_syscall(struct uml_pt_regs *r) goto out; /* Do the seccomp check after ptrace; failures should be fast. */ - if (secure_computing(NULL) == -1) + if (secure_computing() == -1) goto out; syscall = UPT_SYSCALL_NR(r); - if (syscall >= 0 && syscall <= __NR_syscall_max) - PT_REGS_SET_SYSCALL_RETURN(regs, - EXECUTE_SYSCALL(syscall, regs)); + + /* + * If no time passes, then sched_yield may not actually yield, causing + * broken spinlock implementations in userspace (ASAN) to hang for long + * periods of time. + */ + if ((time_travel_mode == TT_MODE_INFCPU || + time_travel_mode == TT_MODE_EXTERNAL) && + syscall == __NR_sched_yield) + tt_extra_sched_jiffies += 1; + + if (syscall >= 0 && syscall < __NR_syscalls) { + unsigned long ret; + + ret = (*sys_call_table[syscall])(UPT_SYSCALL_ARG1(®s->regs), + UPT_SYSCALL_ARG2(®s->regs), + UPT_SYSCALL_ARG3(®s->regs), + UPT_SYSCALL_ARG4(®s->regs), + UPT_SYSCALL_ARG5(®s->regs), + UPT_SYSCALL_ARG6(®s->regs)); + + PT_REGS_SET_SYSCALL_RETURN(regs, ret); + + /* + * An error value here can be some form of -ERESTARTSYS + * and then we'd just loop. Make any error syscalls take + * some time, so that it won't just loop if something is + * not ready, and hopefully other things will make some + * progress. + */ + if (IS_ERR_VALUE(ret) && + (time_travel_mode == TT_MODE_INFCPU || + time_travel_mode == TT_MODE_EXTERNAL)) { + um_udelay(1); + schedule(); + } + } out: syscall_trace_leave(regs); |