diff options
Diffstat (limited to 'arch/x86/entry/common.c')
| -rw-r--r-- | arch/x86/entry/common.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 48512c7944e7..2f84c7ca74ea 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -60,16 +60,10 @@ __visible noinstr void do_syscall_64(unsigned long nr, struct pt_regs *regs) #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) static __always_inline unsigned int syscall_32_enter(struct pt_regs *regs) { - unsigned int nr = (unsigned int)regs->orig_ax; - if (IS_ENABLED(CONFIG_IA32_EMULATION)) current_thread_info()->status |= TS_COMPAT; - /* - * Subtlety here: if ptrace pokes something larger than 2^32-1 into - * orig_ax, the unsigned int return value truncates it. This may - * or may not be necessary, but it matches the old asm behavior. - */ - return (unsigned int)syscall_enter_from_user_mode(regs, nr); + + return (unsigned int)regs->orig_ax; } /* @@ -91,15 +85,29 @@ __visible noinstr void do_int80_syscall_32(struct pt_regs *regs) { unsigned int nr = syscall_32_enter(regs); + /* + * Subtlety here: if ptrace pokes something larger than 2^32-1 into + * orig_ax, the unsigned int return value truncates it. This may + * or may not be necessary, but it matches the old asm behavior. + */ + nr = (unsigned int)syscall_enter_from_user_mode(regs, nr); + do_syscall_32_irqs_on(regs, nr); syscall_exit_to_user_mode(regs); } static noinstr bool __do_fast_syscall_32(struct pt_regs *regs) { - unsigned int nr = syscall_32_enter(regs); + unsigned int nr = syscall_32_enter(regs); int res; + /* + * This cannot use syscall_enter_from_user_mode() as it has to + * fetch EBP before invoking any of the syscall entry work + * functions. + */ + syscall_enter_from_user_mode_prepare(regs); + instrumentation_begin(); /* Fetch EBP from where the vDSO stashed it. */ if (IS_ENABLED(CONFIG_X86_64)) { @@ -122,6 +130,9 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs) return false; } + /* The case truncates any ptrace induced syscall nr > 2^32 -1 */ + nr = (unsigned int)syscall_enter_from_user_mode_work(regs, nr); + /* Now this is just like a normal syscall. */ do_syscall_32_irqs_on(regs, nr); syscall_exit_to_user_mode(regs); |