The following commit has been merged into the core/entry branch of tip: Commit-ID: 64eb35f701f04b30706e21d1b02636b5d31a37d2 Gitweb: https://git.kernel.org/tip/64eb35f701f04b30706e21d1b02636b5d31a37d2 Author: Gabriel Krisman Bertazi <kris...@collabora.com> AuthorDate: Mon, 16 Nov 2020 12:42:03 -05:00 Committer: Thomas Gleixner <t...@linutronix.de> CommitterDate: Mon, 16 Nov 2020 21:53:16 +01:00
ptrace: Migrate TIF_SYSCALL_EMU to use SYSCALL_WORK flag On architectures using the generic syscall entry code the architecture independent syscall work is moved to flags in thread_info::syscall_work. This removes architecture dependencies and frees up TIF bits. Define SYSCALL_WORK_SYSCALL_EMU, use it in the generic entry code and convert the code which uses the TIF specific helper functions to use the new *_syscall_work() helpers which either resolve to the new mode for users of the generic entry code or to the TIF based functions for the other architectures. Signed-off-by: Gabriel Krisman Bertazi <kris...@collabora.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Andy Lutomirski <l...@kernel.org> Link: https://lore.kernel.org/r/20201116174206.2639648-8-kris...@collabora.com --- include/linux/entry-common.h | 8 ++------ include/linux/thread_info.h | 2 ++ include/linux/tracehook.h | 2 +- kernel/entry/common.c | 19 ++++++++++--------- kernel/fork.c | 4 ++-- kernel/ptrace.c | 10 +++++----- 6 files changed, 22 insertions(+), 23 deletions(-) diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index ae426ab..b30f82b 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -13,10 +13,6 @@ * Define dummy _TIF work flags if not defined by the architecture or for * disabled functionality. */ -#ifndef _TIF_SYSCALL_EMU -# define _TIF_SYSCALL_EMU (0) -#endif - #ifndef _TIF_SYSCALL_AUDIT # define _TIF_SYSCALL_AUDIT (0) #endif @@ -42,7 +38,6 @@ #define SYSCALL_ENTER_WORK \ (_TIF_SYSCALL_AUDIT | \ - _TIF_SYSCALL_EMU | \ ARCH_SYSCALL_ENTER_WORK) /* @@ -58,7 +53,8 @@ #define SYSCALL_WORK_ENTER (SYSCALL_WORK_SECCOMP | \ SYSCALL_WORK_SYSCALL_TRACEPOINT | \ - SYSCALL_WORK_SYSCALL_TRACE) + SYSCALL_WORK_SYSCALL_TRACE | \ + SYSCALL_WORK_SYSCALL_EMU) #define SYSCALL_WORK_EXIT (SYSCALL_WORK_SYSCALL_TRACEPOINT | \ SYSCALL_WORK_SYSCALL_TRACE) diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 761a459..85b8a42 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -39,11 +39,13 @@ enum syscall_work_bit { SYSCALL_WORK_BIT_SECCOMP, SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT, SYSCALL_WORK_BIT_SYSCALL_TRACE, + SYSCALL_WORK_BIT_SYSCALL_EMU, }; #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT) #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE) +#define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU) #include <asm/thread_info.h> diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 3f20368..54b9252 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -84,7 +84,7 @@ static inline int ptrace_report_syscall(struct pt_regs *regs, * @regs: user register state of current task * * This will be called if %SYSCALL_WORK_SYSCALL_TRACE or - * %TIF_SYSCALL_EMU have been set, when the current task has just + * %SYSCALL_WORK_SYSCALL_EMU have been set, when the current task has just * entered the kernel for a system call. Full user register state is * available here. Changing the values in @regs can affect the system * call number and arguments to be tried. It is safe to block here, diff --git a/kernel/entry/common.c b/kernel/entry/common.c index 917328a..90533f3 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -47,9 +47,9 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall, long ret = 0; /* Handle ptrace */ - if (work & SYSCALL_WORK_SYSCALL_TRACE || ti_work & _TIF_SYSCALL_EMU) { + if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)) { ret = arch_syscall_enter_tracehook(regs); - if (ret || (ti_work & _TIF_SYSCALL_EMU)) + if (ret || (work & SYSCALL_WORK_SYSCALL_EMU)) return -1L; } @@ -208,21 +208,22 @@ static void exit_to_user_mode_prepare(struct pt_regs *regs) } #ifndef _TIF_SINGLESTEP -static inline bool report_single_step(unsigned long ti_work) +static inline bool report_single_step(unsigned long work) { return false; } #else /* - * If TIF_SYSCALL_EMU is set, then the only reason to report is when + * If SYSCALL_EMU is set, then the only reason to report is when * TIF_SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall * instruction has been already reported in syscall_enter_from_user_mode(). */ -#define SYSEMU_STEP (_TIF_SINGLESTEP | _TIF_SYSCALL_EMU) - -static inline bool report_single_step(unsigned long ti_work) +static inline bool report_single_step(unsigned long work) { - return (ti_work & SYSEMU_STEP) == _TIF_SINGLESTEP; + if (!(work & SYSCALL_WORK_SYSCALL_EMU)) + return false; + + return !!(current_thread_info()->flags & _TIF_SINGLESTEP); } #endif @@ -236,7 +237,7 @@ static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work, if (work & SYSCALL_WORK_SYSCALL_TRACEPOINT) trace_sys_exit(regs, syscall_get_return_value(current, regs)); - step = report_single_step(ti_work); + step = report_single_step(work); if (step || work & SYSCALL_WORK_SYSCALL_TRACE) arch_syscall_exit_tracehook(regs, step); } diff --git a/kernel/fork.c b/kernel/fork.c index 99f68c2..02b689a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2159,8 +2159,8 @@ static __latent_entropy struct task_struct *copy_process( */ user_disable_single_step(p); clear_task_syscall_work(p, SYSCALL_TRACE); -#ifdef TIF_SYSCALL_EMU - clear_tsk_thread_flag(p, TIF_SYSCALL_EMU); +#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) + clear_task_syscall_work(p, SYSCALL_EMU); #endif clear_tsk_latency_tracing(p); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 55a2bc3..237bcd6 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -118,8 +118,8 @@ void __ptrace_unlink(struct task_struct *child) BUG_ON(!child->ptrace); clear_task_syscall_work(child, SYSCALL_TRACE); -#ifdef TIF_SYSCALL_EMU - clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); +#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) + clear_task_syscall_work(child, SYSCALL_EMU); #endif child->parent = child->real_parent; @@ -816,11 +816,11 @@ static int ptrace_resume(struct task_struct *child, long request, else clear_task_syscall_work(child, SYSCALL_TRACE); -#ifdef TIF_SYSCALL_EMU +#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) - set_tsk_thread_flag(child, TIF_SYSCALL_EMU); + set_task_syscall_work(child, SYSCALL_EMU); else - clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); + clear_task_syscall_work(child, SYSCALL_EMU); #endif if (is_singleblock(request)) {
