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ptrace: Migrate to use SYSCALL_TRACE flag

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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_TRACE, 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 <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-7-krisman@collabora.com
This commit is contained in:
Gabriel Krisman Bertazi 2020-11-16 12:42:02 -05:00 • committed by Thomas Gleixner
parent 524666cb5d
commit 64c19ba29b
7 changed files with 31 additions and 25 deletions
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10
include/linux/entry-common.h
View file

@ -41,7 +41,7 @@
#endif
#define SYSCALL_ENTER_WORK \
(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
(_TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_EMU | \
ARCH_SYSCALL_ENTER_WORK)
@ -53,12 +53,14 @@
#endif
#define SYSCALL_EXIT_WORK \
(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
(_TIF_SYSCALL_AUDIT | \
ARCH_SYSCALL_EXIT_WORK)
#define SYSCALL_WORK_ENTER (SYSCALL_WORK_SECCOMP | \
SYSCALL_WORK_SYSCALL_TRACEPOINT)
#define SYSCALL_WORK_EXIT (SYSCALL_WORK_SYSCALL_TRACEPOINT)
SYSCALL_WORK_SYSCALL_TRACEPOINT | \
SYSCALL_WORK_SYSCALL_TRACE)
#define SYSCALL_WORK_EXIT (SYSCALL_WORK_SYSCALL_TRACEPOINT | \
SYSCALL_WORK_SYSCALL_TRACE)
/*
* TIF flags handled in exit_to_user_mode_loop()

2
include/linux/thread_info.h
View file

@ -38,10 +38,12 @@ enum {
enum syscall_work_bit {
SYSCALL_WORK_BIT_SECCOMP,
SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
SYSCALL_WORK_BIT_SYSCALL_TRACE,
};
#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)
#include <asm/thread_info.h>

17
include/linux/tracehook.h
View file

@ -83,11 +83,12 @@ static inline int ptrace_report_syscall(struct pt_regs *regs,
* tracehook_report_syscall_entry - task is about to attempt a system call
* @regs: user register state of current task
*
* This will be called if %TIF_SYSCALL_TRACE or %TIF_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, preventing the system call from beginning.
* This will be called if %SYSCALL_WORK_SYSCALL_TRACE or
* %TIF_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,
* preventing the system call from beginning.
*
* Returns zero normally, or nonzero if the calling arch code should abort
* the system call. That must prevent normal entry so no system call is
@ -109,15 +110,15 @@ static inline __must_check int tracehook_report_syscall_entry(
* @regs: user register state of current task
* @step: nonzero if simulating single-step or block-step
*
* This will be called if %TIF_SYSCALL_TRACE has been set, when the
* current task has just finished an attempted system call. Full
* This will be called if %SYSCALL_WORK_SYSCALL_TRACE has been set, when
* the current task has just finished an attempted system call. Full
* user register state is available here. It is safe to block here,
* preventing signals from being processed.
*
* If @step is nonzero, this report is also in lieu of the normal
* trap that would follow the system call instruction because
* user_enable_block_step() or user_enable_single_step() was used.
* In this case, %TIF_SYSCALL_TRACE might not be set.
* In this case, %SYSCALL_WORK_SYSCALL_TRACE might not be set.
*
* Called without locks, just before checking for pending signals.
*/