lkml.org 
[lkml]   [2020]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2 03/10] entry: Wire up syscall_work in common entry code
    Date
    Prepare the common entry code to use the SYSCALL_WORK flags. They will
    be defined in subsequent patches for each type of syscall
    work. SYSCALL_WORK_ENTRY/EXIT are defined for the transition, as they
    will replace the TIF_ equivalent defines.

    Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

    ---
    Changes since v2:
    - Fix subsystem prefix (tglx)
    - Fix verb in commit message (tglx)
    - Sort variable declaration (tglx)
    ---
    include/linux/entry-common.h | 3 +++
    kernel/entry/common.c | 15 +++++++++------
    2 files changed, 12 insertions(+), 6 deletions(-)

    diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
    index 1a128baf3628..cbc5c702ee4d 100644
    --- a/include/linux/entry-common.h
    +++ b/include/linux/entry-common.h
    @@ -64,6 +64,9 @@
    (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
    _TIF_SYSCALL_TRACEPOINT | ARCH_SYSCALL_EXIT_WORK)

    +#define SYSCALL_WORK_ENTER (0)
    +#define SYSCALL_WORK_EXIT (0)
    +
    /*
    * TIF flags handled in exit_to_user_mode_loop()
    */
    diff --git a/kernel/entry/common.c b/kernel/entry/common.c
    index bc75c114c1b3..51c25f774791 100644
    --- a/kernel/entry/common.c
    +++ b/kernel/entry/common.c
    @@ -42,7 +42,7 @@ static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
    }

    static long syscall_trace_enter(struct pt_regs *regs, long syscall,
    - unsigned long ti_work)
    + unsigned long ti_work, unsigned long work)
    {
    long ret = 0;

    @@ -74,11 +74,12 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
    static __always_inline long
    __syscall_enter_from_user_work(struct pt_regs *regs, long syscall)
    {
    + unsigned long work = READ_ONCE(current_thread_info()->syscall_work);
    unsigned long ti_work;

    ti_work = READ_ONCE(current_thread_info()->flags);
    - if (ti_work & SYSCALL_ENTER_WORK)
    - syscall = syscall_trace_enter(regs, syscall, ti_work);
    + if (work & SYSCALL_WORK_ENTER || ti_work & SYSCALL_ENTER_WORK)
    + syscall = syscall_trace_enter(regs, syscall, ti_work, work);

    return syscall;
    }
    @@ -225,7 +226,8 @@ static inline bool report_single_step(unsigned long ti_work)
    }
    #endif

    -static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work)
    +static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work,
    + unsigned long work)
    {
    bool step;

    @@ -245,6 +247,7 @@ static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work)
    */
    static void syscall_exit_to_user_mode_prepare(struct pt_regs *regs)
    {
    + unsigned long work = READ_ONCE(current_thread_info()->syscall_work);
    u32 cached_flags = READ_ONCE(current_thread_info()->flags);
    unsigned long nr = syscall_get_nr(current, regs);

    @@ -262,8 +265,8 @@ static void syscall_exit_to_user_mode_prepare(struct pt_regs *regs)
    * enabled, we want to run them exactly once per syscall exit with
    * interrupts enabled.
    */
    - if (unlikely(cached_flags & SYSCALL_EXIT_WORK))
    - syscall_exit_work(regs, cached_flags);
    + if (unlikely(work & SYSCALL_WORK_EXIT || cached_flags & SYSCALL_EXIT_WORK))
    + syscall_exit_work(regs, cached_flags, work);
    }

    __visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs)
    --
    2.29.2
    \
     
     \ /
      Last update: 2020-11-16 19:09    [W:3.486 / U:0.100 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site