On Tue, Jan 28, 2020 at 12:17:12AM +1000, Nicholas Piggin wrote:
> This incremental patch fixes several soft-mask debug and unsafe
> smp_processor_id messages due to tracing and false positives in
> "unreconciled" code.
>
> It also fixes a bug with syscall tracing functions that set registers
> (e.g., PTRACE_SETREG) not setting GPRs properly.
>
> There was a bug reported with the TM selftests, I haven't been able
> to reproduce that one.
>
> I can squash this into the main patch and resend the series if it
> helps but the incremental helps to see the bug fixes.
There are some whitespace differences between this and the series I have
applied locally. What does it apply to?
Is there some revision of the patchset I missed?
Thanks
Michal
>
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
> ---
> arch/powerpc/include/asm/cputime.h | 39 +++++++++++++++++-------------
> arch/powerpc/kernel/syscall_64.c | 26 ++++++++++++++------
> 2 files changed, 41 insertions(+), 24 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/cputime.h
> b/arch/powerpc/include/asm/cputime.h
> index c43614cffaac..6639a6847cc0 100644
> --- a/arch/powerpc/include/asm/cputime.h
> +++ b/arch/powerpc/include/asm/cputime.h
> @@ -44,6 +44,28 @@ static inline unsigned long cputime_to_usecs(const
> cputime_t ct)
> #ifdef CONFIG_PPC64
> #define get_accounting(tsk) (&get_paca()->accounting)
> static inline void arch_vtime_task_switch(struct task_struct *tsk) { }
> +
> +/*
> + * account_cpu_user_entry/exit runs "unreconciled", so can't trace,
> + * can't use use get_paca()
> + */
> +static notrace inline void account_cpu_user_entry(void)
> +{
> + unsigned long tb = mftb();
> + struct cpu_accounting_data *acct = &local_paca->accounting;
> +
> + acct->utime += (tb - acct->starttime_user);
> + acct->starttime = tb;
> +}
> +static notrace inline void account_cpu_user_exit(void)
> +{
> + unsigned long tb = mftb();
> + struct cpu_accounting_data *acct = &local_paca->accounting;
> +
> + acct->stime += (tb - acct->starttime);
> + acct->starttime_user = tb;
> +}
> +
> #else
> #define get_accounting(tsk) (&task_thread_info(tsk)->accounting)
> /*
> @@ -60,23 +82,6 @@ static inline void arch_vtime_task_switch(struct
> task_struct *prev)
> }
> #endif
>
> -static inline void account_cpu_user_entry(void)
> -{
> - unsigned long tb = mftb();
> - struct cpu_accounting_data *acct = get_accounting(current);
> -
> - acct->utime += (tb - acct->starttime_user);
> - acct->starttime = tb;
> -}
> -static inline void account_cpu_user_exit(void)
> -{
> - unsigned long tb = mftb();
> - struct cpu_accounting_data *acct = get_accounting(current);
> -
> - acct->stime += (tb - acct->starttime);
> - acct->starttime_user = tb;
> -}
> -
> #endif /* __KERNEL__ */
> #else /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
> static inline void account_cpu_user_entry(void)
> diff --git a/arch/powerpc/kernel/syscall_64.c
> b/arch/powerpc/kernel/syscall_64.c
> index 529393a1ff1e..cfe458adde07 100644
> --- a/arch/powerpc/kernel/syscall_64.c
> +++ b/arch/powerpc/kernel/syscall_64.c
> @@ -19,7 +19,8 @@ extern void __noreturn tabort_syscall(void);
>
> typedef long (*syscall_fn)(long, long, long, long, long, long);
>
> -long system_call_exception(long r3, long r4, long r5, long r6, long r7, long
> r8,
> +/* Has to run notrace because it is entered "unreconciled" */
> +notrace long system_call_exception(long r3, long r4, long r5, long r6, long
> r7, long r8,
> unsigned long r0, struct pt_regs *regs)
> {
> unsigned long ti_flags;
> @@ -36,7 +37,7 @@ long system_call_exception(long r3, long r4, long r5, long
> r6, long r7, long r8,
> #ifdef CONFIG_PPC_SPLPAR
> if (IS_ENABLED(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) &&
> firmware_has_feature(FW_FEATURE_SPLPAR)) {
> - struct lppaca *lp = get_lppaca();
> + struct lppaca *lp = local_paca->lppaca_ptr;
>
> if (unlikely(local_paca->dtl_ridx != be64_to_cpu(lp->dtl_idx)))
> accumulate_stolen_time();
> @@ -71,13 +72,22 @@ long system_call_exception(long r3, long r4, long r5,
> long r6, long r7, long r8,
> * We use the return value of do_syscall_trace_enter() as the
> * syscall number. If the syscall was rejected for any reason
> * do_syscall_trace_enter() returns an invalid syscall number
> - * and the test below against NR_syscalls will fail.
> + * and the test against NR_syscalls will fail and the return
> + * value to be used is in regs->gpr[3].
> */
> r0 = do_syscall_trace_enter(regs);
> - }
> -
> - if (unlikely(r0 >= NR_syscalls))
> + if (unlikely(r0 >= NR_syscalls))
> + return regs->gpr[3];
> + r3 = regs->gpr[3];
> + r4 = regs->gpr[4];
> + r5 = regs->gpr[5];
> + r6 = regs->gpr[6];
> + r7 = regs->gpr[7];
> + r8 = regs->gpr[8];
> +
> + } else if (unlikely(r0 >= NR_syscalls)) {
> return -ENOSYS;
> + }
>
> /* May be faster to do array_index_nospec? */
> barrier_nospec();
> @@ -139,8 +149,10 @@ notrace unsigned long syscall_exit_prepare(unsigned long
> r3,
> regs->gpr[3] = r3;
> }
>
> - if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE))
> + if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
> do_syscall_trace_leave(regs);
> + ret |= _TIF_RESTOREALL;
> + }
>
> again:
> local_irq_disable();
> --
> 2.23.0
>
