There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.
Signed-off-by: Michal Suchanek <[email protected]>
---
v2:
- fix 32bit ifdef condition in signal.c
- simplify the compat ifdef condition in vdso.c - 64bit is redundant
- simplify the compat ifdef condition in callchain.c - 64bit is redundant
v3:
- use IS_ENABLED and maybe_unused where possible
- do not ifdef declarations
- clean up Makefile
v4:
- further makefile cleanup
- simplify is_32bit_task conditions
- avoid ifdef in condition by using return
v5:
- avoid unreachable code on 32bit
- make is_current_64bit constant on !COMPAT
- add stub perf_callchain_user_32 to avoid some ifdefs
v6:
- consolidate current_is_64bit
v7:
- remove leftover perf_callchain_user_32 stub from previous series version
v8:
- fix build again - too trigger-happy with stub removal
- remove a vdso.c hunk that causes warning according to kbuild test robot
---
arch/powerpc/include/asm/thread_info.h | 4 +--
arch/powerpc/kernel/Makefile | 7 ++---
arch/powerpc/kernel/entry_64.S | 2 ++
arch/powerpc/kernel/signal.c | 3 +-
arch/powerpc/kernel/syscall_64.c | 6 ++--
arch/powerpc/kernel/vdso.c | 3 +-
arch/powerpc/perf/callchain.c | 39 ++++++++++++++------------
7 files changed, 33 insertions(+), 31 deletions(-)
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 8e1d0195ac36..c128d8a48ea3 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -144,10 +144,10 @@ static inline bool test_thread_local_flags(unsigned int flags)
return (ti->local_flags & flags) != 0;
}
-#ifdef CONFIG_PPC64
+#ifdef CONFIG_COMPAT
#define is_32bit_task() (test_thread_flag(TIF_32BIT))
#else
-#define is_32bit_task() (1)
+#define is_32bit_task() (IS_ENABLED(CONFIG_PPC32))
#endif
#if defined(CONFIG_PPC64)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 1d646a94d96c..9d8772e863b9 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -44,16 +44,15 @@ CFLAGS_btext.o += -DDISABLE_BRANCH_PROFILING
endif
obj-y := cputable.o ptrace.o syscalls.o \
- irq.o align.o signal_32.o pmc.o vdso.o \
+ irq.o align.o signal_$(BITS).o pmc.o vdso.o \
process.o systbl.o idle.o \
signal.o sysfs.o cacheinfo.o time.o \
prom.o traps.o setup-common.o \
udbg.o misc.o io.o misc_$(BITS).o \
of_platform.o prom_parse.o
-obj-$(CONFIG_PPC64) += setup_64.o sys_ppc32.o \
- signal_64.o ptrace32.o \
- paca.o nvram_64.o firmware.o \
+obj-$(CONFIG_PPC64) += setup_64.o paca.o nvram_64.o firmware.o \
syscall_64.o
+obj-$(CONFIG_COMPAT) += sys_ppc32.o ptrace32.o signal_32.o
obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 15bc2a872a76..cd390300930c 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -51,8 +51,10 @@
SYS_CALL_TABLE:
.tc sys_call_table[TC],sys_call_table
+#ifdef CONFIG_COMPAT
COMPAT_SYS_CALL_TABLE:
.tc compat_sys_call_table[TC],compat_sys_call_table
+#endif
/* This value is used to mark exception frames on the stack. */
exception_marker:
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 60436432399f..61678cb0e6a1 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -247,7 +247,6 @@ static void do_signal(struct task_struct *tsk)
sigset_t *oldset = sigmask_to_save();
struct ksignal ksig = { .sig = 0 };
int ret;
- int is32 = is_32bit_task();
BUG_ON(tsk != current);
@@ -277,7 +276,7 @@ static void do_signal(struct task_struct *tsk)
rseq_signal_deliver(&ksig, tsk->thread.regs);
- if (is32) {
+ if (is_32bit_task()) {
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
ret = handle_rt_signal32(&ksig, oldset, tsk);
else
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 3787ec54c727..65cb58b01aea 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -17,7 +17,6 @@ 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, unsigned long r0, struct pt_regs *regs)
{
- unsigned long ti_flags;
syscall_fn f;
BUG_ON(!(regs->msr & MSR_PR));
@@ -60,8 +59,7 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
__hard_irq_enable();
- ti_flags = current_thread_info()->flags;
- if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
+ if (unlikely(current_thread_info()->flags & _TIF_SYSCALL_DOTRACE)) {
/*
* We use the return value of do_syscall_trace_enter() as the
* syscall number. If the syscall was rejected for any reason
@@ -77,7 +75,7 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
/* May be faster to do array_index_nospec? */
barrier_nospec();
- if (unlikely(ti_flags & _TIF_32BIT)) {
+ if (unlikely(is_32bit_task())) {
f = (void *)compat_sys_call_table[r0];
r3 &= 0x00000000ffffffffULL;
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index d60598113a9f..fa8362a8ab7f 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -678,7 +678,8 @@ static void __init vdso_setup_syscall_map(void)
if (sys_call_table[i] != sys_ni_syscall)
vdso_data->syscall_map_64[i >> 5] |=
0x80000000UL >> (i & 0x1f);
- if (compat_sys_call_table[i] != sys_ni_syscall)
+ if (IS_ENABLED(CONFIG_COMPAT) &&
+ compat_sys_call_table[i] != sys_ni_syscall)
vdso_data->syscall_map_32[i >> 5] |=
0x80000000UL >> (i & 0x1f);
#else /* CONFIG_PPC64 */
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index 7863ee0a0e69..2c8b0a9534fd 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -15,7 +15,7 @@
#include <asm/sigcontext.h>
#include <asm/ucontext.h>
#include <asm/vdso.h>
-#ifdef CONFIG_PPC64
+#ifdef CONFIG_COMPAT
#include "../kernel/ppc32.h"
#endif
#include <asm/pte-walk.h>
@@ -275,30 +275,15 @@ static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
}
}
-static inline int current_is_64bit(void)
-{
- /*
- * We can't use test_thread_flag() here because we may be on an
- * interrupt stack, and the thread flags don't get copied over
- * from the thread_info on the main stack to the interrupt stack.
- */
- return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
-}
-
#else /* CONFIG_PPC64 */
static int read_user_stack_slow(void __user *ptr, void *buf, int nb)
{
return 0;
}
-static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
- struct pt_regs *regs)
-{
-}
-
-static inline int current_is_64bit(void)
+static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
{
- return 0;
}
#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE
@@ -309,6 +294,7 @@ static inline int current_is_64bit(void)
#endif /* CONFIG_PPC64 */
+#if defined(CONFIG_PPC32) || defined(CONFIG_COMPAT)
/*
* On 32-bit we just access the address and let hash_page create a
* HPTE if necessary, so there is no need to fall back to reading
@@ -473,6 +459,23 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
sp = next_sp;
}
}
+#else /* 32bit */
+static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
+{}
+#endif /* 32bit */
+
+static inline int current_is_64bit(void)
+{
+ if (!IS_ENABLED(CONFIG_COMPAT))
+ return IS_ENABLED(CONFIG_PPC64);
+ /*
+ * We can't use test_thread_flag() here because we may be on an
+ * interrupt stack, and the thread flags don't get copied over
+ * from the thread_info on the main stack to the interrupt stack.
+ */
+ return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
+}
void
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
--
2.23.0
Le 12/09/2019 à 20:26, Michal Suchánek a écrit :
> On Thu, 12 Sep 2019 20:02:16 +0200
> Christophe Leroy <[email protected]> wrote:
>
>> Le 12/09/2019 à 19:26, Michal Suchanek a écrit :
>>> There are numerous references to 32bit functions in generic and 64bit
>>> code so ifdef them out.
>>>
>>> Signed-off-by: Michal Suchanek <[email protected]>
>>> ---
>>> v2:
>>> - fix 32bit ifdef condition in signal.c
>>> - simplify the compat ifdef condition in vdso.c - 64bit is redundant
>>> - simplify the compat ifdef condition in callchain.c - 64bit is redundant
>>> v3:
>>> - use IS_ENABLED and maybe_unused where possible
>>> - do not ifdef declarations
>>> - clean up Makefile
>>> v4:
>>> - further makefile cleanup
>>> - simplify is_32bit_task conditions
>>> - avoid ifdef in condition by using return
>>> v5:
>>> - avoid unreachable code on 32bit
>>> - make is_current_64bit constant on !COMPAT
>>> - add stub perf_callchain_user_32 to avoid some ifdefs
>>> v6:
>>> - consolidate current_is_64bit
>>> v7:
>>> - remove leftover perf_callchain_user_32 stub from previous series version
>>> v8:
>>> - fix build again - too trigger-happy with stub removal
>>> - remove a vdso.c hunk that causes warning according to kbuild test robot
>>> ---
>>> arch/powerpc/include/asm/thread_info.h | 4 +--
>>> arch/powerpc/kernel/Makefile | 7 ++---
>>> arch/powerpc/kernel/entry_64.S | 2 ++
>>> arch/powerpc/kernel/signal.c | 3 +-
>>> arch/powerpc/kernel/syscall_64.c | 6 ++--
>>> arch/powerpc/kernel/vdso.c | 3 +-
>>> arch/powerpc/perf/callchain.c | 39 ++++++++++++++------------
>>> 7 files changed, 33 insertions(+), 31 deletions(-)
>>>
>>> diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
>>> index 8e1d0195ac36..c128d8a48ea3 100644
>>> --- a/arch/powerpc/include/asm/thread_info.h
>>> +++ b/arch/powerpc/include/asm/thread_info.h
>>> @@ -144,10 +144,10 @@ static inline bool test_thread_local_flags(unsigned int flags)
>>> return (ti->local_flags & flags) != 0;
>>> }
>>>
>>> -#ifdef CONFIG_PPC64
>>> +#ifdef CONFIG_COMPAT
>>> #define is_32bit_task() (test_thread_flag(TIF_32BIT))
>>> #else
>>> -#define is_32bit_task() (1)
>>> +#define is_32bit_task() (IS_ENABLED(CONFIG_PPC32))
>>> #endif
>>>
>>> #if defined(CONFIG_PPC64)
>>
>> [...]
>>
>>> +static inline int current_is_64bit(void)
>>> +{
>>> + if (!IS_ENABLED(CONFIG_COMPAT))
>>> + return IS_ENABLED(CONFIG_PPC64);
>>> + /*
>>> + * We can't use test_thread_flag() here because we may be on an
>>> + * interrupt stack, and the thread flags don't get copied over
>>> + * from the thread_info on the main stack to the interrupt stack.
>>> + */
>>> + return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
>>> +}
>>
>>
>> Since at least commit ed1cd6deb013 ("powerpc: Activate
>> CONFIG_THREAD_INFO_IN_TASK")
>> [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed1cd6d]
>> the above comment is wrong and current_is_64bit() is equivalent to
>> !is_32bit_task()
>>
>> See https://github.com/linuxppc/issues/issues/275
>>
>> Christophe
>
> I aim at changing the code as little as possible here. A separate patch
> on top removing this function would be ok?
Yes I agree. By making prior to this patch a separate patch which drops
current_is_64bit() would be good. And it would reduce the size of this
patch by approximately one third.
Christophe
>
> Thanks
>
> Michal
>
Le 12/09/2019 à 19:26, Michal Suchanek a écrit :
> There are numerous references to 32bit functions in generic and 64bit
> code so ifdef them out.
>
> Signed-off-by: Michal Suchanek <[email protected]>
> ---
> v2:
> - fix 32bit ifdef condition in signal.c
> - simplify the compat ifdef condition in vdso.c - 64bit is redundant
> - simplify the compat ifdef condition in callchain.c - 64bit is redundant
> v3:
> - use IS_ENABLED and maybe_unused where possible
> - do not ifdef declarations
> - clean up Makefile
> v4:
> - further makefile cleanup
> - simplify is_32bit_task conditions
> - avoid ifdef in condition by using return
> v5:
> - avoid unreachable code on 32bit
> - make is_current_64bit constant on !COMPAT
> - add stub perf_callchain_user_32 to avoid some ifdefs
> v6:
> - consolidate current_is_64bit
> v7:
> - remove leftover perf_callchain_user_32 stub from previous series version
> v8:
> - fix build again - too trigger-happy with stub removal
> - remove a vdso.c hunk that causes warning according to kbuild test robot
> ---
> arch/powerpc/include/asm/thread_info.h | 4 +--
> arch/powerpc/kernel/Makefile | 7 ++---
> arch/powerpc/kernel/entry_64.S | 2 ++
> arch/powerpc/kernel/signal.c | 3 +-
> arch/powerpc/kernel/syscall_64.c | 6 ++--
> arch/powerpc/kernel/vdso.c | 3 +-
> arch/powerpc/perf/callchain.c | 39 ++++++++++++++------------
> 7 files changed, 33 insertions(+), 31 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
> index 8e1d0195ac36..c128d8a48ea3 100644
> --- a/arch/powerpc/include/asm/thread_info.h
> +++ b/arch/powerpc/include/asm/thread_info.h
> @@ -144,10 +144,10 @@ static inline bool test_thread_local_flags(unsigned int flags)
> return (ti->local_flags & flags) != 0;
> }
>
> -#ifdef CONFIG_PPC64
> +#ifdef CONFIG_COMPAT
> #define is_32bit_task() (test_thread_flag(TIF_32BIT))
> #else
> -#define is_32bit_task() (1)
> +#define is_32bit_task() (IS_ENABLED(CONFIG_PPC32))
> #endif
>
> #if defined(CONFIG_PPC64)
[...]
> +static inline int current_is_64bit(void)
> +{
> + if (!IS_ENABLED(CONFIG_COMPAT))
> + return IS_ENABLED(CONFIG_PPC64);
> + /*
> + * We can't use test_thread_flag() here because we may be on an
> + * interrupt stack, and the thread flags don't get copied over
> + * from the thread_info on the main stack to the interrupt stack.
> + */
> + return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
> +}
Since at least commit ed1cd6deb013 ("powerpc: Activate
CONFIG_THREAD_INFO_IN_TASK")
[https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed1cd6d]
the above comment is wrong and current_is_64bit() is equivalent to
!is_32bit_task()
See https://github.com/linuxppc/issues/issues/275
Christophe
On Thu, 12 Sep 2019 20:02:16 +0200
Christophe Leroy <[email protected]> wrote:
> Le 12/09/2019 à 19:26, Michal Suchanek a écrit :
> > There are numerous references to 32bit functions in generic and 64bit
> > code so ifdef them out.
> >
> > Signed-off-by: Michal Suchanek <[email protected]>
> > ---
> > v2:
> > - fix 32bit ifdef condition in signal.c
> > - simplify the compat ifdef condition in vdso.c - 64bit is redundant
> > - simplify the compat ifdef condition in callchain.c - 64bit is redundant
> > v3:
> > - use IS_ENABLED and maybe_unused where possible
> > - do not ifdef declarations
> > - clean up Makefile
> > v4:
> > - further makefile cleanup
> > - simplify is_32bit_task conditions
> > - avoid ifdef in condition by using return
> > v5:
> > - avoid unreachable code on 32bit
> > - make is_current_64bit constant on !COMPAT
> > - add stub perf_callchain_user_32 to avoid some ifdefs
> > v6:
> > - consolidate current_is_64bit
> > v7:
> > - remove leftover perf_callchain_user_32 stub from previous series version
> > v8:
> > - fix build again - too trigger-happy with stub removal
> > - remove a vdso.c hunk that causes warning according to kbuild test robot
> > ---
> > arch/powerpc/include/asm/thread_info.h | 4 +--
> > arch/powerpc/kernel/Makefile | 7 ++---
> > arch/powerpc/kernel/entry_64.S | 2 ++
> > arch/powerpc/kernel/signal.c | 3 +-
> > arch/powerpc/kernel/syscall_64.c | 6 ++--
> > arch/powerpc/kernel/vdso.c | 3 +-
> > arch/powerpc/perf/callchain.c | 39 ++++++++++++++------------
> > 7 files changed, 33 insertions(+), 31 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
> > index 8e1d0195ac36..c128d8a48ea3 100644
> > --- a/arch/powerpc/include/asm/thread_info.h
> > +++ b/arch/powerpc/include/asm/thread_info.h
> > @@ -144,10 +144,10 @@ static inline bool test_thread_local_flags(unsigned int flags)
> > return (ti->local_flags & flags) != 0;
> > }
> >
> > -#ifdef CONFIG_PPC64
> > +#ifdef CONFIG_COMPAT
> > #define is_32bit_task() (test_thread_flag(TIF_32BIT))
> > #else
> > -#define is_32bit_task() (1)
> > +#define is_32bit_task() (IS_ENABLED(CONFIG_PPC32))
> > #endif
> >
> > #if defined(CONFIG_PPC64)
>
> [...]
>
> > +static inline int current_is_64bit(void)
> > +{
> > + if (!IS_ENABLED(CONFIG_COMPAT))
> > + return IS_ENABLED(CONFIG_PPC64);
> > + /*
> > + * We can't use test_thread_flag() here because we may be on an
> > + * interrupt stack, and the thread flags don't get copied over
> > + * from the thread_info on the main stack to the interrupt stack.
> > + */
> > + return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
> > +}
>
>
> Since at least commit ed1cd6deb013 ("powerpc: Activate
> CONFIG_THREAD_INFO_IN_TASK")
> [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed1cd6d]
> the above comment is wrong and current_is_64bit() is equivalent to
> !is_32bit_task()
>
> See https://github.com/linuxppc/issues/issues/275
>
> Christophe
I aim at changing the code as little as possible here. A separate patch
on top removing this function would be ok?
Thanks
Michal
On Thu, 12 Sep 2019 21:36:11 +0200
Christophe Leroy <[email protected]> wrote:
> Le 12/09/2019 à 20:26, Michal Suchánek a écrit :
> > On Thu, 12 Sep 2019 20:02:16 +0200
> > Christophe Leroy <[email protected]> wrote:
> >
> >> Le 12/09/2019 à 19:26, Michal Suchanek a écrit :
> >>> There are numerous references to 32bit functions in generic and 64bit
> >>> code so ifdef them out.
> >>>
> >>> Signed-off-by: Michal Suchanek <[email protected]>
> >>> ---
> >>> v2:
> >>> - fix 32bit ifdef condition in signal.c
> >>> - simplify the compat ifdef condition in vdso.c - 64bit is redundant
> >>> - simplify the compat ifdef condition in callchain.c - 64bit is redundant
> >>> v3:
> >>> - use IS_ENABLED and maybe_unused where possible
> >>> - do not ifdef declarations
> >>> - clean up Makefile
> >>> v4:
> >>> - further makefile cleanup
> >>> - simplify is_32bit_task conditions
> >>> - avoid ifdef in condition by using return
> >>> v5:
> >>> - avoid unreachable code on 32bit
> >>> - make is_current_64bit constant on !COMPAT
> >>> - add stub perf_callchain_user_32 to avoid some ifdefs
> >>> v6:
> >>> - consolidate current_is_64bit
> >>> v7:
> >>> - remove leftover perf_callchain_user_32 stub from previous series version
> >>> v8:
> >>> - fix build again - too trigger-happy with stub removal
> >>> - remove a vdso.c hunk that causes warning according to kbuild test robot
> >>> ---
> >>> arch/powerpc/include/asm/thread_info.h | 4 +--
> >>> arch/powerpc/kernel/Makefile | 7 ++---
> >>> arch/powerpc/kernel/entry_64.S | 2 ++
> >>> arch/powerpc/kernel/signal.c | 3 +-
> >>> arch/powerpc/kernel/syscall_64.c | 6 ++--
> >>> arch/powerpc/kernel/vdso.c | 3 +-
> >>> arch/powerpc/perf/callchain.c | 39 ++++++++++++++------------
> >>> 7 files changed, 33 insertions(+), 31 deletions(-)
> >>>
> >>> diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
> >>> index 8e1d0195ac36..c128d8a48ea3 100644
> >>> --- a/arch/powerpc/include/asm/thread_info.h
> >>> +++ b/arch/powerpc/include/asm/thread_info.h
> >>> @@ -144,10 +144,10 @@ static inline bool test_thread_local_flags(unsigned int flags)
> >>> return (ti->local_flags & flags) != 0;
> >>> }
> >>>
> >>> -#ifdef CONFIG_PPC64
> >>> +#ifdef CONFIG_COMPAT
> >>> #define is_32bit_task() (test_thread_flag(TIF_32BIT))
> >>> #else
> >>> -#define is_32bit_task() (1)
> >>> +#define is_32bit_task() (IS_ENABLED(CONFIG_PPC32))
> >>> #endif
> >>>
> >>> #if defined(CONFIG_PPC64)
> >>
> >> [...]
> >>
> >>> +static inline int current_is_64bit(void)
> >>> +{
> >>> + if (!IS_ENABLED(CONFIG_COMPAT))
> >>> + return IS_ENABLED(CONFIG_PPC64);
> >>> + /*
> >>> + * We can't use test_thread_flag() here because we may be on an
> >>> + * interrupt stack, and the thread flags don't get copied over
> >>> + * from the thread_info on the main stack to the interrupt stack.
> >>> + */
> >>> + return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
> >>> +}
> >>
> >>
> >> Since at least commit ed1cd6deb013 ("powerpc: Activate
> >> CONFIG_THREAD_INFO_IN_TASK")
> >> [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed1cd6d]
> >> the above comment is wrong and current_is_64bit() is equivalent to
> >> !is_32bit_task()
> >>
> >> See https://github.com/linuxppc/issues/issues/275
> >>
> >> Christophe
> >
> > I aim at changing the code as little as possible here. A separate patch
> > on top removing this function would be ok?
>
> Yes I agree. By making prior to this patch a separate patch which drops
> current_is_64bit() would be good. And it would reduce the size of this
> patch by approximately one third.
Indeed, removing it before makes this patch much cleaner.
Thanks
Michal