Re: [PATCH v11 5/8] powerpc/64: make buildable without CONFIG_COMPAT
Michal Suchánek's on March 25, 2020 5:30 am:
> On Tue, Mar 24, 2020 at 06:54:20PM +1000, Nicholas Piggin wrote:
>> Michal Suchanek's on March 19, 2020 10:19 pm:
>> > diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
>> > index 4b0152108f61..a264989626fd 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(, tsk->thread.regs);
>> >
>> > - if (is32) {
>> > + if (is_32bit_task()) {
>> >if (ksig.ka.sa.sa_flags & SA_SIGINFO)
>> >ret = handle_rt_signal32(, oldset, tsk);
>> >else
>>
>> Unnecessary?
>>
>> > diff --git a/arch/powerpc/kernel/syscall_64.c
>> > b/arch/powerpc/kernel/syscall_64.c
>> > index 87d95b455b83..2dcbfe38f5ac 100644
>> > --- a/arch/powerpc/kernel/syscall_64.c
>> > +++ b/arch/powerpc/kernel/syscall_64.c
>> > @@ -24,7 +24,6 @@ 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;
>> >syscall_fn f;
>> >
>> >if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
>> > @@ -68,8 +67,7 @@ notrace long system_call_exception(long r3, long r4,
>> > long r5,
>> >
>> >local_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
>> > @@ -94,7 +92,7 @@ notrace long system_call_exception(long r3, long r4,
>> > long r5,
>> >/* May be faster to do array_index_nospec? */
>> >barrier_nospec();
>> >
>> > - if (unlikely(ti_flags & _TIF_32BIT)) {
>> > + if (unlikely(is_32bit_task())) {
>>
>> Problem is, does this allow the load of ti_flags to be used for both
>> tests, or does test_bit make it re-load?
>>
>> This could maybe be fixed by testing if(IS_ENABLED(CONFIG_COMPAT) &&
> Both points already discussed here:
Agh, I'm hopeless.
I don't think it really resolves this issue. But probably don't have time
to look at generated asm, and might never because it won't really hit
LE unless we add a 32-bit ABI. It's pretty minor though either way.
Sorry for being difficult, I really do like your patches :)
Thanks,
Nick
Re: [PATCH v11 5/8] powerpc/64: make buildable without CONFIG_COMPAT
On Tue, Mar 24, 2020 at 06:54:20PM +1000, Nicholas Piggin wrote:
> Michal Suchanek's on March 19, 2020 10:19 pm:
> > diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
> > index 4b0152108f61..a264989626fd 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(, tsk->thread.regs);
> >
> > - if (is32) {
> > + if (is_32bit_task()) {
> > if (ksig.ka.sa.sa_flags & SA_SIGINFO)
> > ret = handle_rt_signal32(, oldset, tsk);
> > else
>
> Unnecessary?
>
> > diff --git a/arch/powerpc/kernel/syscall_64.c
> > b/arch/powerpc/kernel/syscall_64.c
> > index 87d95b455b83..2dcbfe38f5ac 100644
> > --- a/arch/powerpc/kernel/syscall_64.c
> > +++ b/arch/powerpc/kernel/syscall_64.c
> > @@ -24,7 +24,6 @@ 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;
> > syscall_fn f;
> >
> > if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
> > @@ -68,8 +67,7 @@ notrace long system_call_exception(long r3, long r4, long
> > r5,
> >
> > local_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
> > @@ -94,7 +92,7 @@ notrace long system_call_exception(long r3, long r4, long
> > r5,
> > /* May be faster to do array_index_nospec? */
> > barrier_nospec();
> >
> > - if (unlikely(ti_flags & _TIF_32BIT)) {
> > + if (unlikely(is_32bit_task())) {
>
> Problem is, does this allow the load of ti_flags to be used for both
> tests, or does test_bit make it re-load?
>
> This could maybe be fixed by testing if(IS_ENABLED(CONFIG_COMPAT) &&
Both points already discussed here:
https://lore.kernel.org/linuxppc-dev/13fa324dc879a7f325290bf2e131b87eb491cd7b.1573576649.git.msucha...@suse.de/
Thanks
Michal
Re: [PATCH v11 5/8] powerpc/64: make buildable without CONFIG_COMPAT
Michal Suchanek's on March 19, 2020 10:19 pm:
> diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
> index 4b0152108f61..a264989626fd 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(, tsk->thread.regs);
>
> - if (is32) {
> + if (is_32bit_task()) {
> if (ksig.ka.sa.sa_flags & SA_SIGINFO)
> ret = handle_rt_signal32(, oldset, tsk);
> else
Unnecessary?
> diff --git a/arch/powerpc/kernel/syscall_64.c
> b/arch/powerpc/kernel/syscall_64.c
> index 87d95b455b83..2dcbfe38f5ac 100644
> --- a/arch/powerpc/kernel/syscall_64.c
> +++ b/arch/powerpc/kernel/syscall_64.c
> @@ -24,7 +24,6 @@ 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;
> syscall_fn f;
>
> if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
> @@ -68,8 +67,7 @@ notrace long system_call_exception(long r3, long r4, long
> r5,
>
> local_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
> @@ -94,7 +92,7 @@ notrace long system_call_exception(long r3, long r4, long
> r5,
> /* May be faster to do array_index_nospec? */
> barrier_nospec();
>
> - if (unlikely(ti_flags & _TIF_32BIT)) {
> + if (unlikely(is_32bit_task())) {
Problem is, does this allow the load of ti_flags to be used for both
tests, or does test_bit make it re-load?
This could maybe be fixed by testing if(IS_ENABLED(CONFIG_COMPAT) &&
Other than these, the patches all look pretty good to me.
Thanks,
Nick
[PATCH v11 5/8] powerpc/64: make buildable without CONFIG_COMPAT
There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.
Signed-off-by: Michal Suchanek
---
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
v9:
- removed current_is_64bit in previous patch
v10:
- rebase on top of 70ed86f4de5bd
---
arch/powerpc/include/asm/thread_info.h | 4 ++--
arch/powerpc/kernel/Makefile | 6 +++---
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 | 8 +++-
7 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/thread_info.h
b/arch/powerpc/include/asm/thread_info.h
index a2270749b282..ca6c97025704 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -162,10 +162,10 @@ 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 5700231a8988..98a1c143b613 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -42,16 +42,16 @@ 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-$(CONFIG_PPC64)+= setup_64.o sys_ppc32.o \
- signal_64.o ptrace32.o \
+obj-$(CONFIG_PPC64)+= setup_64.o \
paca.o nvram_64.o firmware.o note.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 4c0d0400e93d..fe1421e08f09 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -52,8 +52,10 @@
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 4b0152108f61..a264989626fd 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(, tsk->thread.regs);
- if (is32) {
+ if (is_32bit_task()) {
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
ret = handle_rt_signal32(, oldset, tsk);
else
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 87d95b455b83..2dcbfe38f5ac 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -24,7 +24,6 @@ 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
[PATCH v11 5/8] powerpc/64: make buildable without CONFIG_COMPAT
There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.
Signed-off-by: Michal Suchanek
---
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
v9:
- removed current_is_64bit in previous patch
v10:
- rebase on top of 70ed86f4de5bd
---
arch/powerpc/include/asm/thread_info.h | 4 ++--
arch/powerpc/kernel/Makefile | 6 +++---
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 | 8 +++-
7 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/thread_info.h
b/arch/powerpc/include/asm/thread_info.h
index a2270749b282..ca6c97025704 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -162,10 +162,10 @@ 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 5700231a8988..98a1c143b613 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -42,16 +42,16 @@ 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-$(CONFIG_PPC64)+= setup_64.o sys_ppc32.o \
- signal_64.o ptrace32.o \
+obj-$(CONFIG_PPC64)+= setup_64.o \
paca.o nvram_64.o firmware.o note.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 4c0d0400e93d..fe1421e08f09 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -52,8 +52,10 @@
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 4b0152108f61..a264989626fd 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(, tsk->thread.regs);
- if (is32) {
+ if (is_32bit_task()) {
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
ret = handle_rt_signal32(, oldset, tsk);
else
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 87d95b455b83..2dcbfe38f5ac 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -24,7 +24,6 @@ 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
