Re: [PATCH v2 3/4] powerpc/64: make buildable without CONFIG_COMPAT
On Wed, 28 Aug 2019 14:49:16 +0200
Christophe Leroy wrote:
> Le 28/08/2019 à 12:30, Michal Suchanek a écrit :
> > There are numerous references to 32bit functions in generic and 64bit
> > code so ifdef them out.
>
> As far as possible, avoid opting things out with ifdefs. Ref
> https://www.kernel.org/doc/html/latest/process/coding-style.html#conditional-compilation
>
> See comment below.
>
> >
> > 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
> > ---
> > arch/powerpc/include/asm/syscall.h | 2 ++
> > arch/powerpc/kernel/Makefile | 15 ---
> > arch/powerpc/kernel/entry_64.S | 2 ++
> > arch/powerpc/kernel/signal.c | 5 +++--
> > arch/powerpc/kernel/syscall_64.c | 5 +++--
> > arch/powerpc/kernel/vdso.c | 4 +++-
> > arch/powerpc/perf/callchain.c | 14 ++
> > 7 files changed, 35 insertions(+), 12 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/syscall.h
> > b/arch/powerpc/include/asm/syscall.h
> > index 38d62acfdce7..3ed3b75541a1 100644
> > --- a/arch/powerpc/include/asm/syscall.h
> > +++ b/arch/powerpc/include/asm/syscall.h
> > @@ -16,7 +16,9 @@
> >
> > /* ftrace syscalls requires exporting the sys_call_table */
> > extern const unsigned long sys_call_table[];
> > +#ifdef CONFIG_COMPAT
> > extern const unsigned long compat_sys_call_table[];
> > +#endif
>
> Leaving the declaration should be harmless.
Yes, it only allows earlier check that the type is not used.
>
> >
> > static inline int syscall_get_nr(struct task_struct *task, struct pt_regs
> > *regs)
> > {
> > diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> > index 1d646a94d96c..b0db365b83d8 100644
> > --- a/arch/powerpc/kernel/Makefile
> > +++ b/arch/powerpc/kernel/Makefile
> > @@ -44,16 +44,25 @@ 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 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 \
> > +ifndef CONFIG_PPC64
> > +obj-y += signal_32.o
> > +else
> > +ifdef CONFIG_COMPAT
> > +obj-y += signal_32.o
> > +endif
> > +endif
> > +obj-$(CONFIG_PPC64)+= setup_64.o signal_64.o \
> >paca.o nvram_64.o firmware.o \
> >syscall_64.o
>
> That's still a bit messy. You could have:
>
> obj-y = +=signal_$(BITS).o
> obj-$(CONFIG_COMPAT) += signal_32.o
>
> > +ifdef CONFIG_COMPAT
> > +obj-$(CONFIG_PPC64)+= sys_ppc32.o ptrace32.o
> > +endif
>
> AFAIK, CONFIG_COMPAT is only defined when CONFIG_PP64 is defined, so
> could be:
>
> obj-$(CONFIG_COMPAT) += sys_ppc32.o ptrace32.o
>
> And could be grouped with the above signal_32.o
>
Looks better.
>
> > obj-$(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 2ec825a85f5b..a2dbf216f607 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
>
> Can we avoid this ifdef ?
AFAICT it creates reference to non-existent table otherwise.
>
> >
> > /* 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..ffd045e9fb57 100644
> > --- a/arch/powerpc/kernel/signal.c
> > +++ b/arch/powerpc/kernel/signal.c
> > @@ -277,14 +277,15 @@ static void do_signal(struct task_struct *tsk)
> >
> > rseq_signal_deliver(, tsk->thread.regs);
> >
> > +#if !defined(CONFIG_PPC64) || defined(CONFIG_COMPAT)
> > if (is32) {
> > if (ksig.ka.sa.sa_flags & SA_SIGINFO)
> > ret = handle_rt_signal32(, oldset, tsk);
> > else
> > ret = handle_signal32(, oldset, tsk);
> >
Re: [PATCH v2 3/4] powerpc/64: make buildable without CONFIG_COMPAT
Le 28/08/2019 à 12:30, Michal Suchanek a écrit :
There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.
As far as possible, avoid opting things out with ifdefs. Ref
https://www.kernel.org/doc/html/latest/process/coding-style.html#conditional-compilation
See comment below.
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
---
arch/powerpc/include/asm/syscall.h | 2 ++
arch/powerpc/kernel/Makefile | 15 ---
arch/powerpc/kernel/entry_64.S | 2 ++
arch/powerpc/kernel/signal.c | 5 +++--
arch/powerpc/kernel/syscall_64.c | 5 +++--
arch/powerpc/kernel/vdso.c | 4 +++-
arch/powerpc/perf/callchain.c | 14 ++
7 files changed, 35 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/include/asm/syscall.h
b/arch/powerpc/include/asm/syscall.h
index 38d62acfdce7..3ed3b75541a1 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -16,7 +16,9 @@
/* ftrace syscalls requires exporting the sys_call_table */
extern const unsigned long sys_call_table[];
+#ifdef CONFIG_COMPAT
extern const unsigned long compat_sys_call_table[];
+#endif
Leaving the declaration should be harmless.
static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
{
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 1d646a94d96c..b0db365b83d8 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -44,16 +44,25 @@ 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 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 \
+ifndef CONFIG_PPC64
+obj-y += signal_32.o
+else
+ifdef CONFIG_COMPAT
+obj-y += signal_32.o
+endif
+endif
+obj-$(CONFIG_PPC64)+= setup_64.o signal_64.o \
paca.o nvram_64.o firmware.o \
syscall_64.o
That's still a bit messy. You could have:
obj-y = +=signal_$(BITS).o
obj-$(CONFIG_COMPAT) += signal_32.o
+ifdef CONFIG_COMPAT
+obj-$(CONFIG_PPC64)+= sys_ppc32.o ptrace32.o
+endif
AFAIK, CONFIG_COMPAT is only defined when CONFIG_PP64 is defined, so
could be:
obj-$(CONFIG_COMPAT)+= sys_ppc32.o ptrace32.o
And could be grouped with the above signal_32.o
obj-$(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 2ec825a85f5b..a2dbf216f607 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
Can we avoid this ifdef ?
/* 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..ffd045e9fb57 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -277,14 +277,15 @@ static void do_signal(struct task_struct *tsk)
rseq_signal_deliver(, tsk->thread.regs);
+#if !defined(CONFIG_PPC64) || defined(CONFIG_COMPAT)
if (is32) {
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
ret = handle_rt_signal32(, oldset, tsk);
else
ret = handle_signal32(, oldset, tsk);
- } else {
+ } else
" if only one branch of a conditional statement is a single statement
[...] use braces in both branches"
Ref
https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces
+#endif /* 32bit */
Having an #ifdef in a middle of a if/else is gross.
Check what are the possible values for is32. It will be always true
which CONFIG_PPC32.
If you can make sure it is always false without CONFIG_COMPAT, you are
done. If not, then combine the if(is32) with something involving
IS_ENABLED(CONFIG_COMPAT).
ret = handle_rt_signal64(,
[PATCH v2 3/4] 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
---
arch/powerpc/include/asm/syscall.h | 2 ++
arch/powerpc/kernel/Makefile | 15 ---
arch/powerpc/kernel/entry_64.S | 2 ++
arch/powerpc/kernel/signal.c | 5 +++--
arch/powerpc/kernel/syscall_64.c | 5 +++--
arch/powerpc/kernel/vdso.c | 4 +++-
arch/powerpc/perf/callchain.c | 14 ++
7 files changed, 35 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/include/asm/syscall.h
b/arch/powerpc/include/asm/syscall.h
index 38d62acfdce7..3ed3b75541a1 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -16,7 +16,9 @@
/* ftrace syscalls requires exporting the sys_call_table */
extern const unsigned long sys_call_table[];
+#ifdef CONFIG_COMPAT
extern const unsigned long compat_sys_call_table[];
+#endif
static inline int syscall_get_nr(struct task_struct *task, struct pt_regs
*regs)
{
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 1d646a94d96c..b0db365b83d8 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -44,16 +44,25 @@ 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 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 \
+ifndef CONFIG_PPC64
+obj-y += signal_32.o
+else
+ifdef CONFIG_COMPAT
+obj-y += signal_32.o
+endif
+endif
+obj-$(CONFIG_PPC64)+= setup_64.o signal_64.o \
paca.o nvram_64.o firmware.o \
syscall_64.o
+ifdef CONFIG_COMPAT
+obj-$(CONFIG_PPC64)+= sys_ppc32.o ptrace32.o
+endif
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 2ec825a85f5b..a2dbf216f607 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..ffd045e9fb57 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -277,14 +277,15 @@ static void do_signal(struct task_struct *tsk)
rseq_signal_deliver(, tsk->thread.regs);
+#if !defined(CONFIG_PPC64) || defined(CONFIG_COMPAT)
if (is32) {
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
ret = handle_rt_signal32(, oldset, tsk);
else
ret = handle_signal32(, oldset, tsk);
- } else {
+ } else
+#endif /* 32bit */
ret = handle_rt_signal64(, oldset, tsk);
- }
tsk->thread.regs->trap = 0;
signal_setup_done(ret, , test_thread_flag(TIF_SINGLESTEP));
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 98ed970796d5..3f48262b512d 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -100,6 +100,7 @@ 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();
+#ifdef CONFIG_COMPAT
if (unlikely(ti_flags & _TIF_32BIT)) {
f = (void *)compat_sys_call_table[r0];
@@ -110,9 +111,9 @@ long system_call_exception(long r3, long r4, long r5, long
r6, long r7, long r8,
r7 &= 0xULL;
r8 &= 0xULL;
- } else {
+ } else
+#endif /* CONFIG_COMPAT */
f = (void *)sys_call_table[r0];
- }
return f(r3, r4, r5, r6, r7, r8);
}
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index d60598113a9f..a991b5d69010 100644
--- a/arch/powerpc/kernel/vdso.c
