On Wed, 28 Aug 2019 14:49:16 +0200 Christophe Leroy <christophe.leroy@xxxxxx> 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 <msuchanek@xxxxxxx> > > --- > > 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(&ksig, tsk->thread.regs); > > > > +#if !defined(CONFIG_PPC64) || defined(CONFIG_COMPAT) > > if (is32) { > > if (ksig.ka.sa.sa_flags & SA_SIGINFO) > > ret = handle_rt_signal32(&ksig, oldset, tsk); > > else > > ret = handle_signal32(&ksig, 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). The value of is32 is not a problem. References to non-existent functions could be. ... > > diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c > > index c84bbd4298a0..b3dacc8bc98d 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" /srv/kernel/arch/powerpc/perf/../kernel/ppc32.h:50:2: error: unknown type name ‘compat_stack_t’ When required declarations are ifdefed in compat.h > > > > static inline int valid_user_sp(unsigned long sp, int is_64) > > { > > @@ -341,6 +343,7 @@ static inline int valid_user_sp(unsigned long sp, int is_64) > > > > #endif /* CONFIG_PPC64 */ > > > > +#if !defined(CONFIG_PPC64) || defined(CONFIG_COMPAT) > > You don't need to opt that out. You need to opt out here: /srv/kernel/arch/powerpc/perf/callchain.c:349:22: error: field ‘sctx’ has incomplete type struct sigcontext32 sctx; /srv/kernel/arch/powerpc/perf/callchain.c:359:2: error: unknown type name ‘compat_siginfo_t’ compat_siginfo_t info; ... > > > /* > > * Layout for non-RT signal frames > > */ > > @@ -482,12 +485,15 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, > > sp = next_sp; > > } > > } > > +#endif /* 32bit */ > > > > void > > perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) > > { > > - if (current_is_64bit()) > > - perf_callchain_user_64(entry, regs); > > - else > > +#if !defined(CONFIG_PPC64) || defined(CONFIG_COMPAT) > > + if (!current_is_64bit()) > > perf_callchain_user_32(entry, regs); > > + else > > +#endif > > + perf_callchain_user_64(entry, regs); > > Please rewrite using IS_ENABLED() instead of #ifdefs. And ifdef here. The ifdefs could be potentially reduced in some places, though. Thanks Michal
