Re: [PATCH 31/33] powerpc/64: make buildable without CONFIG_COMPAT
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2019-11-13 03:02:03
Also in:
lkml
Michal Suchanek's on November 13, 2019 2:52 am:
There are numerous references to 32bit functions in generic and 64bit code so ifdef them out. Signed-off-by: Michal Suchanek <redacted>
For the most part these seem okay to me.
quoted hunk ↗ jump to hunk
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 45f1d5e54671..35874119b398 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile@@ -44,16 +44,16 @@ 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.odiff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 00173cc904ef..c339a984958f 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 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
This is just a clean up I guess.
quoted hunk ↗ jump to hunk
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c index d00cfc4a39a9..319ebd4f494d 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; if (IS_ENABLED(CONFIG_PPC_BOOK3S))@@ -64,8 +63,7 @@ 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@@ -81,7 +79,7 @@ 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;
I guess this is okay, I did want to be careful about where ti_flags was loaded exactly, but I think DOTRACE and 32BIT are not volatile. Is it possible to define _TIF_32BIT to zero for 64-bit !compat case and have the original branch eliminated, or does that cause other problems? Thanks, Nick