Le 29/08/2019 à 12:23, 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 <msucha...@suse.de>
---
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
---
  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             |  5 ++---
  arch/powerpc/perf/callchain.c          | 14 ++++++++++----
  7 files changed, 22 insertions(+), 19 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 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..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 98ed970796d5..0d5cbbe54cf1 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -38,7 +38,6 @@ 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));
@@ -83,8 +82,7 @@ long system_call_exception(long r3, long r4, long r5, long 
r6, long r7, long r8,
         */
        regs->softe = IRQS_ENABLED;
- 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
@@ -100,7 +98,7 @@ 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..6d4a077f74d6 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -667,9 +667,7 @@ static void __init vdso_setup_syscall_map(void)
  {
        unsigned int i;
        extern unsigned long *sys_call_table;
-#ifdef CONFIG_PPC64
        extern unsigned long *compat_sys_call_table;
-#endif
        extern unsigned long sys_ni_syscall;
@@ -678,7 +676,8 @@ 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 c84bbd4298a0..aef8c750d242 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

Is this ifdef needed at all ? Is it a problem to include it all the time ?

  #include "../kernel/ppc32.h"
  #endif
  #include <asm/pte-walk.h>
@@ -165,6 +165,7 @@ static int read_user_stack_64(unsigned long __user *ptr, 
unsigned long *ret)
        return read_user_stack_slow(ptr, ret, 8);
  }
+__maybe_unused

I don't like that too much. I see this function is almost identical between PPC64 and PPC32. It should be possible to have only one, using IS_ENABLED(CONFIG_PPC64) inside it to call read_user_stack_slow(). An define a dummy read_user_stack_slow() for PPC32 as already done for perf_callchain_user_64().

  static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
  {
        if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
@@ -341,6 +342,7 @@ static inline int valid_user_sp(unsigned long sp, int is_64)
#endif /* CONFIG_PPC64 */ +#if defined(CONFIG_PPC32) || defined(CONFIG_COMPAT)
  /*
   * Layout for non-RT signal frames
   */
@@ -482,12 +484,16 @@ 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_PPC32) || defined(CONFIG_COMPAT)
+       if (!current_is_64bit()) {
                perf_callchain_user_32(entry, regs);
+               return;
+       }
+#endif
+       perf_callchain_user_64(entry, regs);
  }


Instead of that it could just be:

        if (current_is_64bit())
                perf_callchain_user_64(entry, regs);
        else
                perf_callchain_user_32(entry, regs);


By adding a dummy perf_callchain_user_32() when needed as already done for perf_callchain_user_64() And by making sure current_is_64bit() returns IS_ENABLED(CONFIG_PPC64) when CONFIG_COMPAT is not set, on the same principle as you did for is_32bit_task()

And maybe you could think about spliting callchain.c out in a callchain_32.c and a callchain_64.c that gets selected by the Makefiles based on the same principle as you did for ptrace_32.c etc...

Christophe

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