Re: [PATCH v7 4/6] powerpc/64: make buildable without CONFIG_COMPAT
From: Christophe Leroy
Date: Sat Aug 31 2019 - 02:43:33 EST
Le 30/08/2019 Ã 23:03, Michal Suchanek a ÃcritÂ:
There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.
Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
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
---
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 | 31 +++++++++++++-------------
7 files changed, 27 insertions(+), 31 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 b7cdcce20280..9b8dc822f531 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"
#endif
#include <asm/pte-walk.h>
@@ -268,16 +268,6 @@ static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
}
}
-static inline int current_is_64bit(void)
-{
- /*
- * We can't use test_thread_flag() here because we may be on an
- * interrupt stack, and the thread flags don't get copied over
- * from the thread_info on the main stack to the interrupt stack.
- */
- return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
-}
-
#else /* CONFIG_PPC64 */
static int read_user_stack_slow(void __user *ptr, void *buf, int nb)
{
@@ -314,11 +304,6 @@ static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry
{
}
-static inline int current_is_64bit(void)
-{
- return 0;
-}
-
static inline int valid_user_sp(unsigned long sp, int is_64)
{
if (!sp || (sp & 7) || sp > TASK_SIZE - 32)
@@ -334,6 +319,7 @@ 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
*/
@@ -475,6 +461,19 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
sp = next_sp;
}
}
+#endif /* 32bit */
+
+static inline int current_is_64bit(void)
+{
+ if (!IS_ENABLED(CONFIG_COMPAT))
+ return IS_ENABLED(CONFIG_PPC64);
+ /*
+ * We can't use test_thread_flag() here because we may be on an
+ * interrupt stack, and the thread flags don't get copied over
+ * from the thread_info on the main stack to the interrupt stack.
+ */
+ return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
+}
void
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)