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.
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(&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).
ret = handle_rt_signal64(&ksig, oldset, tsk);
- }
tsk->thread.regs->trap = 0;
signal_setup_done(ret, &ksig, 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];
Don't opt out compat_sys_call_table[] declaration in .h file, and use:
if (IS_ENABLED(CONFIG_COMPAT) && unlikely(ti_flags & _TIF_32BIT)) {
@@ -110,9 +111,9 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
r7 &= 0x00000000ffffffffULL;
r8 &= 0x00000000ffffffffULL;
- } else {
+ } else
+#endif /* CONFIG_COMPAT */
Same comment above braces and #ifdefs in the middle of an if/else
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
+++ b/arch/powerpc/kernel/vdso.c
@@ -667,7 +667,7 @@ static void __init vdso_setup_syscall_map(void)
{
unsigned int i;
extern unsigned long *sys_call_table;
-#ifdef CONFIG_PPC64
+#ifdef CONFIG_COMPAT
It should be possible to get rid of that #ifdef completely.
extern unsigned long *compat_sys_call_table;
#endif
extern unsigned long sys_ni_syscall;
@@ -678,9 +678,11 @@ 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);
+#ifdef CONFIG_COMPAT
Use if (IS_ENABLED(CONFIG_COMPAT && compat_sys_call_table[i] !=
sys_ni_syscall)
if (compat_sys_call_table[i] != sys_ni_syscall)
vdso_data->syscall_map_32[i >> 5] |=
0x80000000UL >> (i & 0x1f);
+#endif /* CONFIG_COMPAT */
#else /* CONFIG_PPC64 */
if (sys_call_table[i] != sys_ni_syscall)
vdso_data->syscall_map_32[i >> 5] |=
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"
#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);
}
+#ifdef CONFIG_COMPAT
Unneeded #ifdef
static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
{
if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
@@ -180,6 +181,7 @@ static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
return read_user_stack_slow(ptr, ret, 4);
}
+#endif
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.
/*
* 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.
Christophe
