2020-03-20 10:21:15

by Michal Suchánek

[permalink] [raw]
Subject: [PATCH v12 5/8] powerpc/64: make buildable without CONFIG_COMPAT

There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.

Signed-off-by: Michal Suchanek <[email protected]>
---
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
v8:
- fix build again - too trigger-happy with stub removal
- remove a vdso.c hunk that causes warning according to kbuild test robot
v9:
- removed current_is_64bit in previous patch
v10:
- rebase on top of 70ed86f4de5bd
---
arch/powerpc/include/asm/thread_info.h | 4 ++--
arch/powerpc/kernel/Makefile | 6 +++---
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 | 3 ++-
arch/powerpc/perf/callchain.c | 8 +++++++-
7 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index a2270749b282..ca6c97025704 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -162,10 +162,10 @@ 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 5700231a8988..98a1c143b613 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -42,16 +42,16 @@ 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.o
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 4c0d0400e93d..fe1421e08f09 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 4b0152108f61..a264989626fd 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 87d95b455b83..2dcbfe38f5ac 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -24,7 +24,6 @@ notrace 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_IRQ_SOFT_MASK_DEBUG))
@@ -68,8 +67,7 @@ notrace long system_call_exception(long r3, long r4, long r5,

local_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
@@ -94,7 +92,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
/* 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 b9a108411c0d..77da3b7d304d 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -656,7 +656,8 @@ 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 001d0473a61f..b5afd0bec4f8 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>
@@ -284,6 +284,7 @@ static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry

#endif /* CONFIG_PPC64 */

+#if defined(CONFIG_PPC32) || defined(CONFIG_COMPAT)
/*
* On 32-bit we just access the address and let hash_page create a
* HPTE if necessary, so there is no need to fall back to reading
@@ -447,6 +448,11 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
sp = next_sp;
}
}
+#else /* 32bit */
+static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
+{}
+#endif /* 32bit */

void
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
--
2.23.0


2020-04-07 05:51:26

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH v12 5/8] powerpc/64: make buildable without CONFIG_COMPAT



Le 20/03/2020 à 11:20, 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 <[email protected]>
> ---
> 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
> v8:
> - fix build again - too trigger-happy with stub removal
> - remove a vdso.c hunk that causes warning according to kbuild test robot
> v9:
> - removed current_is_64bit in previous patch
> v10:
> - rebase on top of 70ed86f4de5bd
> ---
> arch/powerpc/include/asm/thread_info.h | 4 ++--
> arch/powerpc/kernel/Makefile | 6 +++---
> 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 | 3 ++-
> arch/powerpc/perf/callchain.c | 8 +++++++-
> 7 files changed, 19 insertions(+), 13 deletions(-)
>

[...]

> diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
> index 87d95b455b83..2dcbfe38f5ac 100644
> --- a/arch/powerpc/kernel/syscall_64.c
> +++ b/arch/powerpc/kernel/syscall_64.c
> @@ -24,7 +24,6 @@ notrace 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_IRQ_SOFT_MASK_DEBUG))
> @@ -68,8 +67,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
>
> local_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
> @@ -94,7 +92,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
> /* May be faster to do array_index_nospec? */
> barrier_nospec();
>
> - if (unlikely(ti_flags & _TIF_32BIT)) {
> + if (unlikely(is_32bit_task())) {

is_compat() should be used here instead, because we dont want to use
compat_sys_call_table() on PPC32.

> f = (void *)compat_sys_call_table[r0];
>
> r3 &= 0x00000000ffffffffULL;

Christophe

2020-04-07 09:59:54

by Michal Suchánek

[permalink] [raw]
Subject: Re: [PATCH v12 5/8] powerpc/64: make buildable without CONFIG_COMPAT

On Tue, Apr 07, 2020 at 07:50:30AM +0200, Christophe Leroy wrote:
>
>
> Le 20/03/2020 ? 11:20, Michal Suchanek a ?crit?:
> > There are numerous references to 32bit functions in generic and 64bit
> > code so ifdef them out.
> >
> > Signed-off-by: Michal Suchanek <[email protected]>
> > ---
> > 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
> > v8:
> > - fix build again - too trigger-happy with stub removal
> > - remove a vdso.c hunk that causes warning according to kbuild test robot
> > v9:
> > - removed current_is_64bit in previous patch
> > v10:
> > - rebase on top of 70ed86f4de5bd
> > ---
> > arch/powerpc/include/asm/thread_info.h | 4 ++--
> > arch/powerpc/kernel/Makefile | 6 +++---
> > 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 | 3 ++-
> > arch/powerpc/perf/callchain.c | 8 +++++++-
> > 7 files changed, 19 insertions(+), 13 deletions(-)
> >
>
> [...]
>
> > diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
> > index 87d95b455b83..2dcbfe38f5ac 100644
> > --- a/arch/powerpc/kernel/syscall_64.c
> > +++ b/arch/powerpc/kernel/syscall_64.c
> > @@ -24,7 +24,6 @@ notrace 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_IRQ_SOFT_MASK_DEBUG))
> > @@ -68,8 +67,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
> > local_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
> > @@ -94,7 +92,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
> > /* May be faster to do array_index_nospec? */
> > barrier_nospec();
> > - if (unlikely(ti_flags & _TIF_32BIT)) {
> > + if (unlikely(is_32bit_task())) {
>
> is_compat() should be used here instead, because we dont want to use
is_compat_task()
> compat_sys_call_table() on PPC32.
>
> > f = (void *)compat_sys_call_table[r0];
> > r3 &= 0x00000000ffffffffULL;
>
That only applies once you use this for 32bit as well. Right now it's
64bit only so the two are the same.

Thanks

Michal