On 08/29/2019 10:28 PM, Michal Suchanek wrote:
> Building callchain.c with !COMPAT proved quite ugly with all the
> defines. Splitting out the 32bit and 64bit parts looks better.
>
> Also rewrite current_is_64bit as common function. No other code change
> intended.
Nice result.
Could look even better by merging both read_user_stack_32(), see below.
Also a possible cosmetic change to Makefile.
---
arch/powerpc/perf/Makefile | 7 ++---
arch/powerpc/perf/callchain_32.c | 65 ++++++++++++++++------------------------
2 files changed, 29 insertions(+), 43 deletions(-)
diff --git a/arch/powerpc/perf/Makefile b/arch/powerpc/perf/Makefile
index e9f3202251d0..53d614e98537 100644
--- a/arch/powerpc/perf/Makefile
+++ b/arch/powerpc/perf/Makefile
@@ -1,9 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_PERF_EVENTS) += callchain.o perf_regs.o
-ifdef CONFIG_PERF_EVENTS
-obj-y += callchain_$(BITS).o
-obj-$(CONFIG_COMPAT) += callchain_32.o
+obj-$(CONFIG_PERF_EVENTS) += callchain.o callchain_$(BITS).o perf_regs.o
+ifdef CONFIG_COMPAT
+obj-$(CONFIG_PERF_EVENTS) += callchain_32.o
endif
obj-$(CONFIG_PPC_PERF_CTRS) += core-book3s.o bhrb.o
diff --git a/arch/powerpc/perf/callchain_32.c b/arch/powerpc/perf/callchain_32.c
index 0bd4484eddaa..17c43ae03084 100644
--- a/arch/powerpc/perf/callchain_32.c
+++ b/arch/powerpc/perf/callchain_32.c
@@ -15,50 +15,13 @@
#include <asm/sigcontext.h>
#include <asm/ucontext.h>
#include <asm/vdso.h>
-#ifdef CONFIG_PPC64
-#include "../kernel/ppc32.h"
-#endif
#include <asm/pte-walk.h>
#include "callchain.h"
#ifdef CONFIG_PPC64
-static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
-{
- if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
- ((unsigned long)ptr & 3))
- return -EFAULT;
-
- pagefault_disable();
- if (!__get_user_inatomic(*ret, ptr)) {
- pagefault_enable();
- return 0;
- }
- pagefault_enable();
-
- return read_user_stack_slow(ptr, ret, 4);
-}
-#else /* CONFIG_PPC64 */
-/*
- * 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
- * the page tables. Since this is called at interrupt level,
- * do_page_fault() won't treat a DSI as a page fault.
- */
-static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
-{
- int rc;
-
- if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
- ((unsigned long)ptr & 3))
- return -EFAULT;
-
- pagefault_disable();
- rc = __get_user_inatomic(*ret, ptr);
- pagefault_enable();
-
- return rc;
-}
+#include "../kernel/ppc32.h"
+#else
#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE
#define sigcontext32 sigcontext
@@ -95,6 +58,30 @@ struct rt_signal_frame_32 {
int abigap[56];
};
+/*
+ * 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
+ * the page tables. Since this is called at interrupt level,
+ * do_page_fault() won't treat a DSI as a page fault.
+ */
+static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
+{
+ int rc;
+
+ if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
+ ((unsigned long)ptr & 3))
+ return -EFAULT;
+
+ pagefault_disable();
+ rc = __get_user_inatomic(*ret, ptr);
+ pagefault_enable();
+
+ if (IS_ENABLED(CONFIG_PPC32) || !rc)
+ return rc;
+
+ return read_user_stack_slow(ptr, ret, 4);
+}
+
static int is_sigreturn_32_address(unsigned int nip, unsigned int fp)
{
if (nip == fp + offsetof(struct signal_frame_32, mctx.mc_pad))
--
2.13.3
