2019-09-13 13:01:02

by Michal Suchánek

[permalink] [raw]
Subject: [PATCH v9 4/8] powerpc/perf: consolidate valid_user_sp

Merge the 32bit and 64bit version.

Halve the check constants on 32bit.

Use STACK_TOP since it is defined.

This removes a page from the valid 32bit area on 64bit:
#define TASK_SIZE_USER32 (0x0000000100000000UL - (1 * PAGE_SIZE))
#define STACK_TOP_USER32 TASK_SIZE_USER32

Signed-off-by: Michal Suchanek <[email protected]>
---
v8: new patch
---
arch/powerpc/perf/callchain.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index d86bdbffda9e..7863ee0a0e69 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -102,6 +102,20 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
}
}

+static inline int valid_user_sp(unsigned long sp, int is_64)
+{
+ unsigned long stack_top;
+
+ if (IS_ENABLED(CONFIG_PPC32))
+ stack_top = STACK_TOP;
+ else /* STACK_TOP uses is_32bit_task() but we want is_64 */
+ stack_top = is_64 ? STACK_TOP_USER64 : STACK_TOP_USER32;
+
+ if (!sp || (sp & (is_64 ? 7 : 3)) || sp > stack_top - (is_64 ? 32 : 16))
+ return 0;
+ return 1;
+}
+
#ifdef CONFIG_PPC64
/*
* On 64-bit we don't want to invoke hash_page on user addresses from
@@ -165,13 +179,6 @@ static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret)
return read_user_stack_slow(ptr, ret, 8);
}

-static inline int valid_user_sp(unsigned long sp, int is_64)
-{
- if (!sp || (sp & 7) || sp > (is_64 ? TASK_SIZE : 0x100000000UL) - 32)
- return 0;
- return 1;
-}
-
/*
* 64-bit user processes use the same stack frame for RT and non-RT signals.
*/
@@ -294,13 +301,6 @@ 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)
- return 0;
- return 1;
-}
-
#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE
#define sigcontext32 sigcontext
#define mcontext32 mcontext
--
2.23.0