[tip:perf/core] perf: Fix arch_perf_out_copy_user default
From: tip-bot for Peter Zijlstra
Date: Wed Nov 06 2013 - 08:20:00 EST
Commit-ID: 0a196848ca365ec582c6d86659be456be6d4ed96
Gitweb: http://git.kernel.org/tip/0a196848ca365ec582c6d86659be456be6d4ed96
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Wed, 30 Oct 2013 21:16:22 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 6 Nov 2013 12:34:25 +0100
perf: Fix arch_perf_out_copy_user default
The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.
Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.
Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Acked-by: will.deacon@xxxxxxx
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20131030201622.GR16117@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event.c | 4 ++--
arch/x86/kernel/cpu/perf_event_intel_ds.c | 2 +-
arch/x86/kernel/cpu/perf_event_intel_lbr.c | 2 +-
arch/x86/lib/usercopy.c | 2 +-
arch/x86/oprofile/backtrace.c | 4 ++--
kernel/events/internal.h | 35 ++++++++++++++++++++++--------
6 files changed, 33 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 8a87a32..8e13293 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1989,7 +1989,7 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
frame.return_address = 0;
bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
- if (bytes != sizeof(frame))
+ if (bytes != 0)
break;
if (!valid_user_frame(fp, sizeof(frame)))
@@ -2041,7 +2041,7 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
frame.return_address = 0;
bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
- if (bytes != sizeof(frame))
+ if (bytes != 0)
break;
if (!valid_user_frame(fp, sizeof(frame)))
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index c1760ff..ae96cfa 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -789,7 +789,7 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
size = ip - to; /* Must fit our buffer, see above */
bytes = copy_from_user_nmi(buf, (void __user *)to, size);
- if (bytes != size)
+ if (bytes != 0)
return 0;
kaddr = buf;
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index 90ee6c1..d82d155 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -491,7 +491,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
/* may fail if text not present */
bytes = copy_from_user_nmi(buf, (void __user *)from, size);
- if (bytes != size)
+ if (bytes != 0)
return X86_BR_NONE;
addr = buf;
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index 5465b86..ddf9ecb 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -31,6 +31,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
ret = __copy_from_user_inatomic(to, from, n);
pagefault_enable();
- return n - ret;
+ return ret;
}
EXPORT_SYMBOL_GPL(copy_from_user_nmi);
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index d6aa6e8..5d04be5 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -47,7 +47,7 @@ dump_user_backtrace_32(struct stack_frame_ia32 *head)
unsigned long bytes;
bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
- if (bytes != sizeof(bufhead))
+ if (bytes != 0)
return NULL;
fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
@@ -93,7 +93,7 @@ static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
unsigned long bytes;
bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
- if (bytes != sizeof(bufhead))
+ if (bytes != 0)
return NULL;
oprofile_add_trace(bufhead[0].return_address);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index ca65997..569b2187 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -82,16 +82,16 @@ static inline unsigned long perf_data_size(struct ring_buffer *rb)
}
#define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \
-static inline unsigned int \
+static inline unsigned long \
func_name(struct perf_output_handle *handle, \
- const void *buf, unsigned int len) \
+ const void *buf, unsigned long len) \
{ \
unsigned long size, written; \
\
do { \
- size = min_t(unsigned long, handle->size, len); \
- \
+ size = min(handle->size, len); \
written = memcpy_func(handle->addr, buf, size); \
+ written = size - written; \
\
len -= written; \
handle->addr += written; \
@@ -110,20 +110,37 @@ func_name(struct perf_output_handle *handle, \
return len; \
}
-static inline int memcpy_common(void *dst, const void *src, size_t n)
+static inline unsigned long
+memcpy_common(void *dst, const void *src, unsigned long n)
{
memcpy(dst, src, n);
- return n;
+ return 0;
}
DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
-#define MEMCPY_SKIP(dst, src, n) (n)
+static inline unsigned long
+memcpy_skip(void *dst, const void *src, unsigned long n)
+{
+ return 0;
+}
-DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP)
+DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
#ifndef arch_perf_out_copy_user
-#define arch_perf_out_copy_user __copy_from_user_inatomic
+#define arch_perf_out_copy_user arch_perf_out_copy_user
+
+static inline unsigned long
+arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
+{
+ unsigned long ret;
+
+ pagefault_disable();
+ ret = __copy_from_user_inatomic(dst, src, n);
+ pagefault_enable();
+
+ return ret;
+}
#endif
DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
--
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