* [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value. @ 2013-07-30 1:12 Jed Davis 2013-07-30 1:12 ` [PATCH 2/2] x86: Fix copy_from_user_nmi return to match copy_from_user Jed Davis 2013-07-30 13:21 ` [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value Robert Richter 0 siblings, 2 replies; 4+ messages in thread From: Jed Davis @ 2013-07-30 1:12 UTC (permalink / raw) To: Peter Zijlstra, Paul Mackerras, Ingo Molnar, Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin, x86, linux-kernel Cc: Jed Davis All architectures except x86 use __copy_from_user_inatomic to provide arch_perf_out_copy_user; like the other copy_from routines, it returns the number of bytes not copied. perf was expecting the number of bytes that had been copied. This change corrects that, and thereby allows PERF_SAMPLE_STACK_USER to be enabled on non-x86 architectures. x86 uses copy_from_user_nmi, which deviates from the other copy_from routines by returning the number of bytes copied. (This cancels out the effect of perf being backwards; apparently this code has only ever been tested on x86.) This change therefore adds a second wrapper to re-reverse it for perf; the next patch in this series will clean it up. Signed-off-by: Jed Davis <jld@mozilla.com> --- arch/x86/include/asm/perf_event.h | 9 ++++++++- kernel/events/internal.h | 11 ++++++++++- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index 8249df4..ddae5bd 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -274,6 +274,13 @@ static inline void perf_check_microcode(void) { } static inline void amd_pmu_disable_virt(void) { } #endif -#define arch_perf_out_copy_user copy_from_user_nmi +static inline unsigned long copy_from_user_nmi_for_perf(void *to, + const void __user *from, + unsigned long n) +{ + return n - copy_from_user_nmi(to, from, n); +} + +#define arch_perf_out_copy_user copy_from_user_nmi_for_perf #endif /* _ASM_X86_PERF_EVENT_H */ diff --git a/kernel/events/internal.h b/kernel/events/internal.h index ca65997..e61b22c 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -81,6 +81,7 @@ static inline unsigned long perf_data_size(struct ring_buffer *rb) return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); } +/* The memcpy_func must return the number of bytes successfully copied. */ #define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \ static inline unsigned int \ func_name(struct perf_output_handle *handle, \ @@ -122,11 +123,19 @@ DEFINE_OUTPUT_COPY(__output_copy, memcpy_common) DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP) +/* arch_perf_out_copy_user must return the number of bytes not copied. */ #ifndef arch_perf_out_copy_user #define arch_perf_out_copy_user __copy_from_user_inatomic #endif -DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user) +static inline unsigned long perf_memcpy_from_user(void *to, + const void __user *from, + unsigned long n) +{ + return n - arch_perf_out_copy_user(to, from, n); +} + +DEFINE_OUTPUT_COPY(__output_copy_user, perf_memcpy_from_user) /* Callchain handling */ extern struct perf_callchain_entry * -- 1.8.3.2 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] x86: Fix copy_from_user_nmi return to match copy_from_user. 2013-07-30 1:12 [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value Jed Davis @ 2013-07-30 1:12 ` Jed Davis 2013-07-30 13:21 ` [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value Robert Richter 1 sibling, 0 replies; 4+ messages in thread From: Jed Davis @ 2013-07-30 1:12 UTC (permalink / raw) To: Peter Zijlstra, Paul Mackerras, Ingo Molnar, Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin, x86, Robert Richter, linux-kernel, oprofile-list Cc: Jed Davis copy_from_user returns the number of bytes not copied. This change makes copy_from_user_nmi behave the same way, instead of returning the number of bytes that were copied, to help prevent bugs caused by this surprising difference (and simplify callers, which mostly want to know if the number of uncopied bytes is nonzero). Signed-off-by: Jed Davis <jld@mozilla.com> --- arch/x86/include/asm/perf_event.h | 9 +-------- arch/x86/kernel/cpu/perf_event.c | 8 ++------ arch/x86/kernel/cpu/perf_event_intel_ds.c | 6 ++---- arch/x86/kernel/cpu/perf_event_intel_lbr.c | 4 +--- arch/x86/lib/usercopy.c | 2 +- arch/x86/oprofile/backtrace.c | 8 ++------ 6 files changed, 9 insertions(+), 28 deletions(-) diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index ddae5bd..8249df4 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -274,13 +274,6 @@ static inline void perf_check_microcode(void) { } static inline void amd_pmu_disable_virt(void) { } #endif -static inline unsigned long copy_from_user_nmi_for_perf(void *to, - const void __user *from, - unsigned long n) -{ - return n - copy_from_user_nmi(to, from, n); -} - -#define arch_perf_out_copy_user copy_from_user_nmi_for_perf +#define arch_perf_out_copy_user copy_from_user_nmi #endif /* _ASM_X86_PERF_EVENT_H */ diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index a7c7305..038c18c 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1983,12 +1983,10 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) fp = compat_ptr(ss_base + regs->bp); while (entry->nr < PERF_MAX_STACK_DEPTH) { - unsigned long bytes; frame.next_frame = 0; frame.return_address = 0; - bytes = copy_from_user_nmi(&frame, fp, sizeof(frame)); - if (bytes != sizeof(frame)) + if (copy_from_user_nmi(&frame, fp, sizeof(frame))) break; if (!valid_user_frame(fp, sizeof(frame))) @@ -2035,12 +2033,10 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) return; while (entry->nr < PERF_MAX_STACK_DEPTH) { - unsigned long bytes; frame.next_frame = NULL; frame.return_address = 0; - bytes = copy_from_user_nmi(&frame, fp, sizeof(frame)); - if (bytes != sizeof(frame)) + if (copy_from_user_nmi(&frame, fp, sizeof(frame))) 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 3065c57..5208fe1 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -729,10 +729,8 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs) old_to = to; if (!kernel_ip(ip)) { - int bytes, size = MAX_INSN_SIZE; - - bytes = copy_from_user_nmi(buf, (void __user *)to, size); - if (bytes != size) + if (copy_from_user_nmi(buf, (void __user *)to, + MAX_INSN_SIZE)) 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 d5be06a..2833514 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -449,7 +449,6 @@ static int branch_type(unsigned long from, unsigned long to, int abort) { struct insn insn; void *addr; - int bytes, size = MAX_INSN_SIZE; int ret = X86_BR_NONE; int ext, to_plm, from_plm; u8 buf[MAX_INSN_SIZE]; @@ -477,8 +476,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort) return X86_BR_NONE; /* may fail if text not present */ - bytes = copy_from_user_nmi(buf, (void __user *)from, size); - if (bytes != size) + if (copy_from_user_nmi(buf, (void __user *)from, MAX_INSN_SIZE)) return X86_BR_NONE; addr = buf; diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 4f74d94..7a13c98 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -44,6 +44,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) } while (len < n); - return len; + return n - len; } EXPORT_SYMBOL_GPL(copy_from_user_nmi); diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index d6aa6e8..e778d41 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -44,10 +44,8 @@ dump_user_backtrace_32(struct stack_frame_ia32 *head) /* Also check accessibility of one struct frame_head beyond: */ struct stack_frame_ia32 bufhead[2]; struct stack_frame_ia32 *fp; - unsigned long bytes; - bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead)); - if (bytes != sizeof(bufhead)) + if (copy_from_user_nmi(bufhead, head, sizeof(bufhead))) return NULL; fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame); @@ -90,10 +88,8 @@ static struct stack_frame *dump_user_backtrace(struct stack_frame *head) { /* Also check accessibility of one struct frame_head beyond: */ struct stack_frame bufhead[2]; - unsigned long bytes; - bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead)); - if (bytes != sizeof(bufhead)) + if (copy_from_user_nmi(bufhead, head, sizeof(bufhead))) return NULL; oprofile_add_trace(bufhead[0].return_address); -- 1.8.3.2 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value. 2013-07-30 1:12 [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value Jed Davis 2013-07-30 1:12 ` [PATCH 2/2] x86: Fix copy_from_user_nmi return to match copy_from_user Jed Davis @ 2013-07-30 13:21 ` Robert Richter 2013-08-16 23:44 ` [PATCH v2] x86, perf: Fix arch_perf_out_copy_user and copy_from_user_nmi return values Jed Davis 1 sibling, 1 reply; 4+ messages in thread From: Robert Richter @ 2013-07-30 13:21 UTC (permalink / raw) To: Jed Davis Cc: Peter Zijlstra, Paul Mackerras, Ingo Molnar, Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin, x86, linux-kernel On 29.07.13 18:12:40, Jed Davis wrote: > All architectures except x86 use __copy_from_user_inatomic to provide > arch_perf_out_copy_user; like the other copy_from routines, it returns > the number of bytes not copied. perf was expecting the number of bytes > that had been copied. This change corrects that, and thereby allows > PERF_SAMPLE_STACK_USER to be enabled on non-x86 architectures. > > x86 uses copy_from_user_nmi, which deviates from the other copy_from > routines by returning the number of bytes copied. (This cancels out > the effect of perf being backwards; apparently this code has only ever > been tested on x86.) This change therefore adds a second wrapper to > re-reverse it for perf; the next patch in this series will clean it up. > > Signed-off-by: Jed Davis <jld@mozilla.com> > --- > arch/x86/include/asm/perf_event.h | 9 ++++++++- > kernel/events/internal.h | 11 ++++++++++- > 2 files changed, 18 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h > index 8249df4..ddae5bd 100644 > --- a/arch/x86/include/asm/perf_event.h > +++ b/arch/x86/include/asm/perf_event.h > @@ -274,6 +274,13 @@ static inline void perf_check_microcode(void) { } > static inline void amd_pmu_disable_virt(void) { } > #endif > > -#define arch_perf_out_copy_user copy_from_user_nmi > +static inline unsigned long copy_from_user_nmi_for_perf(void *to, > + const void __user *from, > + unsigned long n) > +{ > + return n - copy_from_user_nmi(to, from, n); > +} > + > +#define arch_perf_out_copy_user copy_from_user_nmi_for_perf I like your change of copy_from_user_nmi() to return bytes not copied since it makes callers simpler and has the same i/f as other copy functions. Please do not introduce code that you later remove, instead merge this patch with your next. > > #endif /* _ASM_X86_PERF_EVENT_H */ > diff --git a/kernel/events/internal.h b/kernel/events/internal.h > index ca65997..e61b22c 100644 > --- a/kernel/events/internal.h > +++ b/kernel/events/internal.h > @@ -81,6 +81,7 @@ static inline unsigned long perf_data_size(struct ring_buffer *rb) > return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); > } > > +/* The memcpy_func must return the number of bytes successfully copied. */ > #define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \ > static inline unsigned int \ > func_name(struct perf_output_handle *handle, \ > @@ -122,11 +123,19 @@ DEFINE_OUTPUT_COPY(__output_copy, memcpy_common) > > DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP) > > +/* arch_perf_out_copy_user must return the number of bytes not copied. */ > #ifndef arch_perf_out_copy_user > #define arch_perf_out_copy_user __copy_from_user_inatomic > #endif > > -DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user) > +static inline unsigned long perf_memcpy_from_user(void *to, > + const void __user *from, > + unsigned long n) > +{ > + return n - arch_perf_out_copy_user(to, from, n); > +} > + > +DEFINE_OUTPUT_COPY(__output_copy_user, perf_memcpy_from_user) Better modify DEFINE_OUTPUT_COPY() to deal with bytes-not-copied as return value for memcpy_func(). Other users of DEFINE_OUTPUT_COPY() could be fixed easily. -Robert ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2] x86, perf: Fix arch_perf_out_copy_user and copy_from_user_nmi return values 2013-07-30 13:21 ` [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value Robert Richter @ 2013-08-16 23:44 ` Jed Davis 0 siblings, 0 replies; 4+ messages in thread From: Jed Davis @ 2013-08-16 23:44 UTC (permalink / raw) To: Peter Zijlstra, Paul Mackerras, Ingo Molnar, Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin, x86, Robert Richter, linux-kernel, oprofile-list Cc: Jed Davis All architectures except x86 use __copy_from_user_inatomic to provide arch_perf_out_copy_user; like the other copy_from routines, it returns the number of bytes not copied. perf was expecting the number of bytes that had been copied. This change corrects that, and thereby allows PERF_SAMPLE_STACK_USER to be enabled on non-x86 architectures. x86 uses copy_from_user_nmi, which deviates from the other copy_from routines by returning the number of bytes copied. This change therefore also reverses copy_from_user_nmi's return value, so that the perf change doesn't break user stack copies on x86, and to help prevent bugs caused by this surprising difference (and simplify callers, which mostly want to know if the number of uncopied bytes is nonzero). Signed-off-by: Jed Davis <jld@mozilla.com> --- arch/x86/kernel/cpu/perf_event.c | 8 ++------ arch/x86/kernel/cpu/perf_event_intel_ds.c | 6 ++---- arch/x86/kernel/cpu/perf_event_intel_lbr.c | 4 +--- arch/x86/lib/usercopy.c | 2 +- arch/x86/oprofile/backtrace.c | 8 ++------ kernel/events/internal.h | 9 +++++---- 6 files changed, 13 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index a7c7305..038c18c 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1983,12 +1983,10 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) fp = compat_ptr(ss_base + regs->bp); while (entry->nr < PERF_MAX_STACK_DEPTH) { - unsigned long bytes; frame.next_frame = 0; frame.return_address = 0; - bytes = copy_from_user_nmi(&frame, fp, sizeof(frame)); - if (bytes != sizeof(frame)) + if (copy_from_user_nmi(&frame, fp, sizeof(frame))) break; if (!valid_user_frame(fp, sizeof(frame))) @@ -2035,12 +2033,10 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) return; while (entry->nr < PERF_MAX_STACK_DEPTH) { - unsigned long bytes; frame.next_frame = NULL; frame.return_address = 0; - bytes = copy_from_user_nmi(&frame, fp, sizeof(frame)); - if (bytes != sizeof(frame)) + if (copy_from_user_nmi(&frame, fp, sizeof(frame))) 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 3065c57..5208fe1 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -729,10 +729,8 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs) old_to = to; if (!kernel_ip(ip)) { - int bytes, size = MAX_INSN_SIZE; - - bytes = copy_from_user_nmi(buf, (void __user *)to, size); - if (bytes != size) + if (copy_from_user_nmi(buf, (void __user *)to, + MAX_INSN_SIZE)) 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 d5be06a..2833514 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -449,7 +449,6 @@ static int branch_type(unsigned long from, unsigned long to, int abort) { struct insn insn; void *addr; - int bytes, size = MAX_INSN_SIZE; int ret = X86_BR_NONE; int ext, to_plm, from_plm; u8 buf[MAX_INSN_SIZE]; @@ -477,8 +476,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort) return X86_BR_NONE; /* may fail if text not present */ - bytes = copy_from_user_nmi(buf, (void __user *)from, size); - if (bytes != size) + if (copy_from_user_nmi(buf, (void __user *)from, MAX_INSN_SIZE)) return X86_BR_NONE; addr = buf; diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 4f74d94..7a13c98 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -44,6 +44,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) } while (len < n); - return len; + return n - len; } EXPORT_SYMBOL_GPL(copy_from_user_nmi); diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index d6aa6e8..e778d41 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -44,10 +44,8 @@ dump_user_backtrace_32(struct stack_frame_ia32 *head) /* Also check accessibility of one struct frame_head beyond: */ struct stack_frame_ia32 bufhead[2]; struct stack_frame_ia32 *fp; - unsigned long bytes; - bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead)); - if (bytes != sizeof(bufhead)) + if (copy_from_user_nmi(bufhead, head, sizeof(bufhead))) return NULL; fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame); @@ -90,10 +88,8 @@ static struct stack_frame *dump_user_backtrace(struct stack_frame *head) { /* Also check accessibility of one struct frame_head beyond: */ struct stack_frame bufhead[2]; - unsigned long bytes; - bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead)); - if (bytes != sizeof(bufhead)) + if (copy_from_user_nmi(bufhead, head, sizeof(bufhead))) return NULL; oprofile_add_trace(bufhead[0].return_address); diff --git a/kernel/events/internal.h b/kernel/events/internal.h index ca65997..f77120f 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -81,7 +81,8 @@ static inline unsigned long perf_data_size(struct ring_buffer *rb) return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); } -#define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \ +/* func_name and copy_func return the number of bytes not copied */ +#define DEFINE_OUTPUT_COPY(func_name, copy_func) \ static inline unsigned int \ func_name(struct perf_output_handle *handle, \ const void *buf, unsigned int len) \ @@ -91,7 +92,7 @@ func_name(struct perf_output_handle *handle, \ do { \ size = min_t(unsigned long, handle->size, len); \ \ - written = memcpy_func(handle->addr, buf, size); \ + written = size - copy_func(handle->addr, buf, size); \ \ len -= written; \ handle->addr += written; \ @@ -113,12 +114,12 @@ func_name(struct perf_output_handle *handle, \ static inline int memcpy_common(void *dst, const void *src, size_t n) { memcpy(dst, src, n); - return n; + return 0; } DEFINE_OUTPUT_COPY(__output_copy, memcpy_common) -#define MEMCPY_SKIP(dst, src, n) (n) +#define MEMCPY_SKIP(dst, src, n) (0) DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP) -- 1.8.3.2 ^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-08-16 23:56 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-07-30 1:12 [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value Jed Davis 2013-07-30 1:12 ` [PATCH 2/2] x86: Fix copy_from_user_nmi return to match copy_from_user Jed Davis 2013-07-30 13:21 ` [PATCH 1/2] perf: Fix handling of arch_perf_out_copy_user return value Robert Richter 2013-08-16 23:44 ` [PATCH v2] x86, perf: Fix arch_perf_out_copy_user and copy_from_user_nmi return values Jed Davis
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