Add support for port I/O tracing on x86. Memory mapped I/O tracing is available on x86 via CONFIG_MMIOTRACE but that relies on page faults so it doesn't work with port I/O. This feature uses tracepoints in a similar manner as CONFIG_TRACE_MMIO_ACCESS. Signed-off-by: Dan Raymond <raymod2@xxxxxxxxx> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- V1 -> V2: - create header file for prototypes to silence new compiler warning - reduce CPU overhead to 2 instructions (no branching) when tracing disabled - fix imprecise IP logging by retrieving the IP off the stack instead of using compile time labels V2 -> V3: - restore missing semicolon V3 -> V4: - make GPL licenses consistent - change pointer arguments from (long) to (void *) - eliminate include guard checks and use -DDISABLE_TRACEPOINTS instead to disable tracepoints in arch/x86/boot/* - fix compiler warnings due to signed/unsigned mismatch in arch_cmpxchg64() arch/x86/boot/Makefile | 1 + arch/x86/boot/compressed/Makefile | 1 + arch/x86/include/asm/cmpxchg_32.h | 13 ++++---- arch/x86/include/asm/shared/io.h | 9 ++++++ arch/x86/lib/Makefile | 1 + arch/x86/lib/trace_portio.c | 21 +++++++++++++ include/linux/trace_portio.h | 6 ++++ include/linux/tracepoint-defs.h | 2 +- include/trace/events/portio.h | 49 +++++++++++++++++++++++++++++++ 9 files changed, 97 insertions(+), 6 deletions(-) create mode 100644 arch/x86/lib/trace_portio.c create mode 100644 include/linux/trace_portio.h create mode 100644 include/trace/events/portio.h diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index ffec8bb01ba8..6cec531be03b 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -70,6 +70,7 @@ KBUILD_CFLAGS := $(REALMODE_CFLAGS) -D_SETUP KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) KBUILD_CFLAGS += -fno-asynchronous-unwind-tables +KBUILD_CFLAGS += -DDISABLE_TRACEPOINTS GCOV_PROFILE := n UBSAN_SANITIZE := n diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 35ce1a64068b..c368bcc008eb 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -51,6 +51,7 @@ KBUILD_CFLAGS += -D__DISABLE_EXPORTS # Disable relocation relaxation in case the link is not PIE. KBUILD_CFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no) KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h +KBUILD_CFLAGS += -DDISABLE_TRACEPOINTS # sev.c indirectly inludes inat-table.h which is generated during # compilation and stored in $(objtree). Add the directory to the includes so diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index 215f5a65790f..054a2906eefd 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -37,13 +37,16 @@ static inline void set_64bit(volatile u64 *ptr, u64 value) #ifdef CONFIG_X86_CMPXCHG64 #define arch_cmpxchg64(ptr, o, n) \ - ((__typeof__(*(ptr)))__cmpxchg64((ptr), (unsigned long long)(o), \ + ((__typeof__(*(ptr)))__cmpxchg64((unsigned long long *)(ptr), \ + (unsigned long long)(o), \ (unsigned long long)(n))) -#define arch_cmpxchg64_local(ptr, o, n) \ - ((__typeof__(*(ptr)))__cmpxchg64_local((ptr), (unsigned long long)(o), \ +#define arch_cmpxchg64_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg64_local((unsigned long long *)(ptr), \ + (unsigned long long)(o), \ (unsigned long long)(n))) -#define arch_try_cmpxchg64(ptr, po, n) \ - __try_cmpxchg64((ptr), (unsigned long long *)(po), \ +#define arch_try_cmpxchg64(ptr, po, n) \ + __try_cmpxchg64((unsigned long long *)(ptr), \ + (unsigned long long *)(po), \ (unsigned long long)(n)) #endif diff --git a/arch/x86/include/asm/shared/io.h b/arch/x86/include/asm/shared/io.h index c0ef921c0586..82664956ce41 100644 --- a/arch/x86/include/asm/shared/io.h +++ b/arch/x86/include/asm/shared/io.h @@ -2,13 +2,20 @@ #ifndef _ASM_X86_SHARED_IO_H #define _ASM_X86_SHARED_IO_H +#include <linux/tracepoint-defs.h> +#include <linux/trace_portio.h> #include <linux/types.h> +DECLARE_TRACEPOINT(portio_write); +DECLARE_TRACEPOINT(portio_read); + #define BUILDIO(bwl, bw, type) \ static inline void __out##bwl(type value, u16 port) \ { \ asm volatile("out" #bwl " %" #bw "0, %w1" \ : : "a"(value), "Nd"(port)); \ + if (tracepoint_enabled(portio_write)) \ + do_trace_portio_write(value, port, #bwl[0]); \ } \ \ static inline type __in##bwl(u16 port) \ @@ -16,6 +23,8 @@ static inline type __in##bwl(u16 port) \ type value; \ asm volatile("in" #bwl " %w1, %" #bw "0" \ : "=a"(value) : "Nd"(port)); \ + if (tracepoint_enabled(portio_read)) \ + do_trace_portio_read(value, port, #bwl[0]); \ return value; \ } diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index f76747862bd2..254f223c025d 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -40,6 +40,7 @@ $(obj)/inat.o: $(obj)/inat-tables.c clean-files := inat-tables.c obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o +obj-$(CONFIG_TRACEPOINTS) += trace_portio.o lib-y := delay.o misc.o cmdline.o cpu.o lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o diff --git a/arch/x86/lib/trace_portio.c b/arch/x86/lib/trace_portio.c new file mode 100644 index 000000000000..b5f62dfd85a0 --- /dev/null +++ b/arch/x86/lib/trace_portio.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/instruction_pointer.h> +#include <linux/trace_portio.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/portio.h> + +void do_trace_portio_read(u32 value, u16 port, char width) +{ + trace_portio_read(value, port, width, (void *)_RET_IP_); +} +EXPORT_SYMBOL_GPL(do_trace_portio_read); +EXPORT_TRACEPOINT_SYMBOL_GPL(portio_read); + +void do_trace_portio_write(u32 value, u16 port, char width) +{ + trace_portio_write(value, port, width, (void *)_RET_IP_); +} +EXPORT_SYMBOL_GPL(do_trace_portio_write); +EXPORT_TRACEPOINT_SYMBOL_GPL(portio_write); diff --git a/include/linux/trace_portio.h b/include/linux/trace_portio.h new file mode 100644 index 000000000000..2324d62e6c9e --- /dev/null +++ b/include/linux/trace_portio.h @@ -0,0 +1,6 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <linux/types.h> + +extern void do_trace_portio_read(u32 value, u16 port, char width); +extern void do_trace_portio_write(u32 value, u16 port, char width); diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h index e7c2276be33e..bfe70e17b2aa 100644 --- a/include/linux/tracepoint-defs.h +++ b/include/linux/tracepoint-defs.h @@ -80,7 +80,7 @@ struct bpf_raw_event_map { #define DECLARE_TRACEPOINT(tp) \ extern struct tracepoint __tracepoint_##tp -#ifdef CONFIG_TRACEPOINTS +#if defined(CONFIG_TRACEPOINTS) && !defined(DISABLE_TRACEPOINTS) # define tracepoint_enabled(tp) \ static_key_false(&(__tracepoint_##tp).key) #else diff --git a/include/trace/events/portio.h b/include/trace/events/portio.h new file mode 100644 index 000000000000..7bac3ed197a8 --- /dev/null +++ b/include/trace/events/portio.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM portio + +#if !defined(_TRACE_PORTIO_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PORTIO_H + +#include <linux/tracepoint.h> + +DECLARE_EVENT_CLASS(portio_class, + TP_PROTO(u32 value, u16 port, char width, void *ip_addr), + + TP_ARGS(value, port, width, ip_addr), + + TP_STRUCT__entry( + __field(u32, value) + __field(u16, port) + __field(char, width) + __field(void *, ip_addr) + ), + + TP_fast_assign( + __entry->value = value; + __entry->port = port; + __entry->width = width; + __entry->ip_addr = ip_addr; + ), + + TP_printk("port=0x%04x value=0x%0*x %pS", + __entry->port, + __entry->width == 'b' ? 2 : + __entry->width == 'w' ? 4 : 8, + __entry->value, __entry->ip_addr) +); + +DEFINE_EVENT(portio_class, portio_read, + TP_PROTO(u32 value, u16 port, char width, void *ip_addr), + TP_ARGS(value, port, width, ip_addr) +); + +DEFINE_EVENT(portio_class, portio_write, + TP_PROTO(u32 value, u16 port, char width, void *ip_addr), + TP_ARGS(value, port, width, ip_addr) +); + +#endif /* _TRACE_PORTIO_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> base-commit: be8b93b5cc7d533eb8c9b0590cdac055ecafe13a -- 2.25.1