bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type

Commit 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT
program type") introduced the bpf_perf_event_data structure which
exports the pt_regs structure.  This is OK for multiple architectures
but fail for s390 and arm64 which do not export pt_regs.  Programs
using them, for example, the bpf selftest fail to compile on these
architectures.

For s390, exporting the pt_regs is not an option because s390 wants
to allow changes to it.  For arm64, there is a user_pt_regs structure
that covers parts of the pt_regs structure for use by user space.

To solve the broken uapi for s390 and arm64, introduce an abstract
type for pt_regs and add an asm/bpf_perf_event.h file that concretes
the type.  An asm-generic header file covers the architectures that
export pt_regs today.

The arch-specific enablement for s390 and arm64 follows in separate
commits.

Reported-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Fixes: 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type")
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

32 files changed, 47 insertions, 5 deletions

diff --git a/arch/alpha/include/uapi/asm/Kbuild b/arch/alpha/include/uapi/asm/Kbuild
index b15bf6bc0e94..14a2e9af97e9 100644
--- a/arch/alpha/include/uapi/asm/Kbuild
+++ b/arch/alpha/include/uapi/asm/Kbuild
@@ -1,2 +1,4 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
+
+generic-y += bpf_perf_event.h
diff --git a/arch/arc/include/uapi/asm/Kbuild b/arch/arc/include/uapi/asm/Kbuild
index fa6d0ff4ff89..170b5db64afe 100644
--- a/arch/arc/include/uapi/asm/Kbuild
+++ b/arch/arc/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/arm/include/uapi/asm/Kbuild b/arch/arm/include/uapi/asm/Kbuild
index 4d53de308ee0..4d1cc1847edf 100644
--- a/arch/arm/include/uapi/asm/Kbuild
+++ b/arch/arm/include/uapi/asm/Kbuild
@@ -7,6 +7,7 @@ generated-y += unistd-oabi.h
 generated-y += unistd-eabi.h
 
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
diff --git a/arch/blackfin/include/uapi/asm/Kbuild b/arch/blackfin/include/uapi/asm/Kbuild
index aa624b4ab655..2240b38c2915 100644
--- a/arch/blackfin/include/uapi/asm/Kbuild
+++ b/arch/blackfin/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
diff --git a/arch/c6x/include/uapi/asm/Kbuild b/arch/c6x/include/uapi/asm/Kbuild
index 67ee896a76a7..26644e15d854 100644
--- a/arch/c6x/include/uapi/asm/Kbuild
+++ b/arch/c6x/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/cris/include/uapi/asm/Kbuild b/arch/cris/include/uapi/asm/Kbuild
index 3687b54bb18e..3470c6e9c7b9 100644
--- a/arch/cris/include/uapi/asm/Kbuild
+++ b/arch/cris/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/frv/include/uapi/asm/Kbuild b/arch/frv/include/uapi/asm/Kbuild
index b15bf6bc0e94..14a2e9af97e9 100644
--- a/arch/frv/include/uapi/asm/Kbuild
+++ b/arch/frv/include/uapi/asm/Kbuild
@@ -1,2 +1,4 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
+
+generic-y += bpf_perf_event.h
diff --git a/arch/h8300/include/uapi/asm/Kbuild b/arch/h8300/include/uapi/asm/Kbuild
index 187aed820e71..2f65f78792cb 100644
--- a/arch/h8300/include/uapi/asm/Kbuild
+++ b/arch/h8300/include/uapi/asm/Kbuild
@@ -2,6 +2,7 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/hexagon/include/uapi/asm/Kbuild b/arch/hexagon/include/uapi/asm/Kbuild
index cb5df3aad3a8..41a176dbb53e 100644
--- a/arch/hexagon/include/uapi/asm/Kbuild
+++ b/arch/hexagon/include/uapi/asm/Kbuild
@@ -2,6 +2,7 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/ia64/include/uapi/asm/Kbuild b/arch/ia64/include/uapi/asm/Kbuild
index 13a97aa2285f..f5c6967a93bb 100644
--- a/arch/ia64/include/uapi/asm/Kbuild
+++ b/arch/ia64/include/uapi/asm/Kbuild
@@ -1,4 +1,5 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y += bpf_perf_event.h
 generic-y += kvm_para.h
diff --git a/arch/m32r/include/uapi/asm/Kbuild b/arch/m32r/include/uapi/asm/Kbuild
index 1c44d3b3eba0..451bf6071c6e 100644
--- a/arch/m32r/include/uapi/asm/Kbuild
+++ b/arch/m32r/include/uapi/asm/Kbuild
@@ -1,5 +1,6 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y += bpf_perf_event.h
 generic-y += kvm_para.h
 generic-y += siginfo.h
diff --git a/arch/m68k/include/uapi/asm/Kbuild b/arch/m68k/include/uapi/asm/Kbuild
index 3717b64a620d..c2e26a44c482 100644
--- a/arch/m68k/include/uapi/asm/Kbuild
+++ b/arch/m68k/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
diff --git a/arch/metag/include/uapi/asm/Kbuild b/arch/metag/include/uapi/asm/Kbuild
index 6ac763d9a3e3..f9eaf07d29f8 100644
--- a/arch/metag/include/uapi/asm/Kbuild
+++ b/arch/metag/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/microblaze/include/uapi/asm/Kbuild b/arch/microblaze/include/uapi/asm/Kbuild
index 06609ca36115..2c6a6bffea32 100644
--- a/arch/microblaze/include/uapi/asm/Kbuild
+++ b/arch/microblaze/include/uapi/asm/Kbuild
@@ -2,6 +2,7 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/mips/include/uapi/asm/Kbuild b/arch/mips/include/uapi/asm/Kbuild
index a0266feba9e6..7a4becd8963a 100644
--- a/arch/mips/include/uapi/asm/Kbuild
+++ b/arch/mips/include/uapi/asm/Kbuild
@@ -1,4 +1,5 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y += bpf_perf_event.h
 generic-y += ipcbuf.h
diff --git a/arch/mn10300/include/uapi/asm/Kbuild b/arch/mn10300/include/uapi/asm/Kbuild
index c94ee54210bc..81271d3af47c 100644
--- a/arch/mn10300/include/uapi/asm/Kbuild
+++ b/arch/mn10300/include/uapi/asm/Kbuild
@@ -1,4 +1,5 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y	+= bpf_perf_event.h
 generic-y	+= siginfo.h
diff --git a/arch/nios2/include/uapi/asm/Kbuild b/arch/nios2/include/uapi/asm/Kbuild
index ffca24da7647..13a3d77b4d7b 100644
--- a/arch/nios2/include/uapi/asm/Kbuild
+++ b/arch/nios2/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/openrisc/include/uapi/asm/Kbuild b/arch/openrisc/include/uapi/asm/Kbuild
index 62286dbeb904..130c16ccba0a 100644
--- a/arch/openrisc/include/uapi/asm/Kbuild
+++ b/arch/openrisc/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/parisc/include/uapi/asm/Kbuild b/arch/parisc/include/uapi/asm/Kbuild
index 196d2a4efb31..286ef5a5904b 100644
--- a/arch/parisc/include/uapi/asm/Kbuild
+++ b/arch/parisc/include/uapi/asm/Kbuild
@@ -2,6 +2,7 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
+generic-y += bpf_perf_event.h
 generic-y += kvm_para.h
 generic-y += param.h
 generic-y += poll.h
diff --git a/arch/powerpc/include/uapi/asm/Kbuild b/arch/powerpc/include/uapi/asm/Kbuild
index 0d960ef78a9a..1a6ed5919ffd 100644
--- a/arch/powerpc/include/uapi/asm/Kbuild
+++ b/arch/powerpc/include/uapi/asm/Kbuild
@@ -1,6 +1,7 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y += bpf_perf_event.h
 generic-y += param.h
 generic-y += poll.h
 generic-y += resource.h
diff --git a/arch/riscv/include/uapi/asm/Kbuild b/arch/riscv/include/uapi/asm/Kbuild
index 5ded96b06352..7e91f4850475 100644
--- a/arch/riscv/include/uapi/asm/Kbuild
+++ b/arch/riscv/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += setup.h
 generic-y += unistd.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/score/include/uapi/asm/Kbuild b/arch/score/include/uapi/asm/Kbuild
index c94ee54210bc..81271d3af47c 100644
--- a/arch/score/include/uapi/asm/Kbuild
+++ b/arch/score/include/uapi/asm/Kbuild
@@ -1,4 +1,5 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y	+= bpf_perf_event.h
 generic-y	+= siginfo.h
diff --git a/arch/sh/include/uapi/asm/Kbuild b/arch/sh/include/uapi/asm/Kbuild
index e28531333efa..ba4d39cb321d 100644
--- a/arch/sh/include/uapi/asm/Kbuild
+++ b/arch/sh/include/uapi/asm/Kbuild
@@ -2,6 +2,7 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/sparc/include/uapi/asm/Kbuild b/arch/sparc/include/uapi/asm/Kbuild
index 2178c78c7c1a..4680ba246b55 100644
--- a/arch/sparc/include/uapi/asm/Kbuild
+++ b/arch/sparc/include/uapi/asm/Kbuild
@@ -1,4 +1,5 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y += bpf_perf_event.h
 generic-y += types.h
diff --git a/arch/tile/include/uapi/asm/Kbuild b/arch/tile/include/uapi/asm/Kbuild
index 5711de0a1b5e..cc439612bcd5 100644
--- a/arch/tile/include/uapi/asm/Kbuild
+++ b/arch/tile/include/uapi/asm/Kbuild
@@ -1,6 +1,7 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/unicore32/include/uapi/asm/Kbuild b/arch/unicore32/include/uapi/asm/Kbuild
index 759a71411169..8611ef980554 100644
--- a/arch/unicore32/include/uapi/asm/Kbuild
+++ b/arch/unicore32/include/uapi/asm/Kbuild
@@ -3,6 +3,7 @@ include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += auxvec.h
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/arch/x86/include/uapi/asm/Kbuild b/arch/x86/include/uapi/asm/Kbuild
index da1489cb64dc..1e901e421f2d 100644
--- a/arch/x86/include/uapi/asm/Kbuild
+++ b/arch/x86/include/uapi/asm/Kbuild
@@ -1,6 +1,7 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
+generic-y += bpf_perf_event.h
 generated-y += unistd_32.h
 generated-y += unistd_64.h
 generated-y += unistd_x32.h
diff --git a/arch/xtensa/include/uapi/asm/Kbuild b/arch/xtensa/include/uapi/asm/Kbuild
index a5bcdfb890f1..837d4dd76785 100644
--- a/arch/xtensa/include/uapi/asm/Kbuild
+++ b/arch/xtensa/include/uapi/asm/Kbuild
@@ -2,6 +2,7 @@
 include include/uapi/asm-generic/Kbuild.asm
 
 generic-y += bitsperlong.h
+generic-y += bpf_perf_event.h
 generic-y += errno.h
 generic-y += fcntl.h
 generic-y += ioctl.h
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 2c9c87d8a0c1..7546822a1d74 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -15,6 +15,7 @@
 #define _LINUX_PERF_EVENT_H
 
 #include <uapi/linux/perf_event.h>
+#include <uapi/linux/bpf_perf_event.h>
 
 /*
  * Kernel-internal data types and definitions:
@@ -787,7 +788,7 @@ struct perf_output_handle {
 };
 
 struct bpf_perf_event_data_kern {
-	struct pt_regs *regs;
+	bpf_user_pt_regs_t *regs;
 	struct perf_sample_data *data;
 	struct perf_event *event;
 };
@@ -1177,6 +1178,9 @@ extern void perf_bp_event(struct perf_event *event, void *data);
 		(user_mode(regs) ? PERF_RECORD_MISC_USER : PERF_RECORD_MISC_KERNEL)
 # define perf_instruction_pointer(regs)	instruction_pointer(regs)
 #endif
+#ifndef perf_arch_bpf_user_pt_regs
+# define perf_arch_bpf_user_pt_regs(regs) regs
+#endif
 
 static inline bool has_branch_stack(struct perf_event *event)
 {
diff --git a/include/uapi/asm-generic/bpf_perf_event.h b/include/uapi/asm-generic/bpf_perf_event.h
new file mode 100644
index 000000000000..53815d2cd047
--- /dev/null
+++ b/include/uapi/asm-generic/bpf_perf_event.h
@@ -0,0 +1,9 @@
+#ifndef _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__
+#define _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__
+
+#include <linux/ptrace.h>
+
+/* Export kernel pt_regs structure */
+typedef struct pt_regs bpf_user_pt_regs_t;
+
+#endif /* _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__ */
diff --git a/include/uapi/linux/bpf_perf_event.h b/include/uapi/linux/bpf_perf_event.h
index af549d4ecf1b..8f95303f9d80 100644
--- a/include/uapi/linux/bpf_perf_event.h
+++ b/include/uapi/linux/bpf_perf_event.h
@@ -8,11 +8,10 @@
 #ifndef _UAPI__LINUX_BPF_PERF_EVENT_H__
 #define _UAPI__LINUX_BPF_PERF_EVENT_H__
 
-#include <linux/types.h>
-#include <linux/ptrace.h>
+#include <asm/bpf_perf_event.h>
 
 struct bpf_perf_event_data {
-	struct pt_regs regs;
+	bpf_user_pt_regs_t regs;
 	__u64 sample_period;
 };
 
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 16beab4767e1..ba957b9812b3 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7987,11 +7987,11 @@ static void bpf_overflow_handler(struct perf_event *event,
 {
 	struct bpf_perf_event_data_kern ctx = {
 		.data = data,
-		.regs = regs,
 		.event = event,
 	};
 	int ret = 0;
 
+	ctx.regs = perf_arch_bpf_user_pt_regs(regs);
 	preempt_disable();
 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
 		goto out;