[PATCHv2 net 1/3] samples/bpf: Fix build breakage with map_perf_test_user.c

[PATCHv2 net 1/3] samples/bpf: Fix build breakage with map_perf_test_user.c

[Naveen N. Rao]

Building BPF samples is failing with the below error:

samples/bpf/map_perf_test_user.c: In function ‘main’:
samples/bpf/map_perf_test_user.c:134:9: error: variable ‘r’ has
initializer but incomplete type
  struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
         ^
samples/bpf/map_perf_test_user.c:134:21: error: ‘RLIM_INFINITY’
undeclared (first use in this function)
  struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
                     ^
samples/bpf/map_perf_test_user.c:134:21: note: each undeclared
identifier is reported only once for each function it appears in
samples/bpf/map_perf_test_user.c:134:9: warning: excess elements in
struct initializer [enabled by default]
  struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
         ^
samples/bpf/map_perf_test_user.c:134:9: warning: (near initialization
for ‘r’) [enabled by default]
samples/bpf/map_perf_test_user.c:134:9: warning: excess elements in
struct initializer [enabled by default]
samples/bpf/map_perf_test_user.c:134:9: warning: (near initialization
for ‘r’) [enabled by default]
samples/bpf/map_perf_test_user.c:134:16: error: storage size of ‘r’
isn’t known
  struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
                ^
samples/bpf/map_perf_test_user.c:139:2: warning: implicit declaration of
function ‘setrlimit’ [-Wimplicit-function-declaration]
  setrlimit(RLIMIT_MEMLOCK, &r);
  ^
samples/bpf/map_perf_test_user.c:139:12: error: ‘RLIMIT_MEMLOCK’
undeclared (first use in this function)
  setrlimit(RLIMIT_MEMLOCK, &r);
            ^
samples/bpf/map_perf_test_user.c:134:16: warning: unused variable ‘r’
[-Wunused-variable]
  struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
                ^
make[2]: *** [samples/bpf/map_perf_test_user.o] Error 1

Fix this by including the necessary header file.

Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
v2: no changes

 samples/bpf/map_perf_test_user.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
index 95af56e..3147377 100644
--- a/samples/bpf/map_perf_test_user.c
+++ b/samples/bpf/map_perf_test_user.c
@@ -17,6 +17,7 @@
 #include <linux/bpf.h>
 #include <string.h>
 #include <time.h>
+#include <sys/resource.h>
 #include "libbpf.h"
 #include "bpf_load.h"
 
-- 
2.7.4

[PATCHv2 net 2/3] samples/bpf: Use llc in PATH, rather than a hardcoded value

[Naveen N. Rao]

While at it, remove the generation of .s files and fix some typos in the
related comment.

Cc: Alexei Starovoitov <ast@fb.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
v2: removed generation of .s files

 samples/bpf/Makefile | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 502c9fc..b820cc9 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -76,16 +76,10 @@ HOSTLOADLIBES_offwaketime += -lelf
 HOSTLOADLIBES_spintest += -lelf
 HOSTLOADLIBES_map_perf_test += -lelf -lrt
 
-# point this to your LLVM backend with bpf support
-LLC=$(srctree)/tools/bpf/llvm/bld/Debug+Asserts/bin/llc
-
-# asm/sysreg.h inline assmbly used by it is incompatible with llvm.
-# But, ehere is not easy way to fix it, so just exclude it since it is
+# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
+# But, there is no easy way to fix it, so just exclude it since it is
 # useless for BPF samples.
 $(obj)/%.o: $(src)/%.c
 	clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
 		-D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
-		-O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@
-	clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
-		-D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
-		-O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=asm -o $@.s
+		-O2 -emit-llvm -c $< -o -| llc -march=bpf -filetype=obj -o $@
-- 
2.7.4

Re: [PATCHv2 net 2/3] samples/bpf: Use llc in PATH, rather than a hardcoded value

[Alexei Starovoitov]

On Mon, Apr 04, 2016 at 10:31:33PM +0530, Naveen N. Rao wrote:
> While at it, remove the generation of .s files and fix some typos in the
> related comment.
> 
> Cc: Alexei Starovoitov <ast@fb.com>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

Acked-by: Alexei Starovoitov <ast@kernel.org>

Re: [PATCHv2 net 2/3] samples/bpf: Use llc in PATH, rather than a hardcoded value

[David Miller]

From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Date: Mon,  4 Apr 2016 22:31:33 +0530

> While at it, remove the generation of .s files and fix some typos in the
> related comment.
> 
> Cc: Alexei Starovoitov <ast@fb.com>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

Applied.

[PATCHv2 net 3/3] samples/bpf: Enable powerpc support

[Naveen N. Rao]

Add the necessary definitions for building bpf samples on ppc.

Since ppc doesn't store function return address on the stack, modify how
PT_REGS_RET() and PT_REGS_FP() work.

Also, introduce PT_REGS_IP() to access the instruction pointer.

Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
v2: updated macros using ({ }) gcc extension as per Alexei

 samples/bpf/bpf_helpers.h   | 26 ++++++++++++++++++++++++++
 samples/bpf/spintest_kern.c |  2 +-
 samples/bpf/tracex2_kern.c  |  4 ++--
 samples/bpf/tracex4_kern.c  |  2 +-
 4 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h
index 9363500..7904a2a 100644
--- a/samples/bpf/bpf_helpers.h
+++ b/samples/bpf/bpf_helpers.h
@@ -82,6 +82,7 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag
 #define PT_REGS_FP(x) ((x)->bp)
 #define PT_REGS_RC(x) ((x)->ax)
 #define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->ip)
 
 #elif defined(__s390x__)
 
@@ -94,6 +95,7 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag
 #define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
 #define PT_REGS_RC(x) ((x)->gprs[2])
 #define PT_REGS_SP(x) ((x)->gprs[15])
+#define PT_REGS_IP(x) ((x)->ip)
 
 #elif defined(__aarch64__)
 
@@ -106,6 +108,30 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag
 #define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */
 #define PT_REGS_RC(x) ((x)->regs[0])
 #define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->pc)
+
+#elif defined(__powerpc__)
+
+#define PT_REGS_PARM1(x) ((x)->gpr[3])
+#define PT_REGS_PARM2(x) ((x)->gpr[4])
+#define PT_REGS_PARM3(x) ((x)->gpr[5])
+#define PT_REGS_PARM4(x) ((x)->gpr[6])
+#define PT_REGS_PARM5(x) ((x)->gpr[7])
+#define PT_REGS_RC(x) ((x)->gpr[3])
+#define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->nip)
 
 #endif
+
+#ifdef __powerpc__
+#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })
+#define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
+#else
+#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({				\
+		bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
+#define BPF_KRETPROBE_READ_RET_IP(ip, ctx)	({				\
+		bpf_probe_read(&(ip), sizeof(ip),				\
+				(void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
+#endif
+
 #endif
diff --git a/samples/bpf/spintest_kern.c b/samples/bpf/spintest_kern.c
index 4b27619..ce0167d 100644
--- a/samples/bpf/spintest_kern.c
+++ b/samples/bpf/spintest_kern.c
@@ -34,7 +34,7 @@ struct bpf_map_def SEC("maps") stackmap = {
 #define PROG(foo) \
 int foo(struct pt_regs *ctx) \
 { \
-	long v = ctx->ip, *val; \
+	long v = PT_REGS_IP(ctx), *val; \
 \
 	val = bpf_map_lookup_elem(&my_map, &v); \
 	bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c
index 09c1adc..6d6eefd 100644
--- a/samples/bpf/tracex2_kern.c
+++ b/samples/bpf/tracex2_kern.c
@@ -27,10 +27,10 @@ int bpf_prog2(struct pt_regs *ctx)
 	long init_val = 1;
 	long *value;
 
-	/* x64/s390x specific: read ip of kfree_skb caller.
+	/* read ip of kfree_skb caller.
 	 * non-portable version of __builtin_return_address(0)
 	 */
-	bpf_probe_read(&loc, sizeof(loc), (void *)PT_REGS_RET(ctx));
+	BPF_KPROBE_READ_RET_IP(loc, ctx);
 
 	value = bpf_map_lookup_elem(&my_map, &loc);
 	if (value)
diff --git a/samples/bpf/tracex4_kern.c b/samples/bpf/tracex4_kern.c
index ac46714..6dd8e38 100644
--- a/samples/bpf/tracex4_kern.c
+++ b/samples/bpf/tracex4_kern.c
@@ -40,7 +40,7 @@ int bpf_prog2(struct pt_regs *ctx)
 	long ip = 0;
 
 	/* get ip address of kmem_cache_alloc_node() caller */
-	bpf_probe_read(&ip, sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip)));
+	BPF_KRETPROBE_READ_RET_IP(ip, ctx);
 
 	struct pair v = {
 		.val = bpf_ktime_get_ns(),
-- 
2.7.4

Re: [PATCHv2 net 3/3] samples/bpf: Enable powerpc support

[Alexei Starovoitov]

On Mon, Apr 04, 2016 at 10:31:34PM +0530, Naveen N. Rao wrote:
> Add the necessary definitions for building bpf samples on ppc.
> 
> Since ppc doesn't store function return address on the stack, modify how
> PT_REGS_RET() and PT_REGS_FP() work.
> 
> Also, introduce PT_REGS_IP() to access the instruction pointer.
> 
> Cc: Alexei Starovoitov <ast@fb.com>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

Acked-by: Alexei Starovoitov <ast@kernel.org>

Re: [PATCHv2 net 3/3] samples/bpf: Enable powerpc support

[David Miller]

From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Date: Mon,  4 Apr 2016 22:31:34 +0530

> Add the necessary definitions for building bpf samples on ppc.
> 
> Since ppc doesn't store function return address on the stack, modify how
> PT_REGS_RET() and PT_REGS_FP() work.
> 
> Also, introduce PT_REGS_IP() to access the instruction pointer.
> 
> Cc: Alexei Starovoitov <ast@fb.com>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

Applied.

Re: [PATCHv2 net 1/3] samples/bpf: Fix build breakage with map_perf_test_user.c

[David Miller]

From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Date: Mon,  4 Apr 2016 22:31:32 +0530

> Building BPF samples is failing with the below error:
 ...
> Fix this by including the necessary header file.
> 
> Cc: Alexei Starovoitov <ast@fb.com>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Alexei Starovoitov <ast@kernel.org>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

Applied.