bcc: Add some basic support for MIPS

In order to fix the following errors when running bpf program
on the MIPS Loongson64 platform, add some basic support, with
this patch, running hello_world.py can get the expected result.

 root@linux:/home/loongson/bcc# python examples/hello_world.py
 In file included from <built-in>:3:
 In file included from /virtual/include/bcc/helpers.h:51:
 In file included from include/uapi/linux/if_packet.h:5:
 arch/mips/include/uapi/asm/byteorder.h:17:3: error: "MIPS, but neither __MIPSEB__, nor __MIPSEL__???"
 # error "MIPS, but neither __MIPSEB__, nor __MIPSEL__???"
   ^
 In file included from <built-in>:3:
 In file included from /virtual/include/bcc/helpers.h:53:
 In file included from include/linux/log2.h:12:
 In file included from include/linux/bitops.h:32:
 In file included from arch/mips/include/asm/bitops.h:19:
 In file included from arch/mips/include/asm/barrier.h:11:
 arch/mips/include/asm/addrspace.h:13:10: fatal error: 'spaces.h' file not found
 #include <spaces.h>
         ^~~~~~~~~~
 2 errors generated.
 Traceback (most recent call last):
   File "examples/hello_world.py", line 12, in <module>
     BPF(text='int kprobe__sys_clone(void *ctx) { bpf_trace_printk("Hello, World!\\n"); return 0; }').trace_print()
   File "/usr/lib/python2.7/site-packages/bcc/__init__.py", line 364, in __init__
     raise Exception("Failed to compile BPF module %s" % (src_file or "<text>"))
 Exception: Failed to compile BPF module <text>

 root@linux:/home/loongson/bcc# python examples/hello_world.py
 In file included from <built-in>:3:
 In file included from /virtual/include/bcc/helpers.h:53:
 In file included from include/linux/log2.h:12:
 In file included from include/linux/bitops.h:32:
 arch/mips/include/asm/bitops.h:101:3: error: invalid output constraint '+ZC' in asm
                 __bit_op(*m, __INS "%0, %3, %2, 1", "i"(bit), "r"(~0));
                 ^
 arch/mips/include/asm/bitops.h:40:19: note: expanded from macro '__bit_op'
         : "=&r"(__temp), "+" GCC_OFF_SMALL_ASM()(mem)           \
                          ^
 [...]
 arch/mips/include/asm/atomic.h:154:1: error: invalid output constraint '+ZC' in asm
 arch/mips/include/asm/atomic.h:151:2: note: expanded from macro 'ATOMIC_OPS'
         ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)
         ^
 arch/mips/include/asm/atomic.h:141:4: note: expanded from macro 'ATOMIC_FETCH_OP'
           "+" GCC_OFF_SMALL_ASM() (v->counter)                          \
           ^
 fatal error: too many errors emitted, stopping now [-ferror-limit=]
 20 errors generated.
 Traceback (most recent call last):
   File "examples/hello_world.py", line 12, in <module>
     BPF(text='int kprobe__sys_clone(void *ctx) { bpf_trace_printk("Hello, World!\\n"); return 0; }').trace_print()
   File "/usr/lib/python2.7/site-packages/bcc/__init__.py", line 364, in __init__
     raise Exception("Failed to compile BPF module %s" % (src_file or "<text>"))
 Exception: Failed to compile BPF module <text>

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>

diff --git a/libbpf-tools/Makefile b/libbpf-tools/Makefile
index 5bbd0c42044002b8cd5c4a92904131c8c887267a..87df7e486d2526172269060bb43d8eee0d627b11 100644 (file)
--- a/libbpf-tools/Makefile
+++ b/libbpf-tools/Makefile
@@ -9,7 +9,7 @@ INCLUDES := -I$(OUTPUT)
 CFLAGS := -g -O2 -Wall
 INSTALL ?= install
 prefix ?= /usr/local
-ARCH := $(shell uname -m | sed 's/x86_64/x86/' | sed 's/aarch64/arm64/' | sed 's/ppc64le/powerpc/')
+ARCH := $(shell uname -m | sed 's/x86_64/x86/' | sed 's/aarch64/arm64/' | sed 's/ppc64le/powerpc/' | sed 's/mips.*/mips/')
 
 ifeq ($(wildcard $(ARCH)/),)
 $(error Architecture $(ARCH) is not supported yet. Please open an issue)

diff --git a/src/cc/export/helpers.h b/src/cc/export/helpers.h
index c232441516ccd8e7b71e4cb0058e7a7f7ba08a8f..4aeeb3370d93e230df651cb529f225d67a38a322 100644 (file)
--- a/src/cc/export/helpers.h
+++ b/src/cc/export/helpers.h
@@ -1099,6 +1099,9 @@ int bpf_usdt_readarg_p(int argc, struct pt_regs *ctx, void *buf, u64 len) asm("l
 #elif defined(__TARGET_ARCH_powerpc)
 #define bpf_target_powerpc
 #define bpf_target_defined
+#elif defined(__TARGET_ARCH_mips)
+#define bpf_target_mips
+#define bpf_target_defined
 #else
 #undef bpf_target_defined
 #endif
@@ -1113,6 +1116,8 @@ int bpf_usdt_readarg_p(int argc, struct pt_regs *ctx, void *buf, u64 len) asm("l
 #define bpf_target_arm64
 #elif defined(__powerpc__)
 #define bpf_target_powerpc
+#elif defined(__mips__)
+#define bpf_target_mips
 #endif
 #endif
 
@@ -1161,6 +1166,18 @@ int bpf_usdt_readarg_p(int argc, struct pt_regs *ctx, void *buf, u64 len) asm("l
 #define PT_REGS_RC(x)          ((x)->regs[0])
 #define PT_REGS_SP(x)          ((x)->sp)
 #define PT_REGS_IP(x)          ((x)->pc)
+#elif defined(bpf_target_mips)
+#define PT_REGS_PARM1(x) ((x)->regs[4])
+#define PT_REGS_PARM2(x) ((x)->regs[5])
+#define PT_REGS_PARM3(x) ((x)->regs[6])
+#define PT_REGS_PARM4(x) ((x)->regs[7])
+#define PT_REGS_PARM5(x) ((x)->regs[8])
+#define PT_REGS_PARM6(x) ((x)->regs[9])
+#define PT_REGS_RET(x) ((x)->regs[31])
+#define PT_REGS_FP(x) ((x)->regs[30]) /* Works only with CONFIG_FRAME_POINTER */
+#define PT_REGS_RC(x) ((x)->regs[2])
+#define PT_REGS_SP(x) ((x)->regs[29])
+#define PT_REGS_IP(x) ((x)->cp0_epc)
 #else
 #error "bcc does not support this platform yet"
 #endif

diff --git a/src/cc/frontends/clang/arch_helper.h b/src/cc/frontends/clang/arch_helper.h
index d02feff0212a1f22b40720a41b98cc1b42f6148e..7704fd02d7e8fe810928e790fe5d87d143416d6a 100644 (file)
--- a/src/cc/frontends/clang/arch_helper.h
+++ b/src/cc/frontends/clang/arch_helper.h
@@ -22,6 +22,7 @@ typedef enum {
   BCC_ARCH_PPC_LE,
   BCC_ARCH_S390X,
   BCC_ARCH_ARM64,
+  BCC_ARCH_MIPS,
   BCC_ARCH_X86
 } bcc_arch_t;
 
@@ -43,6 +44,8 @@ static void *run_arch_callback(arch_callback_t fn, bool for_syscall = false)
     return fn(BCC_ARCH_S390X, for_syscall);
 #elif defined(__aarch64__)
     return fn(BCC_ARCH_ARM64, for_syscall);
+#elif defined(__mips__)
+    return fn(BCC_ARCH_MIPS, for_syscall);
 #else
     return fn(BCC_ARCH_X86, for_syscall);
 #endif
@@ -59,6 +62,8 @@ static void *run_arch_callback(arch_callback_t fn, bool for_syscall = false)
     return fn(BCC_ARCH_S390X, for_syscall);
   } else if (!strcmp(archenv, "arm64")) {
     return fn(BCC_ARCH_ARM64, for_syscall);
+  } else if (!strcmp(archenv, "mips")) {
+    return fn(BCC_ARCH_MIPS, for_syscall);
   } else {
     return fn(BCC_ARCH_X86, for_syscall);
   }

diff --git a/src/cc/frontends/clang/b_frontend_action.cc b/src/cc/frontends/clang/b_frontend_action.cc
index da9b8ed9c0fd11e7eb3eb87b4945ab30f2f94f5f..9b3c24893e0b68d5caf375518109ba7abeea356f 100644 (file)
--- a/src/cc/frontends/clang/b_frontend_action.cc
+++ b/src/cc/frontends/clang/b_frontend_action.cc
@@ -57,6 +57,9 @@ const char *calling_conv_regs_s390x[] = {"gprs[2]", "gprs[3]", "gprs[4]",
 const char *calling_conv_regs_arm64[] = {"regs[0]", "regs[1]", "regs[2]",
                                        "regs[3]", "regs[4]", "regs[5]"};
 
+const char *calling_conv_regs_mips[] = {"regs[4]", "regs[5]", "regs[6]",
+                                       "regs[7]", "regs[8]", "regs[9]"};
+
 void *get_call_conv_cb(bcc_arch_t arch, bool for_syscall)
 {
   const char **ret;
@@ -72,6 +75,9 @@ void *get_call_conv_cb(bcc_arch_t arch, bool for_syscall)
     case BCC_ARCH_ARM64:
       ret = calling_conv_regs_arm64;
       break;
+    case BCC_ARCH_MIPS:
+      ret = calling_conv_regs_mips;
+      break;
     default:
       if (for_syscall)
         ret = calling_conv_syscall_regs_x86;

diff --git a/src/cc/frontends/clang/kbuild_helper.cc b/src/cc/frontends/clang/kbuild_helper.cc
index c4e0f074a50e76b667901b3ab4a2b161874fc98b..5bed2721b6c4dd5280c13d898411f19b14dde733 100644 (file)
--- a/src/cc/frontends/clang/kbuild_helper.cc
+++ b/src/cc/frontends/clang/kbuild_helper.cc
@@ -115,6 +115,11 @@ int KBuildHelper::get_flags(const char *uname_machine, vector<string> *cflags) {
     cflags->push_back("-Iinclude/generated/uapi");
   }
 
+  if (arch == "mips") {
+    cflags->push_back("-Iarch/mips/include/asm/mach-loongson64");
+    cflags->push_back("-Iarch/mips/include/asm/mach-generic");
+  }
+
   cflags->push_back("-include");
   cflags->push_back("./include/linux/kconfig.h");
   cflags->push_back("-D__KERNEL__");

diff --git a/src/cc/frontends/clang/loader.cc b/src/cc/frontends/clang/loader.cc
index a274f0fe687765a2cee6e7442f41afda95078144..9bd8a65044d4c32b9ca3f81aa4f5b077a1a8d57f 100644 (file)
--- a/src/cc/frontends/clang/loader.cc
+++ b/src/cc/frontends/clang/loader.cc
@@ -195,6 +195,15 @@ int ClangLoader::parse(unique_ptr<llvm::Module> *mod, TableStorage &ts,
                                    "-fno-asynchronous-unwind-tables",
                                    "-x", "c", "-c", abs_file.c_str()});
 
+  const char *arch = getenv("ARCH");
+  if (!arch)
+    arch = un.machine;
+
+  if (!strncmp(arch, "mips", 4)) {
+    flags_cstr.push_back("-D__MIPSEL__");
+    flags_cstr.push_back("-D_MIPS_SZLONG=64");
+  }
+
   KBuildHelper kbuild_helper(kpath_env ? kpath : kdir, has_kpath_source);
 
   vector<string> kflags;
@@ -270,6 +279,9 @@ void *get_clang_target_cb(bcc_arch_t arch, bool for_syscall)
     case BCC_ARCH_ARM64:
       ret = "aarch64-unknown-linux-gnu";
       break;
+    case BCC_ARCH_MIPS:
+      ret = "mips64el-unknown-linux-gnuabi64";
+      break;
     default:
       ret = "x86_64-unknown-linux-gnu";
   }