From e925aaaa2be13aa7c43f6515c4678eccfef65e85 Mon Sep 17 00:00:00 2001
From: Martin Teichmann <martin.teichmann@xfel.eu>
Date: Tue, 29 Dec 2020 16:07:10 +0000
Subject: [PATCH] more generalized memory access
---
ebpf.py | 37 +++++++++++++++++++++++--------------
1 file changed, 23 insertions(+), 14 deletions(-)
diff --git a/ebpf.py b/ebpf.py
index 0705b47..b904b87 100644
--- a/ebpf.py
+++ b/ebpf.py
@@ -271,12 +271,12 @@ class Expression:
@contextmanager
def calculate(self, dst, long, signed, force=False):
with self.ebpf.get_free_register(dst) as dst:
- with self.get_address(dst, long, signed):
- self.ebpf.append(Opcode.LD, dst, dst, 0, 0)
- yield dst, False, self.signed
+ with self.get_address(dst, long, signed) as (src, bits):
+ self.ebpf.append(Opcode.LD + bits, dst, src, 0, 0)
+ yield dst, long, self.signed
@contextmanager
- def get_address(self, dst, long, signed):
+ def get_address(self, dst, long, signed, force=False):
with self.ebpf.get_stack(4 + 4 * long) as stack:
with self.calculate(dst, long, signed) as (src, _, _):
self.ebpf.append(Opcode.STX + Opcode.DW * long,
@@ -451,14 +451,19 @@ class Memory(Expression):
def calculate(self, dst, long, signed, force=False):
if not long and self.bits == Opcode.DW:
raise AssembleError("cannot compile")
- with self.ebpf.get_free_register(dst) as dst:
- if isinstance(self.address, Sum):
+ if isinstance(self.address, Sum):
+ with self.ebpf.get_free_register(dst) as dst:
self.ebpf.append(Opcode.LD + self.bits, dst,
self.address.left.no, self.address.right, 0)
- else:
- with self.address.calculate(dst, None, None) as (src, _, _):
- self.ebpf.append(Opcode.LD + self.bits, dst, src, 0, 0)
- yield dst, long, self.signed
+ yield dst, long, self.signed
+ else:
+ with super().calculate(dst, long, signed, force) as ret:
+ yield ret
+
+ @contextmanager
+ def get_address(self, dst, long, signed, force=False):
+ with self.address.calculate(dst, None, None) as (src, _, _):
+ yield src, self.bits
def contains(self, no):
return self.address.contains(no)
@@ -526,7 +531,7 @@ class HashGlobalVar(Expression):
self.signed = signed
@contextmanager
- def get_address(self, dst, long, signed):
+ def get_address(self, dst, long, signed, force=False):
if long:
raise AssembleError("HashMap is only for words")
if signed != self.signed:
@@ -539,8 +544,12 @@ class HashGlobalVar(Expression):
self.ebpf.call(1)
with self.ebpf.If(self.ebpf.r0 == 0):
self.ebpf.exit()
- self.ebpf.append(Opcode.MOV + Opcode.LONG + Opcode.REG, dst, 0, 0, 0)
- yield
+ print("bla", dst, force)
+ if dst != 0 and force:
+ self.ebpf.append(Opcode.MOV + Opcode.LONG + Opcode.REG, dst, 0, 0, 0)
+ else:
+ dst = 0
+ yield dst, Opcode.W
class HashGlobalVarDesc:
@@ -572,7 +581,7 @@ class HashGlobalVarDesc:
pack("i" if self.signed else "I", value), 0)
return
with ebpf.save_registers([3]):
- with value.get_address(3, False, self.signed):
+ with value.get_address(3, False, self.signed, True):
with ebpf.save_registers([0, 1, 2, 4, 5]), \
ebpf.get_stack(4) as stack:
ebpf.r1 = ebpf.get_fd(ebpf.__dict__[self.name].fd)
--
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