On 4/29/17 7:13 PM, David Miller wrote:
From: Alexei Starovoitov <ast@xxxxxx> Date: Sat, 29 Apr 2017 17:48:43 -0700/w/binutils-gdb/bld/binutils/objdump: invalid relocation type 10 /w/binutils-gdb/bld/binutils/objdump: Dwarf Error: found address sizeI discussed this in another email, the relocation numbers I used in binutils do not match what is in LLVM currently. In fact, I thought you guys weren't using relocations in any capacity at all so just picked things from scratch :-)
yeah :) will reply in the other thread. Too many public and internal discussions in the last week. Weekend is the only time to reduce the backlog :) > Please use "--target=bpf-elf" Thanks. That worked. Built the whole thing :) objdump behaves the same way. When compiled by clang with '-g' (gdb) x/10i bpf_prog10x0 <clang version 5.0.0 (trunk 301652) (llvm/trunk 301662)>: ldimm64 r0, 590618314553 0x10 <clang version 5.0.0 (trunk 301652) (llvm/trunk 301662)+16>: stdw [r1+65528], r10 0x18 <clang version 5.0.0 (trunk 301652) (llvm/trunk 301662)+24>: lddw r10, [r1+65528] 0x20 <clang version 5.0.0 (trunk 301652) (llvm/trunk 301662)+32>: add r0, -1879113726 0x28 <clang version 5.0.0 (trunk 301652) (llvm/trunk 301662)+40>: lddw r1, [r0+0]
0x30 <clang version 5.0.0 (trunk 301652) (llvm/trunk 301662)+48>: exit
0x38: Cannot access memory at address 0x38
Even without -g the last line 'Cannot access' is printed.
It seems gdb miscalculates the total func size?
The printing of 'clang version...' is due to '-g'.
Without -g it looks good:
(gdb) x/10i bpf_prog1
0x0 <bpf_prog1>: ldimm64 r1, 590618314553
0x10 <bpf_prog1+16>: stdw [r10+65528], r1
Btw, I'm using this C file for testing:
int bpf_prog1(void *ign)
{
volatile unsigned long t = 0x8983984739ull;
return *(unsigned long *)((0xffffffff8fff0002ull) + t);
}
There was a bug in llvm backend with imm overflow which
was recently fixed.
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