Hi Ravitheja, thanks for the logging output. It does look like the assembly profiling is failing for some reason, and with your patch we fall back to using the eh_frame instructions and it succeeds. I'll look at the patch closely tomorrow (I meant to do it tonight but I'm running out of time before I need to head home) - but I'm just curious what lldb will report for
(lldb) image show-unwind -n __kernel_vsyscall when you have the process running. Looking at the assembly instructions, it seems like the assembly language profile inspection should have done the right thing here. The rule "CFA=ebp+16 => ebp=[CFA-16] esp=CFA+0 eip=[CFA-4]" looks right to me at this point in the function. Thanks! Jason > On Dec 1, 2015, at 2:06 AM, Ravitheja Addepally > <ravitheja.addepa...@intel.com> wrote: > > ravitheja added a comment. > > > Here is the log without my patch - > > > th1/fr0 with pc value of 0xf7fd9d80, symbol name is '__kernel_vsyscall' > (i386) [vdso](0x00000000f7fd9000): Reading EH frame info > th1/fr0 0x00000000f7fd9d75: CFA=ebp+16 => ebp=[CFA-16] esp=CFA+0 eip=[CFA-4] > > th1/fr0 Got an invalid CFA register value - reg ebp (6), value 0x0 > th1/fr0 could not read CFA register for this frame. > th1 Unwind of this thread is complete. > Process 99000 stopped > > > > After the patch -> > > > th1/fr0 with pc value of 0xf7fd9d80, symbol name is '__kernel_vsyscall' > (i386) [vdso](0x00000000f7fd9000): Reading EH frame info > th1/fr0 0x00000000f7fd9d75: CFA=ebp+16 => ebp=[CFA-16] esp=CFA+0 eip=[CFA-4] > > th1/fr0 Got an invalid CFA register value - reg ebp (6), value 0x0 > th1/fr0 supplying caller's saved eip (8)'s location using assembly insn > profiling UnwindPlan > th1/fr0 supplying caller's register eip (8) from the stack, saved at CFA plus > offset -4 [saved at 0xfffffffffffffffb] > th1/fr0 CFA is 0xffffd2d4: Register esp (7) contents are 0xffffd2c4, offset > is 16 > th1/fr0 requested caller's saved PC but this UnwindPlan uses a RA reg; > getting eip (8) instead > th1/fr0 supplying caller's saved eip (8)'s location using eh_frame CFI > UnwindPlan > th1/fr0 supplying caller's register eip (8) from the stack, saved at CFA plus > offset -4 [saved at 0xffffd2d0] > th1/fr0 trying to unwind from this function with the UnwindPlan 'eh_frame > CFI' because UnwindPlan 'assembly insn profiling' failed. > th1/fr0 initialized frame current pc is 0xf7fd9d80 cfa is 0xffffd2d4 using > eh_frame CFI UnwindPlan > th1/fr0 supplying caller's saved eip (8)'s location, cached > th1/fr1 pc = 0xf7e40607 > th1/fr0 supplying caller's saved ebp (6)'s location using eh_frame CFI > UnwindPlan > th1/fr0 supplying caller's register ebp (6) from the stack, saved at CFA plus > offset -16 [saved at 0xffffd2c4] > th1/fr1 fp = 0x0 > th1/fr0 supplying caller's stack pointer esp (7) value, computed from CFA > th1/fr1 sp = 0xffffd2d4 > th1/fr1 with pc value of 0xf7e40607, symbol name is 'gsignal' _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
