Archive for the ‘Mac OS X’ Category

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GDB Annoyances: Incomplete Stack Trace

Sunday, March 25th, 2012

Users of WinDbg debugger accustomed to full thread stack traces will wonder whether a thread starts from main:

(gdb) where
#0  0x000000010d3b0e90 in bar () at main.c:15
#1  0x000000010d3b0ea9 in foo () at main.c:20
#2  0x000000010d3b0ec4 in main (argc=1,
argv=0x7fff6cfafbf8) at main.c:25

Of course, not and by default a stack trace is shown starting from main function. You can change this behavior by using the following command:

(gdb) set backtrace past-main

Now we see an additional frame:

(gdb) where
#0  0x000000010d3b0e90 in bar () at main.c:15
#1  0x000000010d3b0ea9 in foo () at main.c:20
#2  0x000000010d3b0ec4 in main (argc=1,
argv=0x7fff6cfafbf8) at main.c:25
#3  0×000000010d3b0e74 in start ()

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Forthcoming Training: Accelerated Mac OS X Core Dump Analysis

Posted in Core Dump Analysis, Crash Dump Analysis, Debugging, GDB Annoyances, GDB for WinDbg Users, Mac Crash Corner, Mac OS X | 1 Comment »

Crash Dump Analysis Patterns (Part 6b, Mac OS X)

Sunday, March 25th, 2012

This is a Mac OS X / GDB counterpart to NULL Pointer (data) pattern previously described for Windows platforms:

(gdb) bt
#0  0×000000010d3b0e90 in bar () at main.c:15
#1  0×000000010d3b0ea9 in foo () at main.c:20
#2  0×000000010d3b0ec4 in main (argc=1,
argv=0×7fff6cfafbf8) at main.c:25

(gdb) disassemble
Dump of assembler code for function bar:
0x000000010d3b0e80 <bar+0>: push   %rbp
0×000000010d3b0e81 <bar+1>: mov    %rsp,%rbp
0×000000010d3b0e84 <bar+4>: movq   $0×0,-0×8(%rbp)
0×000000010d3b0e8c <bar+12>: mov    -0×8(%rbp),%rax
0×000000010d3b0e90 <bar+16>: movl   $0×1,(%rax)
0×000000010d3b0e96 <bar+22>: pop    %bp
0×000000010d3b0e97 <bar+23>: retq
End of assembler dump.

(gdb) p/x $rax
$1 = 0×0

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Forthcoming Training: Accelerated Mac OS X Core Dump Analysis

Posted in Assembly Language, Core Dump Analysis, Crash Dump Analysis, Crash Dump Patterns, Debugging, GDB for WinDbg Users, Mac Crash Corner, Mac OS X, Software Defect Construction, x64 Mac OS X | No Comments »

Accelerated Mac OS X Core Dump Analysis Training

Saturday, March 3rd, 2012

Accelerated Mac OS X Core Dump Analysis Logo

Memory Dump Analysis Services organizes a new training course:

Description: Learn how to analyze app crashes and freezes, navigate through process core memory dump space and diagnose corruption, memory leaks, CPU spikes, blocked threads, deadlocks, wait chains, and much more. We use a unique and innovative pattern-driven analysis approach to speed up the learning curve. The training consists of practical step-by-step exercises using Xcode and GDB environments highlighting various patterns diagnosed in 64-bit process core memory dumps. The training also includes an overview of relevant similarities and differences between Windows and Mac OS X user space memory dump analysis useful for engineers with Wintel background.

If you are registered you are allowed to optionally submit your app core dumps before the training. This will allow us in addition to the carefully constructed problems tailor additional examples to the needs of the attendees.

The training consists of 2 two-hour sessions. When you finish the training you additionally get:

  1. A full transcript in PDF format (retail price $200)
  2. 6 volumes of Memory Dump Analysis Anthology in PDF format (retail price $120)
  3. A personalized attendance certificate with unique CID (PDF format)
  4. Mac OS X Debugging: Practical Foundations in PDF format (retail price $15)
  5. Free Dump Analysis World Network membership including updates to full PDF transcript Q&A section

Prerequisites: Basic Mac OS X troubleshooting and debugging

Audience: Software technical support and escalation engineers, system administrators, software developers and quality assurance engineers.

Session 1: October 19, 2012 4:00 PM - 6:00 PM BST
Session 2: October 22, 2012 4:00 PM - 6:00 PM BST

Price: 210 USD

Space is limited.
Reserve your remote training seat now at:
https://student.gototraining.com/r/3803636572165653760

If you are mainly interested in Windows memory dump analysis there is another course available:

Accelerated Windows Memory Dump Analysis

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Posted in Announcements, Assembly Language, Crash Dump Analysis, Crash Dump Patterns, Debugging, Escalation Engineering, Mac Crash Corner, Mac OS X, Memory Dump Analysis Services, Software Engineering, Software Technical Support, Testing, Training and Seminars | No Comments »

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