Technorama

An omnibus of tech posts by a Futurologist on software development primarily.

Wednesday, 31 July 2024

Plebiscite Greenland only 56,661 population

Greenland risks a plebiscite, that is an influx of more than the current population, who then vote in a referendum for independence from Denmark, where they are an autonomous territory. The Faeroe Islands also have a similar population and risk the same fate.

posted by 東京 # 12:08 0 Comments

Sunday, 30 June 2024

Rate limit and CPU limit for Chrome and Firefox

Don't you often notice a lot of minimised windows are using up 60% CPU. Those pages are rotating animations etc.

Whats the solution? Well it's easy enough to do Ctrl+Z and send SIGINT, then on a shell we only need to type "fg", but what for web browsers? It also will work, but maybe things will timeout.

I'd therefore suggest a button on the top bar to rate limit to 1% CPU and 1% network speed (or 1KB sec), that's probably enough to keep connections open and return the computer to usability.

posted by 東京 # 10:29 0 Comments

Monday, 6 May 2024

The Next Pandemic

Given we've had coronavirus circulating for thousands of years, and various outbreaks like SARS (2002), MERS (2012) and COVID (2019) it looks like given the global nature of travel we'll have another epidemic like SARS or a pandemic like COVID within a range of 6-10 years, the confidence of this date prediction is not high.

posted by 東京 # 19:25 0 Comments

Thursday, 12 October 2023

Secure sandboxes

Seems easy, iPhone keeps getting malware owned by faulty image files.

Sandbox decoders

Run decompressors in a micro sandboxed VM. It it doesn't finish decoding and outputting an uncompressed bitmap file to a ramdrive within one second, just kill the sandbox. Saves being exploited. (Unless the sandbox VM can also be jailbreaked)

Compile the process in the sandbox with AddressSanitizer.

Have a system to automatically upload any coredumps from the sandbox crashes, either then, or after a reboot.

Probably those creating the security exploits will test on real devices a few times before they get a working crack. That gives you chance to get the coredump and backtrace.

posted by 東京 # 13:25 0 Comments

Wednesday, 6 September 2023

gcc attribute nonnull considered harmful

gcc function attributes allow optimizer hints, set attribute nonnull and the optimizer will know it is never going to be a nullptr - so it will remove all nullptr checks!

This is often not what is expected by the humble programmer.

posted by 東京 # 23:10 0 Comments

Monday, 10 April 2023

Chromium debug build with symbols

Navigate here

Click "Last Modified" heading

Then get the build folder number from the file LAST_CHANGE

posted by 東京 # 20:54 0 Comments

Tuesday, 21 February 2023

Custom C/C++ assert example with file line and column information

// -fanalyzer -DNDEBUG -Wno-analyzer-use-of-uninitialized-value

#include <string>
#include <iostream>
#include <string_view>
#include <source_location>

// Pass const std::source_location location = std::source_location::current()
#if NDEBUG
#define myassert(x, s, l)
#else
#define myassert(x, s, l) if(!x)  {printf("%s:%d:%d %s %s\n", l.file_name(), l.line(), l.column(), l.function_name(), s); fflush(stdout); abort();}
#endif

#define TRIGGER_NULLPTR_WARNING 1

std::string make_std_string(const char * const str, const std::source_location location =
               std::source_location::current())
{
    myassert((nullptr != str), "nullptr dereference", location);

#if TRIGGER_NULLPTR_WARNING
    // This line ensures: warning: dereference of NULL '0' [CWE-476] [-Wanalyzer-null-dereference]
    char b = *str; 
#endif

    std::string s(str);
#if TRIGGER_NULLPTR_WARNING
    s[0] = b;
#endif

    return s;
}

int main()
{
    const char * a = NULL;
    std::string result = make_std_string(a);
    std::cout << result;
}

posted by 東京 # 21:39 0 Comments

Archives

February 2003 March 2003 April 2003 August 2004 September 2004 December 2004 May 2005 June 2005 December 2006 January 2007 February 2007 March 2007 April 2007 July 2007 August 2007 September 2007 October 2007 November 2007 December 2007 January 2008 February 2008 March 2008 April 2008 May 2008 June 2008 July 2008 August 2008 September 2008 October 2008 November 2008 December 2008 January 2009 February 2009 March 2009 April 2009 September 2009 November 2009 December 2009 January 2010 April 2010 September 2010 October 2010 November 2010 December 2010 January 2011 February 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 September 2011 October 2011 November 2011 December 2011 January 2012 February 2012 March 2012 April 2012 May 2012 June 2012 July 2012 October 2012 December 2012 March 2013 May 2013 August 2013 September 2013 October 2013 November 2013 March 2014 May 2014 June 2014 July 2014 September 2014 October 2014 December 2014 January 2015 February 2015 March 2015 April 2015 May 2015 June 2015 July 2015 August 2015 September 2015 October 2015 November 2015 December 2015 March 2016 April 2016 May 2016 July 2016 August 2016 September 2016 October 2016 November 2016 December 2016 January 2017 February 2017 March 2017 April 2017 May 2017 June 2017 July 2017 August 2017 September 2017 November 2017 March 2018 April 2018 May 2018 June 2018 August 2018 October 2018 December 2018 January 2019 March 2019 May 2019 August 2019 September 2019 March 2020 April 2020 May 2020 September 2020 October 2020 February 2022 June 2022 July 2022 October 2022 December 2022 February 2023 April 2023 September 2023 October 2023 May 2024 June 2024 July 2024

Subscribe to Posts [Atom]