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Comment by kleiba | Hacker News Reader

Firefox is about the only piece of software in my setup that occasionally crashes. I say "occasionally" for lack of a better word, it's not "all the time", but it is definitely more than I would want to.

If that was caused by bad memory, I would expect other software to be similarly affected and hence crash with about comparable frequency. However, it looks like I'm falling more into the other 90% of cases (unsurprisingly) because I do not observe other software crashing as much as firefox does.

Also, this whole crashing business is a fairly recent effect - I've been running firefox for forever and I cannot remember when it last was as much of an issue as it has become recently for me.

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Just check your memory with memtest.

Two years ago, I've had Factorio crash once on a null pointer exception. I reported the crash to the devs and, likely because the crash place had a null check, they told me my memory was bad. Same as you I said "wait no, no other software ever crashed weirdly on this machine!", but they were adamant.

Lo and behold, I indeed had one of my four ram sticks with a few bad addresses. Not much, something like 10-15 addresses tops. You need bad luck to hit one of those addresses when the total memory is 64GB. It's likely the null pointer check got flipped.

Browsers are good candidates to find bad memory: they eat a lot of ram, they scatter data around, they have a large chunk, and have JITs where a lot of machine code gets loaded left and right.

I think the most salient point about Factorio here is that its CPU-side native core was largely hammered out by 2018, most of the development since then has been in Lua or GPU-side. The devs could be quite confident their code didn't have any unhandled null pointers. That's not really the case for Chromium or (God help us) WebKit.

… and are almost always active so that would add to that spread, wouldn’t it?

I spend probably thousands of hours in Firefox every year and I don't think I've ever had it crash.

Same. I don't think I've had a crash in 10+ years.

Same for me, it's simply never crashing for my day to day use. It doesn't mean there aren't idiosyncratic cases out there but anecdata can easily paint any number of pictures.

Of course, nobody is claiming that there aren't lots of Firefox crashes which are caused by bugs in Firefox. Quite the opposite, based on these figures. What people find interesting is that the amount they're suspecting are down to hardware faults is way higher than most people would have expected.

It depends on what you bitflip.

I once had a bitflip pattern causing lowercase ascii to turn into uppercase ascii in a case insensitive system. Everything was fine until it tried to uppercase numbers and things went wrong

The first time I had to deal with faulty ram ( more than 20y ago ), the bug would never trigger unless I used pretty much the whole dimm stick and put meaningful stuff in it etc in my case linking large executables , or untargzipping large source archives.

Flipping a pixel had no impact though

Do you happen to use memory resource limits? I used to run Firefox under some, like everything, to prevent it from potentially making the whole system unresponsible, and at the same time had frequent cases of Firefox showing random visual corruptions and crashes. At some point I realized that it was because it was running out of memory, and didn't check malloc failures, thus just continued to run and corrupting memory. (That was some 6-8 years ago, maybe Firefox does better now?)

You were seeing issues from the graphics driver, not Firefox.

Any memory allocation failing within the browser forces an instant crash unless the callsite explicitly opts in to handling the allocation failure.

"Check malloc failure" is an opt-out feature in browsers, not opt-in. It's the same in Chromium. Failing to check would cause too many security issues. (One more reason new stuff tends to prefer Rust, etc)

Thanks for the info! I guess it also makes sense as I realized after posting, if it did use the result of malloc unused it should crash immediately due to references into the zero page segment, thus can't have been what I saw.

I've had some very bad ram (lots of errors found when tested) and consistently the only thing that actually crashed because of it was Firefox.

For me the only software crashing(CTD ) was Factorio. Nothing else had any issues. I tried removing mods, searching for one that started causing issues. Memtestx86 said everything is OK. Replacing one stick of RAM instantly fixed all issues.

The most frequent crashes I have with Firefox are when I type in a text area (such as this one right now, or on Reddit, for example). The longer the text I type is, the more probable it is that it's going to crash. Or maybe it doesn't crash, just grinds to such a slow pace that it is equivalent to a crash.

My suspicion has always been some kind of a memory leak, but memory corruption also makes sense.

Unfortunately, Chrome (which I use for work - Firefox is for private stuff) has NEVER crashed on me yet. Certainly not in the past 5 years. Which is odd. I'm on Linux btw.

It could be a leak but it could also be an inefficient piece of logic in Firefox. One could imagine that on every keystroke Firefox is scanning the entire input text for typos or malicious inputs whereas Chrome might be scanning only the text before the cursor back until the first whitespace (since the other text is already known).

No.

I almost never get Firefox crashes on Linux, and I don't remember seeing significant slowdowns with text boxes either, at least not simple ones.

How long are the inputs that you get problems with?

I'm quite confident to say that millions of people use Firefox to comment on Reddit or similar sites every day, or write long posts, without seeing this problem.

Without knowing more about your configuration, it's hard to give advice, but definitely worth trying with a clean profile first.

If you don't report this problem upstream it will never get fixed, as obviously no-one else is seeing this. Firefox has a built-in profiler that you can use to report performance problems like this.

Firefox has a long history of denying problems, blaming the user, and fixing the issue years later.

It used to be memory usage, now it's crashing.

Did you actually read the posts that started this topic, or are you being an ass for no reason?

Hint: No-one is claiming memory is to blame for 100% of the Firefox crashes. No-one is claiming it's 99% either.

Which part of my post was being an ass?

Sorry, but I experienced first hand Firefox's memory leaks not being taken seriously. This "bitflips" news is just released, but I fully expect anybody complaining about Firefox crashes to be met with low effort "It's your RAM," responses for the next few years now.

> Firefox is about the only piece of software in my setup that occasionally crashes.

I would add Thunderbird to that list.

run y-cruncher if you'd like to test memory and overall stability. It's decent test and a lot better than memtest (in my experience)

If only the had written Firefox in Rust, they wouldn't have had these issues .

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