No use of C via CGO at all. Afaik, there isn't any unsafe use of the string, we are basically reading it from a get parameter (fasthttp server) on an http request and then adding it into this structure, most of the times is just a 5 char string. Out of several millions requests, this panic happens.
I failed to find any kind of race using go race detector, I'm currently doing some more debugging, hopefuly I should have more info/tests soon. El jueves, 2 de mayo de 2019, 20:44:33 (UTC-3), Burak Serdar escribió: > > On Thu, May 2, 2019 at 3:56 PM Ian Lance Taylor <ia...@golang.org > <javascript:>> wrote: > > > > On Thu, May 2, 2019 at 2:50 PM Anthony Martin <al...@pbrane.org > <javascript:>> wrote: > > > > > > What version of Go are you using? > > > > > > XXX ZZZ <emarti...@gmail.com <javascript:>> once said: > > > > fmt.(*pp).fmtString(0xc023c17740, 0x0, 0x5, 0xc000000076) > > > > /usr/local/go/src/fmt/print.go:448 +0x132 > > > > fmt.(*pp).printArg(0xc023c17740, 0x9978e0, 0xc016a68a30, 0x76) > > > > /usr/local/go/src/fmt/print.go:684 +0x880 > > > > fmt.(*pp).doPrintf(0xc023c17740, 0xa6e22f, 0x5, 0xc048c27818, 0x1, > 0x1) > > > > /usr/local/go/src/fmt/print.go:1112 +0x3ff > > > > fmt.Sprintf(0xa6e22f, 0x5, 0xc048c27818, 0x1, 0x1, 0x80, 0xa36200) > > > > /usr/local/go/src/fmt/print.go:214 +0x66 > > > > > > This shows signs of memory corruption. The last argument passed to > > > fmtString (0xc000000076) should be the same as the last argument > > > passed to printArg (0x76 or 'v') but it has some high bits set. Also, > > > the pointer to the format string data changes from 0xa6e22f (which is > > > probably in the .rodata section of the binary) to 0x0. > > > > > > Something is amiss. > > > > The change from 0x76 to 0xc000000076 does not necessarily indicate a > > problem. The stack backtrace does not know the types. The value here > > is a rune, which is 32 bits. The compiler will only set the low order > > 32 bits on the stack, leaving the high order 32 bits unset. So the > > 0xc000000000 could just be garbage left on the stack. > > > > I don't *think* the format string is changing. I think the 0 is from > > the string being printed, not the format string. They both happen to > > be length 5. > > There's something that doesn't make sense here. The 0 is from the > string being printed, it is not the format string. But how can that > be? > > Even if there is a race, the string cannot have a 0 for the slice, can > it? So the other option is when Sprintf is called, the string being > printed is already corrupt. Can there be an overflow somewhere that is > somehow undetected? Any unsafe use in the program? > > > > > > Ian > > > > -- > > You received this message because you are subscribed to the Google > Groups "golang-nuts" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to golan...@googlegroups.com <javascript:>. > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
