bug#29654: Manual database index.db embeds timestamps

[Ludovic Courtès]

address@hidden (Ludovic Courtès) skribis:

> ==8395== Syscall param write(buf) points to uninitialised byte(s)
> ==8395==    at 0x53E4A8D: ??? (in 
> /gnu/store/3h31zsqxjjg52da5gp3qmhkh4x8klhah-glibc-2.25/lib/libpthread-2.25.so)
> ==8395==    by 0xACAF44D: _gdbm_full_write (in 
> /gnu/store/kg8ffb14msfnc9aivxj6djrl51g9b3zz-gdbm-1.13/lib/libgdbm.so.4.0.0)
> ==8395==    by 0xACAC6AD: gdbm_fd_open (in 
> /gnu/store/kg8ffb14msfnc9aivxj6djrl51g9b3zz-gdbm-1.13/lib/libgdbm.so.4.0.0)

This is almost certainly an uninitialized malloc’d area that goes
straight to disk as can be seen by running the script I gave before with
‘MALLOC_PERTURB_’ set:

--8<---------------cut here---------------start------------->8---
address@hidden ~/src/guix$ MALLOC_PERTURB_=22 ./pre-inst-env guile t.scm

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")
  C-c C-c
address@hidden ~/src/guix$ MALLOC_PERTURB_=44 ./pre-inst-env guile t.scm

;;; (33554432 "03kl992ypwxxp4cplbhz05b04ihjh96d3pldwgz7qaj4ls0qssr3")

;;; (33554432 "03kl992ypwxxp4cplbhz05b04ihjh96d3pldwgz7qaj4ls0qssr3")

;;; (33554432 "03kl992ypwxxp4cplbhz05b04ihjh96d3pldwgz7qaj4ls0qssr3")

;;; (33554432 "03kl992ypwxxp4cplbhz05b04ihjh96d3pldwgz7qaj4ls0qssr3")
  C-c C-c
address@hidden ~/src/guix$ MALLOC_PERTURB_=22 ./pre-inst-env guile t.scm

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")

;;; (33554432 "18rzgjskkgllwfkdyx7gbcc3z6aqsqm9lm6dzs9yrw9z7ppqx0na")
--8<---------------cut here---------------end--------------->8---

So for now, until gdbm is fixed, we can always work around the issue by
setting MALLOC_PERTURB_.

How does that sound?

Ludo’.