Bug 246330
| Summary: | ptrace looses track of a forked child | ||||||
|---|---|---|---|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | John D. Ramsdell <ramsdell> | ||||
| Component: | kernel | Assignee: | Kernel Maintainer List <kernel-maint> | ||||
| Status: | CLOSED CURRENTRELEASE | QA Contact: | Fedora Extras Quality Assurance <extras-qa> | ||||
| Severity: | low | Docs Contact: | |||||
| Priority: | low | ||||||
| Version: | 7 | CC: | roland | ||||
| Target Milestone: | --- | ||||||
| Target Release: | --- | ||||||
| Hardware: | i386 | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | 2.6.22.1-27.fc7 | Doc Type: | Bug Fix | ||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2007-07-23 19:03:19 UTC | Type: | --- | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Attachments: |
|
||||||
Created attachment 158292 [details]
Shows ptrace loosing track of a forked process
Kernel 3241 has new ptrace code -- we should have a copy available for testing tomorrow. I just finished setting up a rawhide machine. [ramsdell@drawlight audit]$ uname -a Linux drawlight 2.6.21-1.3243.fc8 #1 SMP Sat Jun 30 18:36:29 EDT 2007 i686 i686 i386 GNU/Linux [ramsdell@drawlight audit]$ Testing shows that the bug disappeared with this version of the kernel. Please add my test program to that which is used to perform regression testing for the kernel. (In reply to comment #3) > I just finished setting up a rawhide machine. > > [ramsdell@drawlight audit]$ uname -a > Linux drawlight 2.6.21-1.3243.fc8 #1 SMP Sat Jun 30 18:36:29 EDT 2007 i686 i686 > Testing shows that the bug disappeared with this version of the kernel. > > Please add my test program to that which is used to perform regression testing > for the kernel. If the bug is fixed in rawhide then it's probably also fixed in the 1.3241.fc7 kernel as well, since they have the same utrace patches now. Patches went into kernel 2.6.21-1.3255.fc7 Yum update on my Fedora 7 machine provided me with kernel 2.6.22.1-27.fc7. This kernel does not exhibit the bug, so the utrace patches must have fixed my problem too. Thanks all. |
Description of problem: I wrote a program that uses ptrace to obtain the pid of each forked child before the child starts running. It is used to perform system call tracing while following forks using the audit system similar to "strace -f". The program was working correctly in October of 2006 on an up-to-date Fedora Core 6 system. On Fedora 7, children that never fork die unexpectedly. These children stop twice with SIGSTOP, and by the second time they are continued, they disappear. Version-Release number of selected component (if applicable): Linux goo 2.6.21-1.3228.fc7 #1 SMP Tue Jun 12 15:37:31 EDT 2007 i686 i686 i386 GNU/Linux How reproducible: Use enclosed test program Steps to Reproduce: 1. make ptracefork 2. ./ptracefork 3. Actual results: [ramsdell@goo ~]$ uname -a Linux goo 2.6.21-1.3228.fc7 #1 SMP Tue Jun 12 15:37:31 EDT 2007 i686 i686 i386 GNU/Linux [ramsdell@goo ~]$ ./ptracefork Child is 29160 Wait status for 29160 is 1407 (0x57f) Process 29160 stopped with signal = 5 Set options on 29160 due to SIGTRAP without a child Wait status for 29160 is 66943 (0x1057f) Process 29160 stopped with signal = 5 Process 29160 forked 29161 Wait status for 29161 is 4991 (0x137f) Process 29161 stopped with signal = 19 Wait status for 29160 is 66943 (0x1057f) Process 29160 stopped with signal = 5 Process 29160 forked 29162 Wait status for 29162 is 4991 (0x137f) Process 29162 stopped with signal = 19 Wait status for 29161 is 4991 (0x137f) Process 29161 stopped with signal = 19 ptrace(PTRACE_CONT, ...): No such process [ramsdell@goo ~]$ Expected results: bash-3.2$ make ptracefork cc ptracefork.c -o ptracefork bash-3.2$ uname -a Linux oolong 2.4.21-47.0.1.ELsmp #1 SMP Fri Oct 13 17:56:20 EDT 2006 i686 i686 i386 GNU/Linux bash-3.2$ ./ptracefork Child is 20502 Wait status for 20502 is 1407 (0x57f) Process 20502 stopped with signal = 5 Set options on 20502 due to SIGTRAP without a child Wait status for 20502 is 4991 (0x137f) Process 20502 stopped with signal = 19 Wait status for 20502 is 66943 (0x1057f) Process 20502 stopped with signal = 5 Process 20502 forked 20503 Wait status for 20503 is 4991 (0x137f) Process 20503 stopped with signal = 19 Wait status for 20502 is 66943 (0x1057f) Process 20502 stopped with signal = 5 Process 20502 forked 20504 Wait status for 20503 is 4991 (0x137f) Process 20503 stopped with signal = 19 Wait status for 20503 is 0 (0x0) Wait status for 20504 is 4991 (0x137f) Process 20504 stopped with signal = 19 Wait status for 20504 is 4991 (0x137f) Process 20504 stopped with signal = 19 Wait status for 20504 is 1407 (0x57f) Process 20504 stopped with signal = 5 Process 20504 forked 20503 Wait status for 20504 is 4991 (0x137f) Process 20504 stopped with signal = 19 1 1 4 Wait status for 20504 is 0 (0x0) Wait status for 20502 is 4479 (0x117f) Process 20502 stopped with signal = 17 Wait status for 20502 is 0 (0x0) bash-3.2$ Additional info: