Bug 147939
| Summary: | Running executables fails with efault for a driver using map_user_kiobuf | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 3 | Reporter: | satish <ksatishv> |
| Component: | kernel | Assignee: | Ernie Petrides <petrides> |
| Status: | CLOSED NOTABUG | QA Contact: | Brian Brock <bbrock> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 3.0 | CC: | petrides, riel |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i686 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2005-02-26 01:04:52 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: | |||
It looks like the complication is because we are not able to determine if a address is user or kernel. We were using find_vma to determine that and that doesnot work for hugemem. Is there any interface that can be used to determine if a addr is user or kernel.. Hello, Satish. One cannot determine whether a particular address implies user-space or kernel-space. The whole point of the hugemem kernel is that the full 4-GB address space can be used for user-space, implying that some addresses can be used to reference both spaces. Software must keep track of whether any particular address should result in a user-space access. Fair Enough, I used the get_fs() to determine we are called from kernel_read() and that sort of works. Thanks for looking in to this |
From Bugzilla Helper: User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20041001 Firefox/0.10.1 Description of problem: I am running a filesystem module on 2.4.21-20.ELhugemem. The issue is i am not able to run executables in the filesystem and get a EFAULT from map_user_kiobuf. kernel_read passes in a buffer address which the __get_user_pages is not able to map and returns EFAULT. The filesystem just works fine on a non 'hugemem' kernel. Is there any workaround so that the kernel address passed by exec can be mapped for map_user_kiobuf? Version-Release number of selected component (if applicable): 2.4.21-20.ELhugemem How reproducible: Always Steps to Reproduce: 1. run some command with in the driver space 2. 3. Actual Results: fails with 'bad address' Expected Results: should work Additional info: