Bug 250271
| Summary: | [arm64] Weird pmap bug when using O_WRONLY and mmap with PROT_WRITE | ||||||
|---|---|---|---|---|---|---|---|
| Product: | Base System | Reporter: | Emmanuel Vadot <manu> | ||||
| Component: | arm | Assignee: | freebsd-arm (Nobody) <freebsd-arm> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Only Me | CC: | jah, mikael | ||||
| Priority: | --- | ||||||
| Version: | CURRENT | ||||||
| Hardware: | Any | ||||||
| OS: | Any | ||||||
| Attachments: |
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I don't know if this works, since I don't have arm64 hardware or a qemu instance to test with, but could you try this?
Index: sys/arm64/arm64/trap.c
===================================================================
--- sys/arm64/arm64/trap.c (revision 366629)
+++ sys/arm64/arm64/trap.c (working copy)
@@ -301,7 +301,7 @@
break;
default:
ftype = (esr & ISS_DATA_WnR) == 0 ? VM_PROT_READ :
- VM_PROT_READ | VM_PROT_WRITE;
+ VM_PROT_WRITE;
break;
}
(In reply to Jason A. Harmening from comment #1) Yeah andrew@ send me this exact same patch yesterday and it fixes the issue. Good to know, I'll back off and wait for Andrew to make the fix then. |
Created attachment 218664 [details] repro There is a weird pmap bug that prevent us of opening a file in O_WRONLY and mmap it with PROT_WRITE. mmap success (MAP_FAILED isn't returned) but we receive sigsegv with SEGV_ACCERR as the code. This was found in pkg (See PR 250059). Attached is a small program to reproduce the bug, it works on all other platform for what I could see. This mimic what pkg is doing and could probably be smaller but ... Just create a directory, add file.sample in this directory and put some data in it and run ./prog directory It should copy the content of the 'file.sample' to 'file' but instead segfault.