Date: Fri, 04 Jul 2025 12:50:34 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 288000] [PATCH] dtrace: fix symbol address resolving Message-ID: <bug-288000-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=288000 Bug ID: 288000 Summary: [PATCH] dtrace: fix symbol address resolving Product: Base System Version: CURRENT Hardware: amd64 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: zldrobit@gmail.com Created attachment 261862 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=261862&action=edit file of the patch Dtrace assumes only ELF sections of type SHT_PROGBITS or SHT_NOBITS occupy memory space. However, sections with SHF_ALLOC flag also consume memory space. Moreover, the symbol address initialization skips symbols at the very beginning of a section. Fix: Check section flag for calculating section offset, and disable the skipping at the beginning of a section. Reproduction (requires `zfs.ko` and `ksyms.ko`): 1. readelf -s /dev/ksyms | grep -b '\<zfs_dirty_data_max\>' 2. dtrace -n 'BEGIN {printf("%p", &`zfs_dirty_data_max);}' 3. The symbol addresses are different. Reproduction of the 2nd problem (requires `ossl.ko` and `ksyms.ko`): 1. readelf -s /dev/ksyms | grep -b '\<OPENSSL_ia32cap_P\>' 2. dtrace -n 'BEGIN {printf("%p", &`OPENSSL_ia32cap_P);}' 3. The symbol address of step 2 is zero while that of step 1 is not. The patch is uploaded as an attachment. -- You are receiving this mail because: You are the assignee for the bug.home | help
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