ppc64le - Fix wrong addend value for switch labels #791
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Commit f0518ef ("create-diff-object: fix ppc64le kpatch_replace_sections_syms() bundling assumption"), subtracted sym.st_value for all bundled symbols on ppc64le and GCC6+ irrespective of function or switch label. As a side effect the addend for switch labels were incorrect and call to local function executed TOC setup code. Fallback to the original behaviour of subtracting sym.st_value only for the dynrela. Example of wrong switch label: ------------------------------ 0000000000000008 <register_netdevice>: ... 31c: 05 00 85 2b cmplwi cr7,r5,5 320: 7c 02 9d 41 bgt cr7,59c <register_netdevice+0x594> 324: 00 00 e2 3c addis r7,r2,0 324: R_PPC64_TOC16_HA .toc+0x580 328: 64 17 a5 78 rldicr r5,r5,2,61 32c: 00 00 47 e9 ld r10,0(r7) 32c: R_PPC64_TOC16_LO_DS .toc+0x580 330: aa 2a 2a 7d lwax r9,r10,r5 334: 14 52 29 7d add r9,r9,r10 338: a6 03 29 7d mtctr r9 33c: 20 04 80 4e bctr 340: 44 02 00 00 .long 0x244 344: f0 01 00 00 .long 0x1f0 348: 20 02 00 00 .long 0x220 34c: 38 02 00 00 .long 0x238 350: 2c 02 00 00 .long 0x22c 354: 50 02 00 00 .long 0x250 358: 00 00 00 60 nop Before Patch (.toc section): Offset Info Type Symbol's Value Symbol's Name + Addend ... 0x580 0000008200000026 R_PPC64_ADDR64 0000000000000008 register_netdevice + 338 After Patch (.toc section): Offset Info Type Symbol's Value Symbol's Name + Addend ... 0x580 0000008200000026 R_PPC64_ADDR64 0000000000000008 register_netdevice + 340 Example of localentry addend removed: ------------------------------------ Before Patch (.toc section): Offset Info Type Symbol's Value Symbol's Name + Addend ... 0x48 0000002c00000026 R_PPC64_ADDR64 0000000000000008 cmdline_proc_show + 0 After Patch (.toc section): Offset Info Type Symbol's Value Symbol's Name + Addend ... 0x48 0000002c00000026 R_PPC64_ADDR64 0000000000000008 cmdline_proc_show + 8 Fixes: f0518ef ("create-diff-object: fix ppc64le kpatch_replace_sections_syms() bundling assumption") Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Member
|
👍 |
Contributor
Author
|
Thanks for the review. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Commit f0518ef ("create-diff-object: fix ppc64le kpatch_replace_sections_syms() bundling assumption"), subtractes sym.st_value for all bundled symbols on ppc64le and GCC6+ irrespective
of function or switch label.
As a side effect, the addend for switch labels were incorrect and call to local function executed TOC setup code. Fallback to the original behavior of subtracting sym.st_value only for the dynrela.
Fixes: f0518ef ("create-diff-object: fix ppc64le kpatch_replace_sections_syms() bundling assumption")
Cc: Josh Poimboeuf jpoimboe@redhat.com
Signed-off-by: Kamalesh Babulal kamalesh@linux.vnet.ibm.com