[Deepin-Kernel-SIG] [linux 6.6-y] [Upstream] objtool: Ignore dangling jump table entries

[opsiff]

Revert "objtool: Ignore dangling jump table entries"

This reverts commit 8a69697.
It has a small context change need to be handle.

Reapply: objtool: Ignore dangling jump table entries

[ Upstream commit 3724062 ]

Clang sometimes leaves dangling unused jump table entries which point to
the end of the function. Ignore them.

Closes: https://lore.kernel.org/20250113235835.vqgvb7cdspksy5dn@jpoimboe
Reported-by: Klaus Kusche [email protected]
Signed-off-by: Josh Poimboeuf [email protected]
Signed-off-by: Peter Zijlstra (Intel) [email protected]
Link: https://lkml.kernel.org/r/ee25c0b7e80113e950bd1d4c208b671d35774ff4.1736891751.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin [email protected]
(cherry picked from commit 5b1c485)
Conflicts:
tools/objtool/check.c
[Handle 765ecc2:("objtool: Handle various symbol types of rodata")]
Signed-off-by: Wentao Guan [email protected]

Summary by Sourcery

Bug Fixes:

• Fixes an issue where clang sometimes leaves dangling unused jump table entries.

[sourcery-ai]

Reviewer's Guide by Sourcery

This pull request addresses an issue where Clang sometimes creates dangling, unused jump table entries that point to the end of a function. The change modifies the objtool to ignore these entries, preventing false positives during code analysis.

Updated class diagram for objtool check

classDiagram
  class objtool_file {
  }
  class instruction {
  }
  class reloc {
    sym
  }
  class symbol {
    sec
  }
  class section {
  }
  class func {
    sec
    offset
    len
  }

  objtool_file -- instruction : contains
  instruction -- reloc : uses
  reloc -- symbol : refers to
  symbol -- section : belongs to
  func -- section : belongs to

  note for reloc "reloc_addend(reloc) is replaced by offset"

Loading

File-Level Changes

Change	Details	Files
Ignore jump table entries that point to the end of the function.	Modified the condition to ignore jump table entries that point to the end of the function.	tools/objtool/check.c

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[deepin-ci-robot]

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[deepin-ci-robot]

deepin pr auto review

关键摘要:

• 代码中的变量offset在函数add_jump_table中未定义，可能导致编译错误。
• 代码中的reloc_addend(reloc)函数调用被替换为offset，但offset变量未在函数参数中定义，这可能是代码逻辑错误。

是否建议立即修改:

• 是

[sourcery-ai]

Hey @opsiff - I've reviewed your changes - here's some feedback:

Overall Comments:

• Consider adding a comment explaining why offset is used instead of reloc_addend(reloc).

Here's what I looked at during the review

• 🟢 General issues: all looks good
• 🟢 Security: all looks good
• 🟢 Testing: all looks good
• 🟢 Complexity: all looks good
• 🟢 Documentation: all looks good

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