kernel/tools/objtool/check.c, branch linux-5.14.y

objtool: Handle __sanitize_cov*() tail calls

2021-11-17T10:03:58Z

[ Upstream commit f56dae88a81fded66adf2bea9922d1d98d1da14f ] Turns out the compilers also generate tail calls to __sanitize_cov*(), make sure to also patch those out in noinstr code. Fixes: 0f1441b44e82 ("objtool: Fix noinstr vs KCOV") Signed-off-by: Peter Zijlstra (Intel) Acked-by: Marco Elver Link: https://lore.kernel.org/r/20210624095147.818783799@infradead.org Signed-off-by: Sasha Levin

x86/xen: Mark cpu_bringup_and_idle() as dead_end_function

2021-11-17T10:03:57Z

[ Upstream commit 9af9dcf11bda3e2c0e24c1acaacb8685ad974e93 ] The asm_cpu_bringup_and_idle() function is required to push the return value on the stack in order to make ORC happy, but the only reason objtool doesn't complain is because of a happy accident. The thing is that asm_cpu_bringup_and_idle() doesn't return, so validate_branch() never terminates and falls through to the next function, which in the normal case is the hypercall_page. And that, as it happens, is 4095 NOPs and a RET. Make asm_cpu_bringup_and_idle() terminate on it's own, by making the function it calls as a dead-end. This way we no longer rely on what code happens to come after. Fixes: c3881eb58d56 ("x86/xen: Make the secondary CPU idle tasks reliable") Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Juergen Gross Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/20210624095147.693801717@infradead.org Signed-off-by: Sasha Levin

objtool: Reflow handle_jump_alt()

2021-05-14T07:00:10Z

Miroslav figured the code flow in handle_jump_alt() was sub-optimal with that goto. Reflow the code to make it clearer. Reported-by: Miroslav Benes Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/YJ00lgslY+IpA/rL@hirez.programming.kicks-ass.net

objtool: Provide stats for jump_labels

2021-05-12T12:54:56Z

Add objtool --stats to count the jump_label sites it encounters. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210506194158.153101906@infradead.org

objtool: Rewrite jump_label instructions

2021-05-12T12:54:56Z

When a jump_entry::key has bit1 set, rewrite the instruction to be a NOP. This allows the compiler/assembler to emit JMP (and thus decide on which encoding to use). Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210506194158.091028792@infradead.org

Merge tag 'objtool-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-04-28T19:53:24Z

Pull objtool updates from Ingo Molnar: - Standardize the crypto asm code so that it looks like compiler- generated code to objtool - so that it can understand it. This enables unwinding from crypto asm code - and also fixes the last known remaining objtool warnings for LTO and more. - x86 decoder fixes: clean up and fix the decoder, and also extend it a bit - Misc fixes and cleanups * tag 'objtool-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/crypto: Enable objtool in crypto code x86/crypto/sha512-ssse3: Standardize stack alignment prologue x86/crypto/sha512-avx2: Standardize stack alignment prologue x86/crypto/sha512-avx: Standardize stack alignment prologue x86/crypto/sha256-avx2: Standardize stack alignment prologue x86/crypto/sha1_avx2: Standardize stack alignment prologue x86/crypto/sha_ni: Standardize stack alignment prologue x86/crypto/crc32c-pcl-intel: Standardize jump table x86/crypto/camellia-aesni-avx2: Unconditionally allocate stack buffer x86/crypto/aesni-intel_avx: Standardize stack alignment prologue x86/crypto/aesni-intel_avx: Fix register usage comments x86/crypto/aesni-intel_avx: Remove unused macros objtool: Support asm jump tables objtool: Parse options from OBJTOOL_ARGS objtool: Collate parse_options() users objtool: Add --backup objtool,x86: More ModRM sugar objtool,x86: Rewrite ADD/SUB/AND objtool,x86: Support %riz encodings objtool,x86: Simplify register decode ...

objtool: Support asm jump tables

2021-04-19T17:36:32Z

Objtool detection of asm jump tables would normally just work, except for the fact that asm retpolines use alternatives. Objtool thinks the alternative code path (a jump to the retpoline) is a sibling call. Don't treat alternative indirect branches as sibling calls when the original instruction has a jump table. Signed-off-by: Josh Poimboeuf Tested-by: Ard Biesheuvel Acked-by: Ard Biesheuvel Tested-by: Sami Tolvanen Acked-by: Peter Zijlstra (Intel) Acked-by: Herbert Xu Link: https://lore.kernel.org/r/460cf4dc675d64e1124146562cabd2c05aa322e8.1614182415.git.jpoimboe@redhat.com

objtool: Cache instruction relocs

2021-04-02T10:46:15Z

Track the reloc of instructions in the new instruction->reloc field to avoid having to look them up again later. ( Technically x86 instructions can have two relocations, but not jumps and calls, for which we're using this. ) Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Signed-off-by: Ingo Molnar Reviewed-by: Miroslav Benes Link: https://lkml.kernel.org/r/20210326151300.195441549@infradead.org

objtool: Keep track of retpoline call sites

2021-04-02T10:45:27Z

Provide infrastructure for architectures to rewrite/augment compiler generated retpoline calls. Similar to what we do for static_call()s, keep track of the instructions that are retpoline calls. Use the same list_head, since a retpoline call cannot also be a static_call. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Signed-off-by: Ingo Molnar Reviewed-by: Miroslav Benes Link: https://lkml.kernel.org/r/20210326151300.130805730@infradead.org

objtool: Create reloc sections implicitly

2021-04-02T10:44:37Z

Have elf_add_reloc() create the relocation section implicitly. Suggested-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Signed-off-by: Ingo Molnar Reviewed-by: Miroslav Benes Link: https://lkml.kernel.org/r/20210326151259.880174448@infradead.org