On 2021-03-25, Nathan Chancellor wrote:

Clang can generate R_RISCV_CALL_PLT relocations to _mcount:

$ llvm-objdump -dr build/riscv/init/main.o | rg mcount 000000000000000e: R_RISCV_CALL_PLT _mcount 000000000000004e: R_RISCV_CALL_PLT _mcount

After this, the __start_mcount_loc section is properly generated and function tracing still works.

R_RISCV_CALL_PLT can replace R_RISCV_CALL in all use cases. R_RISCV_CALL can/may be deprecated: https://github.com/ClangBuiltLinux/linux/issues/1331#issuecomment-802468296

Reviewed-by: Fangrui Song maskray@google.com

Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1331 Signed-off-by: Nathan Chancellor nathan@kernel.org

---

scripts/recordmcount.pl | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl index 867860ea57da..a36df04cfa09 100755 --- a/scripts/recordmcount.pl +++ b/scripts/recordmcount.pl @@ -392,7 +392,7 @@ if ($arch eq "x86_64") { $mcount_regex = "^\s*([0-9a-fA-F]+):.*\s_mcount$"; } elsif ($arch eq "riscv") { $function_regex = "^([0-9a-fA-F]+)\s+<([^.0-9][0-9a-zA-Z_\.]+)>:";

• $mcount_regex = "^\s*([0-9a-fA-F]+):\sR_RISCV_CALL\s_mcount$";

• $mcount_regex = "^\s*([0-9a-fA-F]+):\sR_RISCV_CALL(_PLT)?\s_mcount$"; $type = ".quad"; $alignment = 2;

} elsif ($arch eq "nds32") {

2.31.0

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