On Wed, Apr 07, 2021 at 11:54:55AM -0700, Nick Desaulniers wrote: > LLVM changed the expected function signature for > llvm_gcda_emit_function() in the clang-11 release. Users of clang-11 or > newer may have noticed their kernels producing invalid coverage > information: > > $ llvm-cov gcov -a -c -u -f -b <input>.gcda -- gcno=<input>.gcno > 1 <func>: checksum mismatch, \ > (<lineno chksum A>, <cfg chksum B>) != (<lineno chksum A>, <cfg chksum C>) > 2 Invalid .gcda File! > ... > > Fix up the function signatures so calling this function interprets its > parameters correctly and computes the correct cfg checksum. In > particular, in clang-11, the additional checksum is no longer optional. > > Link: https://reviews.llvm.org/rG25544ce2df0daa4304c07e64b9c8b0f7df60c11d > Cc: stable@xxxxxxxxxxxxxxx #5.4+ > Reported-by: Prasad Sodagudi <psodagud@xxxxxxxxxxx> > Tested-by: Prasad Sodagudi <psodagud@xxxxxxxxxxx> > Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx> > --- > kernel/gcov/clang.c | 38 +++++++++++++++++++++++++++++++++----- > 1 file changed, 33 insertions(+), 5 deletions(-) > > diff --git a/kernel/gcov/clang.c b/kernel/gcov/clang.c > index d41f5ecda9db..1747204541bf 100644 > --- a/kernel/gcov/clang.c > +++ b/kernel/gcov/clang.c > @@ -69,7 +69,9 @@ struct gcov_fn_info { > > u32 ident; > u32 checksum; > +#if CONFIG_CLANG_VERSION < 110000 > u8 use_extra_checksum; > +#endif > u32 cfg_checksum; > > u32 num_counters; > @@ -111,6 +113,7 @@ void llvm_gcda_start_file(const char *orig_filename, u32 version, u32 checksum) > } > EXPORT_SYMBOL(llvm_gcda_start_file); > > +#if CONFIG_CLANG_VERSION < 110000 > void llvm_gcda_emit_function(u32 ident, u32 func_checksum, > u8 use_extra_checksum, u32 cfg_checksum) > { > @@ -126,6 +129,21 @@ void llvm_gcda_emit_function(u32 ident, u32 func_checksum, > info->cfg_checksum = cfg_checksum; > list_add_tail(&info->head, ¤t_info->functions); > } > +#else > +void llvm_gcda_emit_function(u32 ident, u32 func_checksum, u32 cfg_checksum) > +{ > + struct gcov_fn_info *info = kzalloc(sizeof(*info), GFP_KERNEL); > + > + if (!info) > + return; > + > + INIT_LIST_HEAD(&info->head); > + info->ident = ident; > + info->checksum = func_checksum; > + info->cfg_checksum = cfg_checksum; > + list_add_tail(&info->head, ¤t_info->functions); > +} > +#endif > EXPORT_SYMBOL(llvm_gcda_emit_function); > > void llvm_gcda_emit_arcs(u32 num_counters, u64 *counters) > @@ -256,11 +274,16 @@ int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2) > !list_is_last(&fn_ptr2->head, &info2->functions)) { > if (fn_ptr1->checksum != fn_ptr2->checksum) > return false; > +#if CONFIG_CLANG_VERSION < 110000 > if (fn_ptr1->use_extra_checksum != fn_ptr2->use_extra_checksum) > return false; > if (fn_ptr1->use_extra_checksum && > fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum) > return false; > +#else > + if (fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum) > + return false; > +#endif > fn_ptr1 = list_next_entry(fn_ptr1, head); > fn_ptr2 = list_next_entry(fn_ptr2, head); > } > @@ -378,17 +401,22 @@ size_t convert_to_gcda(char *buffer, struct gcov_info *info) > > list_for_each_entry(fi_ptr, &info->functions, head) { > u32 i; > - u32 len = 2; > - > - if (fi_ptr->use_extra_checksum) > - len++; > > pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION); > - pos += store_gcov_u32(buffer, pos, len); > +#if CONFIG_CLANG_VERSION < 110000 > + pos += store_gcov_u32(buffer, pos, > + fi_ptr->use_extra_checksum ? 3 : 2); > +#else > + pos += store_gcov_u32(buffer, pos, 3); > +#endif > pos += store_gcov_u32(buffer, pos, fi_ptr->ident); > pos += store_gcov_u32(buffer, pos, fi_ptr->checksum); > +#if CONFIG_CLANG_VERSION < 110000 > if (fi_ptr->use_extra_checksum) > pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum); > +#else > + pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum); > +#endif > > pos += store_gcov_u32(buffer, pos, GCOV_TAG_COUNTER_BASE); > pos += store_gcov_u32(buffer, pos, fi_ptr->num_counters * 2); > -- > 2.31.1.295.g9ea45b61b8-goog >
