From: Giuliano Procida <gprocida@google.com>
To: libabigail@sourceware.org
Cc: dodji@seketeli.org, kernel-team@android.com, gprocida@google.com,
maennich@google.com, sidnayyar@google.com, vvvvvv@google.com
Subject: [PATCH v2] Narrow Linux symbol CRCs to 32 bits
Date: Fri, 11 Nov 2022 13:21:51 +0000 [thread overview]
Message-ID: <20221111132151.798754-1-gprocida@google.com> (raw)
In-Reply-To: <20221027140928.1480353-1-gprocida@google.com>
MODVERSIONS CRCs are 32-bit hashes of strings representing C type
elements or typed symbols. The hashes are calculated using a 32-bit
CRC, hence the name. The kernel module loading code (implicitly)
truncates any provided CRC value to 32 bits before comparing it with
anything.
When support was added to libabigail, values up to 64 bits wide were
supported. This change narrows libabigail's concept of Linux CRC to 32
bits. No tests are affected.
* include/abg-ir.h (elf_symbol::elf_symbol): Change CRC type
from optional<uint64_t> to optional<uint32_t>.
(elf_symbol::create): Likewise.
(elf_symbol::get_crc): Likewise.
(elf_symbol::set_crc): Likewise.
* src/abg-ir.cc (elf_symbol::priv) Change CRC type from
optional<uint64_t> to optional<uint32_t>.
(elf_symbol::priv::priv): Likewise.
(elf_symbol::elf_symbol): Likewise.
(elf_symbol::create): Likewise.
(elf_symbol::get_crc): Likewise.
(elf_symbol::set_crc): Likewise.
* src/abg-reporter-priv.cc (maybe_report_diff_for_symbol):
Change CRC type from optional<uint64_t> to
optional<uint32_t>.
* src/abg-symtab-reader.cc (symtab::load_): Change crc_values
value type from uint64_t to uint32_t.
Signed-off-by: Giuliano Procida <gprocida@google.com>
---
include/abg-ir.h | 8 ++++----
src/abg-ir.cc | 12 ++++++------
src/abg-reporter-priv.cc | 4 ++--
src/abg-symtab-reader.cc | 2 +-
4 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/include/abg-ir.h b/include/abg-ir.h
index 4892f0e2..546603f4 100644
--- a/include/abg-ir.h
+++ b/include/abg-ir.h
@@ -940,7 +940,7 @@ private:
const version& ve,
visibility vi,
bool is_in_ksymtab = false,
- const abg_compat::optional<uint64_t>& crc = {},
+ const abg_compat::optional<uint32_t>& crc = {},
const abg_compat::optional<std::string>& ns = {},
bool is_suppressed = false);
@@ -966,7 +966,7 @@ public:
const version& ve,
visibility vi,
bool is_in_ksymtab = false,
- const abg_compat::optional<uint64_t>& crc = {},
+ const abg_compat::optional<uint32_t>& crc = {},
const abg_compat::optional<std::string>& ns = {},
bool is_suppressed = false);
@@ -1039,11 +1039,11 @@ public:
void
set_is_in_ksymtab(bool is_in_ksymtab);
- const abg_compat::optional<uint64_t>&
+ const abg_compat::optional<uint32_t>&
get_crc() const;
void
- set_crc(const abg_compat::optional<uint64_t>& crc);
+ set_crc(const abg_compat::optional<uint32_t>& crc);
const abg_compat::optional<std::string>&
get_namespace() const;
diff --git a/src/abg-ir.cc b/src/abg-ir.cc
index 5193934a..a043a532 100644
--- a/src/abg-ir.cc
+++ b/src/abg-ir.cc
@@ -1788,7 +1788,7 @@ struct elf_symbol::priv
// STT_COMMON definition of that name that has the largest size.
bool is_common_;
bool is_in_ksymtab_;
- abg_compat::optional<uint64_t> crc_;
+ abg_compat::optional<uint32_t> crc_;
abg_compat::optional<std::string> namespace_;
bool is_suppressed_;
elf_symbol_wptr main_symbol_;
@@ -1822,7 +1822,7 @@ struct elf_symbol::priv
const elf_symbol::version& ve,
elf_symbol::visibility vi,
bool is_in_ksymtab,
- const abg_compat::optional<uint64_t>& crc,
+ const abg_compat::optional<uint32_t>& crc,
const abg_compat::optional<std::string>& ns,
bool is_suppressed)
: env_(e),
@@ -1896,7 +1896,7 @@ elf_symbol::elf_symbol(const environment* e,
const version& ve,
visibility vi,
bool is_in_ksymtab,
- const abg_compat::optional<uint64_t>& crc,
+ const abg_compat::optional<uint32_t>& crc,
const abg_compat::optional<std::string>& ns,
bool is_suppressed)
: priv_(new priv(e,
@@ -1971,7 +1971,7 @@ elf_symbol::create(const environment* e,
const version& ve,
visibility vi,
bool is_in_ksymtab,
- const abg_compat::optional<uint64_t>& crc,
+ const abg_compat::optional<uint32_t>& crc,
const abg_compat::optional<std::string>& ns,
bool is_suppressed)
{
@@ -2208,7 +2208,7 @@ elf_symbol::set_is_in_ksymtab(bool is_in_ksymtab)
/// Getter of the 'crc' property.
///
/// @return the CRC (modversions) value for Linux Kernel symbols, if any
-const abg_compat::optional<uint64_t>&
+const abg_compat::optional<uint32_t>&
elf_symbol::get_crc() const
{return priv_->crc_;}
@@ -2216,7 +2216,7 @@ elf_symbol::get_crc() const
///
/// @param crc the new CRC (modversions) value for Linux Kernel symbols
void
-elf_symbol::set_crc(const abg_compat::optional<uint64_t>& crc)
+elf_symbol::set_crc(const abg_compat::optional<uint32_t>& crc)
{priv_->crc_ = crc;}
/// Getter of the 'namespace' property.
diff --git a/src/abg-reporter-priv.cc b/src/abg-reporter-priv.cc
index 2ecf8016..70839085 100644
--- a/src/abg-reporter-priv.cc
+++ b/src/abg-reporter-priv.cc
@@ -1149,8 +1149,8 @@ maybe_report_diff_for_symbol(const elf_symbol_sptr& symbol1,
<< "\n";
}
- const abg_compat::optional<uint64_t>& crc1 = symbol1->get_crc();
- const abg_compat::optional<uint64_t>& crc2 = symbol2->get_crc();
+ const abg_compat::optional<uint32_t>& crc1 = symbol1->get_crc();
+ const abg_compat::optional<uint32_t>& crc2 = symbol2->get_crc();
if (crc1 != crc2)
{
const std::string none = "(none)";
diff --git a/src/abg-symtab-reader.cc b/src/abg-symtab-reader.cc
index 606c96a2..8a566f8d 100644
--- a/src/abg-symtab-reader.cc
+++ b/src/abg-symtab-reader.cc
@@ -265,7 +265,7 @@ symtab::load_(Elf* elf_handle,
const bool is_kernel = elf_helpers::is_linux_kernel(elf_handle);
std::unordered_set<std::string> exported_kernel_symbols;
- std::unordered_map<std::string, uint64_t> crc_values;
+ std::unordered_map<std::string, uint32_t> crc_values;
std::unordered_map<std::string, std::string> namespaces;
for (size_t i = 0; i < number_syms; ++i)
--
2.38.1.493.g58b659f92b-goog
next prev parent reply other threads:[~2022-11-11 13:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-27 14:09 [PATCH] " Giuliano Procida
2022-10-27 15:53 ` Giuliano Procida
2022-10-28 15:13 ` Dodji Seketeli
2022-10-28 16:08 ` Giuliano Procida
2022-11-17 10:13 ` Dodji Seketeli
2022-11-11 13:21 ` Giuliano Procida [this message]
2022-11-11 15:44 ` [PATCH v2] " Giuliano Procida
2022-11-17 10:10 ` Dodji Seketeli
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