* [RFC PATCH 1/2] pgo: Update .profraw file format to version 7
[not found] <20211123012138.160532-1-jarmo.tiitto@gmail.com>
@ 2021-11-23 1:21 ` Jarmo Tiitto
2021-11-23 1:21 ` [RFC PATCH 2/2] pgo: Make module.lds.S linker script to merge __llvm_prf_ sections Jarmo Tiitto
1 sibling, 0 replies; 3+ messages in thread
From: Jarmo Tiitto @ 2021-11-23 1:21 UTC (permalink / raw)
To: Kees Cook, Nathan Chancellor, Nick Desaulniers,
clang-built-linux, Sami Tolvanen, Bill Wendling, linux-kernel
Cc: Jarmo Tiitto, Joe Perches
Recent LLVM-13 can't read the version 5 profile file any more
so update the format to .profraw file version 7.
This version adds binary_ids_size entry to struct llvm_prf_header
and it is output as zero.
This is enough to fix processing the profile data on LLVM-13 tools.
Signed-off-by: Jarmo Tiitto <jarmo.tiitto@gmail.com>
---
kernel/pgo/fs.c | 1 +
kernel/pgo/pgo.h | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/pgo/fs.c b/kernel/pgo/fs.c
index 3c5aa7c2a4ce..77d23f869503 100644
--- a/kernel/pgo/fs.c
+++ b/kernel/pgo/fs.c
@@ -62,6 +62,7 @@ static void prf_fill_header(void **buffer)
#endif
header->version = LLVM_VARIANT_MASK_IR_PROF | LLVM_INSTR_PROF_RAW_VERSION;
header->data_size = prf_data_count();
+ header->binary_ids_size = 0;
header->padding_bytes_before_counters = 0;
header->counters_size = prf_cnts_count();
header->padding_bytes_after_counters = 0;
diff --git a/kernel/pgo/pgo.h b/kernel/pgo/pgo.h
index 04fbf3bcde1e..45eeff9ab6c4 100644
--- a/kernel/pgo/pgo.h
+++ b/kernel/pgo/pgo.h
@@ -43,7 +43,7 @@
(u64)'R' << 8 | \
(u64)129)
-#define LLVM_INSTR_PROF_RAW_VERSION 5
+#define LLVM_INSTR_PROF_RAW_VERSION 7
#define LLVM_INSTR_PROF_DATA_ALIGNMENT 8
#define LLVM_INSTR_PROF_IPVK_FIRST 0
#define LLVM_INSTR_PROF_IPVK_LAST 1
@@ -56,6 +56,7 @@
* struct llvm_prf_header - represents the raw profile header data structure.
* @magic: the magic token for the file format.
* @version: the version of the file format.
+ * @binary_ids_size: the number of binary ids. (since LLVM_INSTR_PROF_RAW_VERSION >= 7)
* @data_size: the number of entries in the profile data section.
* @padding_bytes_before_counters: the number of padding bytes before the
* counters.
@@ -72,6 +73,7 @@
struct llvm_prf_header {
u64 magic;
u64 version;
+ u64 binary_ids_size;
u64 data_size;
u64 padding_bytes_before_counters;
u64 counters_size;
--
2.34.0
^ permalink raw reply [flat|nested] 3+ messages in thread* [RFC PATCH 2/2] pgo: Make module.lds.S linker script to merge __llvm_prf_ sections.
[not found] <20211123012138.160532-1-jarmo.tiitto@gmail.com>
2021-11-23 1:21 ` [RFC PATCH 1/2] pgo: Update .profraw file format to version 7 Jarmo Tiitto
@ 2021-11-23 1:21 ` Jarmo Tiitto
1 sibling, 0 replies; 3+ messages in thread
From: Jarmo Tiitto @ 2021-11-23 1:21 UTC (permalink / raw)
To: Kees Cook, Nathan Chancellor, Nick Desaulniers,
clang-built-linux, Jessica Yu, Sami Tolvanen, Emil Velikov,
Miroslav Benes, Jarmo Tiitto, Sean Christopherson, linux-kernel
Cc: Bill Wendling, Joe Perches
The compiler leaves many duplicate instances of __llvm_prf_* sections
in final module objects and they confuse the kernel module loader.
Fix this by providing module.lds.S linker script that merges the split
sections like vmlinux.lds.S currently does.
Signed-off-by: Jarmo Tiitto <jarmo.tiitto@gmail.com>
---
I'm not sure the linker script is entirely correct and
it propably needs more work.
---
scripts/module.lds.S | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 04c5685c25cf..83ca5825c0c3 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -60,6 +60,39 @@ SECTIONS {
*(.text .text.[0-9a-zA-Z_]* .text..L.cfi*)
}
#endif
+#ifdef CONFIG_PGO_CLANG
+ /*
+ * With CONFIG_PGO_CLANG the compiler may split __llvm_prf_xxx
+ * objects into multiple sections. Merge them in final .ko object.
+ * However leave .rela__llvm_prf_data sections as-is
+ * since they are needed by the module loader.
+ */
+ __llvm_prf_data : AT(ADDR(__llvm_prf_data)) {
+ __llvm_prf_data_start = .;
+ KEEP(*(SORT(__llvm_prf_data)))
+ __llvm_prf_data_end = .;
+ }
+ __llvm_prf_cnts : AT(ADDR(__llvm_prf_cnts)) {
+ __llvm_prf_cnts_start = .;
+ KEEP(*(SORT(__llvm_prf_cnts)))
+ __llvm_prf_cnts_end = .;
+ }
+ __llvm_prf_names : AT(ADDR(__llvm_prf_names)) {
+ __llvm_prf_names_start = .;
+ KEEP(*(SORT(__llvm_prf_names)))
+ __llvm_prf_names_end = .;
+ }
+ __llvm_prf_vals : AT(ADDR(__llvm_prf_vals)) {
+ __llvm_prf_vals_start = .;
+ KEEP(*(SORT(__llvm_prf_vals)))
+ __llvm_prf_vals_end = .;
+ }
+ __llvm_prf_vnds : AT(ADDR(__llvm_prf_vnds)) {
+ __llvm_prf_vnds_start = .;
+ KEEP(*(SORT(__llvm_prf_vnds)))
+ __llvm_prf_vnds_end = .;
+ }
+#endif
}
/* bring in arch-specific sections */
--
2.34.0
^ permalink raw reply [flat|nested] 3+ messages in thread