[PATCH kernel v3] zstd: Fixing mixed module-builtin objects

Alexey Kardashevskiy posted 1 patch 3 years, 2 months ago
lib/zstd/Makefile                | 18 ++++++++----------
lib/zstd/common/entropy_common.c |  5 ++++-
lib/zstd/common/zstd_common.c    | 10 ++++++++++
lib/Kconfig                      |  8 ++++++--
4 files changed, 28 insertions(+), 13 deletions(-)
[PATCH kernel v3] zstd: Fixing mixed module-builtin objects
Posted by Alexey Kardashevskiy 3 years, 2 months ago
With CONFIG_ZSTD_COMPRESS=m and CONFIG_ZSTD_DECOMPRESS=y we end up in
a situation when files from lib/zstd/common/ are compiled once to be
linked later for ZSTD_DECOMPRESS (build-in) and ZSTD_COMPRESS (module)
even though CFLAGS are different for builtins and modules.
So far somehow this was not a problem but enabling LLVM LTO exposes
the problem as:

ld.lld: error: linking module flags 'Code Model': IDs have conflicting values in 'lib/built-in.a(zstd_common.o at 5868)' and 'ld-temp.o'

This particular conflict is caused by KBUILD_CFLAGS=-mcmodel=medium vs.
KBUILD_CFLAGS_MODULE=-mcmodel=large , modules use the large model on
POWERPC as explained at
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/Makefile?h=v5.18-rc4#n127
but the current use of common files is wrong anyway.

This works around the issue by introducing a zstd_common module with
shared code.

Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[robot found a problem in v2]
Reported-by: kernel test robot <lkp@intel.com>
---
Changes:
v3:
* added EXPORT_SYMBOL_GPL to compile with:
CONFIG_ZSTD_COMMON=m
CONFIG_ZSTD_COMPRESS=m
CONFIG_ZSTD_DECOMPRESS=m
Vast majority of cases have CONFIG_ZSTD_COMMON=y so this went unnoticed
---
 lib/zstd/Makefile                | 18 ++++++++----------
 lib/zstd/common/entropy_common.c |  5 ++++-
 lib/zstd/common/zstd_common.c    | 10 ++++++++++
 lib/Kconfig                      |  8 ++++++--
 4 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/lib/zstd/Makefile b/lib/zstd/Makefile
index fc45339fc3a3..440bd0007ae2 100644
--- a/lib/zstd/Makefile
+++ b/lib/zstd/Makefile
@@ -10,14 +10,10 @@
 # ################################################################
 obj-$(CONFIG_ZSTD_COMPRESS) += zstd_compress.o
 obj-$(CONFIG_ZSTD_DECOMPRESS) += zstd_decompress.o
+obj-$(CONFIG_ZSTD_COMMON) += zstd_common.o
 
 zstd_compress-y := \
 		zstd_compress_module.o \
-		common/debug.o \
-		common/entropy_common.o \
-		common/error_private.o \
-		common/fse_decompress.o \
-		common/zstd_common.o \
 		compress/fse_compress.o \
 		compress/hist.o \
 		compress/huf_compress.o \
@@ -33,12 +29,14 @@ zstd_compress-y := \
 
 zstd_decompress-y := \
 		zstd_decompress_module.o \
-		common/debug.o \
-		common/entropy_common.o \
-		common/error_private.o \
-		common/fse_decompress.o \
-		common/zstd_common.o \
 		decompress/huf_decompress.o \
 		decompress/zstd_ddict.o \
 		decompress/zstd_decompress.o \
 		decompress/zstd_decompress_block.o \
+
+zstd_common-y := \
+		common/debug.o \
+		common/entropy_common.o \
+		common/error_private.o \
+		common/fse_decompress.o \
+		common/zstd_common.o \
diff --git a/lib/zstd/common/entropy_common.c b/lib/zstd/common/entropy_common.c
index 53b47a2b52ff..a311808c0d56 100644
--- a/lib/zstd/common/entropy_common.c
+++ b/lib/zstd/common/entropy_common.c
@@ -15,6 +15,7 @@
 /* *************************************
 *  Dependencies
 ***************************************/
+#include <linux/module.h>
 #include "mem.h"
 #include "error_private.h"       /* ERR_*, ERROR */
 #define FSE_STATIC_LINKING_ONLY  /* FSE_MIN_TABLELOG */
@@ -239,7 +240,7 @@ size_t FSE_readNCount(
 {
     return FSE_readNCount_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize, /* bmi2 */ 0);
 }
-
+EXPORT_SYMBOL_GPL(FSE_readNCount);
 
 /*! HUF_readStats() :
     Read compact Huffman tree, saved by HUF_writeCTable().
@@ -255,6 +256,7 @@ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
     U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
     return HUF_readStats_wksp(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* bmi2 */ 0);
 }
+EXPORT_SYMBOL_GPL(HUF_readStats);
 
 FORCE_INLINE_TEMPLATE size_t
 HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
@@ -355,3 +357,4 @@ size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize, U32* rankStats,
     (void)bmi2;
     return HUF_readStats_body_default(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
 }
+EXPORT_SYMBOL_GPL(HUF_readStats_wksp);
diff --git a/lib/zstd/common/zstd_common.c b/lib/zstd/common/zstd_common.c
index 3d7e35b309b5..0f1f63be25d9 100644
--- a/lib/zstd/common/zstd_common.c
+++ b/lib/zstd/common/zstd_common.c
@@ -13,6 +13,7 @@
 /*-*************************************
 *  Dependencies
 ***************************************/
+#include <linux/module.h>
 #define ZSTD_DEPS_NEED_MALLOC
 #include "zstd_deps.h"   /* ZSTD_malloc, ZSTD_calloc, ZSTD_free, ZSTD_memset */
 #include "error_private.h"
@@ -35,14 +36,17 @@ const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }
  *  tells if a return value is an error code
  *  symbol is required for external callers */
 unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
+EXPORT_SYMBOL_GPL(ZSTD_isError);
 
 /*! ZSTD_getErrorName() :
  *  provides error code string from function result (useful for debugging) */
 const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
+EXPORT_SYMBOL_GPL(ZSTD_getErrorName);
 
 /*! ZSTD_getError() :
  *  convert a `size_t` function result into a proper ZSTD_errorCode enum */
 ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }
+EXPORT_SYMBOL_GPL(ZSTD_getErrorCode);
 
 /*! ZSTD_getErrorString() :
  *  provides error code string from enum */
@@ -59,6 +63,7 @@ void* ZSTD_customMalloc(size_t size, ZSTD_customMem customMem)
         return customMem.customAlloc(customMem.opaque, size);
     return ZSTD_malloc(size);
 }
+EXPORT_SYMBOL_GPL(ZSTD_customMalloc);
 
 void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
 {
@@ -71,6 +76,7 @@ void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
     }
     return ZSTD_calloc(1, size);
 }
+EXPORT_SYMBOL_GPL(ZSTD_customCalloc);
 
 void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
 {
@@ -81,3 +87,7 @@ void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
             ZSTD_free(ptr);
     }
 }
+EXPORT_SYMBOL_GPL(ZSTD_customFree);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Zstd Common");
diff --git a/lib/Kconfig b/lib/Kconfig
index dc1ab2ed1dc6..3ea8941ab18d 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -343,12 +343,16 @@ config LZ4HC_COMPRESS
 config LZ4_DECOMPRESS
 	tristate
 
+config ZSTD_COMMON
+	select XXHASH
+	tristate
+
 config ZSTD_COMPRESS
-	select XXHASH
+	select ZSTD_COMMON
 	tristate
 
 config ZSTD_DECOMPRESS
-	select XXHASH
+	select ZSTD_COMMON
 	tristate
 
 source "lib/xz/Kconfig"
-- 
2.37.3
Re: [PATCH kernel v3] zstd: Fixing mixed module-builtin objects
Posted by Masahiro Yamada 3 years, 1 month ago
On Thu, Sep 29, 2022 at 11:08 AM Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>
> With CONFIG_ZSTD_COMPRESS=m and CONFIG_ZSTD_DECOMPRESS=y we end up in
> a situation when files from lib/zstd/common/ are compiled once to be
> linked later for ZSTD_DECOMPRESS (build-in) and ZSTD_COMPRESS (module)
> even though CFLAGS are different for builtins and modules.
> So far somehow this was not a problem but enabling LLVM LTO exposes
> the problem as:
>
> ld.lld: error: linking module flags 'Code Model': IDs have conflicting values in 'lib/built-in.a(zstd_common.o at 5868)' and 'ld-temp.o'
>
> This particular conflict is caused by KBUILD_CFLAGS=-mcmodel=medium vs.
> KBUILD_CFLAGS_MODULE=-mcmodel=large , modules use the large model on
> POWERPC as explained at
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/Makefile?h=v5.18-rc4#n127
> but the current use of common files is wrong anyway.


BTW, how to reproduce this error?

You referred to the arch/powerpc/Makefile,
but ARCH=powerpc cannot enable Clang LTO.
(powerpc does not select ARCH_SUPPORTS_LTO_CLANG).






> This works around the issue by introducing a zstd_common module with
> shared code.
>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> [robot found a problem in v2]
> Reported-by: kernel test robot <lkp@intel.com>
> ---
> Changes:
> v3:
> * added EXPORT_SYMBOL_GPL to compile with:
> CONFIG_ZSTD_COMMON=m
> CONFIG_ZSTD_COMPRESS=m
> CONFIG_ZSTD_DECOMPRESS=m
> Vast majority of cases have CONFIG_ZSTD_COMMON=y so this went unnoticed
> ---
>  lib/zstd/Makefile                | 18 ++++++++----------
>  lib/zstd/common/entropy_common.c |  5 ++++-
>  lib/zstd/common/zstd_common.c    | 10 ++++++++++
>  lib/Kconfig                      |  8 ++++++--
>  4 files changed, 28 insertions(+), 13 deletions(-)
>
> diff --git a/lib/zstd/Makefile b/lib/zstd/Makefile
> index fc45339fc3a3..440bd0007ae2 100644
> --- a/lib/zstd/Makefile
> +++ b/lib/zstd/Makefile
> @@ -10,14 +10,10 @@
>  # ################################################################
>  obj-$(CONFIG_ZSTD_COMPRESS) += zstd_compress.o
>  obj-$(CONFIG_ZSTD_DECOMPRESS) += zstd_decompress.o
> +obj-$(CONFIG_ZSTD_COMMON) += zstd_common.o
>
>  zstd_compress-y := \
>                 zstd_compress_module.o \
> -               common/debug.o \
> -               common/entropy_common.o \
> -               common/error_private.o \
> -               common/fse_decompress.o \
> -               common/zstd_common.o \
>                 compress/fse_compress.o \
>                 compress/hist.o \
>                 compress/huf_compress.o \
> @@ -33,12 +29,14 @@ zstd_compress-y := \
>
>  zstd_decompress-y := \
>                 zstd_decompress_module.o \
> -               common/debug.o \
> -               common/entropy_common.o \
> -               common/error_private.o \
> -               common/fse_decompress.o \
> -               common/zstd_common.o \
>                 decompress/huf_decompress.o \
>                 decompress/zstd_ddict.o \
>                 decompress/zstd_decompress.o \
>                 decompress/zstd_decompress_block.o \
> +
> +zstd_common-y := \
> +               common/debug.o \
> +               common/entropy_common.o \
> +               common/error_private.o \
> +               common/fse_decompress.o \
> +               common/zstd_common.o \
> diff --git a/lib/zstd/common/entropy_common.c b/lib/zstd/common/entropy_common.c
> index 53b47a2b52ff..a311808c0d56 100644
> --- a/lib/zstd/common/entropy_common.c
> +++ b/lib/zstd/common/entropy_common.c
> @@ -15,6 +15,7 @@
>  /* *************************************
>  *  Dependencies
>  ***************************************/
> +#include <linux/module.h>
>  #include "mem.h"
>  #include "error_private.h"       /* ERR_*, ERROR */
>  #define FSE_STATIC_LINKING_ONLY  /* FSE_MIN_TABLELOG */
> @@ -239,7 +240,7 @@ size_t FSE_readNCount(
>  {
>      return FSE_readNCount_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize, /* bmi2 */ 0);
>  }
> -
> +EXPORT_SYMBOL_GPL(FSE_readNCount);
>
>  /*! HUF_readStats() :
>      Read compact Huffman tree, saved by HUF_writeCTable().
> @@ -255,6 +256,7 @@ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
>      U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
>      return HUF_readStats_wksp(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* bmi2 */ 0);
>  }
> +EXPORT_SYMBOL_GPL(HUF_readStats);
>
>  FORCE_INLINE_TEMPLATE size_t
>  HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
> @@ -355,3 +357,4 @@ size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize, U32* rankStats,
>      (void)bmi2;
>      return HUF_readStats_body_default(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
>  }
> +EXPORT_SYMBOL_GPL(HUF_readStats_wksp);
> diff --git a/lib/zstd/common/zstd_common.c b/lib/zstd/common/zstd_common.c
> index 3d7e35b309b5..0f1f63be25d9 100644
> --- a/lib/zstd/common/zstd_common.c
> +++ b/lib/zstd/common/zstd_common.c
> @@ -13,6 +13,7 @@
>  /*-*************************************
>  *  Dependencies
>  ***************************************/
> +#include <linux/module.h>
>  #define ZSTD_DEPS_NEED_MALLOC
>  #include "zstd_deps.h"   /* ZSTD_malloc, ZSTD_calloc, ZSTD_free, ZSTD_memset */
>  #include "error_private.h"
> @@ -35,14 +36,17 @@ const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }
>   *  tells if a return value is an error code
>   *  symbol is required for external callers */
>  unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
> +EXPORT_SYMBOL_GPL(ZSTD_isError);
>
>  /*! ZSTD_getErrorName() :
>   *  provides error code string from function result (useful for debugging) */
>  const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
> +EXPORT_SYMBOL_GPL(ZSTD_getErrorName);
>
>  /*! ZSTD_getError() :
>   *  convert a `size_t` function result into a proper ZSTD_errorCode enum */
>  ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }
> +EXPORT_SYMBOL_GPL(ZSTD_getErrorCode);
>
>  /*! ZSTD_getErrorString() :
>   *  provides error code string from enum */
> @@ -59,6 +63,7 @@ void* ZSTD_customMalloc(size_t size, ZSTD_customMem customMem)
>          return customMem.customAlloc(customMem.opaque, size);
>      return ZSTD_malloc(size);
>  }
> +EXPORT_SYMBOL_GPL(ZSTD_customMalloc);
>
>  void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
>  {
> @@ -71,6 +76,7 @@ void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
>      }
>      return ZSTD_calloc(1, size);
>  }
> +EXPORT_SYMBOL_GPL(ZSTD_customCalloc);
>
>  void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
>  {
> @@ -81,3 +87,7 @@ void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
>              ZSTD_free(ptr);
>      }
>  }
> +EXPORT_SYMBOL_GPL(ZSTD_customFree);
> +
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_DESCRIPTION("Zstd Common");
> diff --git a/lib/Kconfig b/lib/Kconfig
> index dc1ab2ed1dc6..3ea8941ab18d 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -343,12 +343,16 @@ config LZ4HC_COMPRESS
>  config LZ4_DECOMPRESS
>         tristate
>
> +config ZSTD_COMMON
> +       select XXHASH
> +       tristate
> +
>  config ZSTD_COMPRESS
> -       select XXHASH
> +       select ZSTD_COMMON
>         tristate
>
>  config ZSTD_DECOMPRESS
> -       select XXHASH
> +       select ZSTD_COMMON
>         tristate
>
>  source "lib/xz/Kconfig"
> --
> 2.37.3
>


-- 
Best Regards
Masahiro Yamada
Re: [PATCH kernel v3] zstd: Fixing mixed module-builtin objects
Posted by Alexey Kardashevskiy 3 years, 1 month ago

On 12/11/2022 07:58, Masahiro Yamada wrote:
> On Thu, Sep 29, 2022 at 11:08 AM Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>>
>> With CONFIG_ZSTD_COMPRESS=m and CONFIG_ZSTD_DECOMPRESS=y we end up in
>> a situation when files from lib/zstd/common/ are compiled once to be
>> linked later for ZSTD_DECOMPRESS (build-in) and ZSTD_COMPRESS (module)
>> even though CFLAGS are different for builtins and modules.
>> So far somehow this was not a problem but enabling LLVM LTO exposes
>> the problem as:
>>
>> ld.lld: error: linking module flags 'Code Model': IDs have conflicting values in 'lib/built-in.a(zstd_common.o at 5868)' and 'ld-temp.o'
>>
>> This particular conflict is caused by KBUILD_CFLAGS=-mcmodel=medium vs.
>> KBUILD_CFLAGS_MODULE=-mcmodel=large , modules use the large model on
>> POWERPC as explained at
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/Makefile?h=v5.18-rc4#n127
>> but the current use of common files is wrong anyway.
> 
> 
> BTW, how to reproduce this error?
> 
> You referred to the arch/powerpc/Makefile,
> but ARCH=powerpc cannot enable Clang LTO.
> (powerpc does not select ARCH_SUPPORTS_LTO_CLANG).


I posted a patch for that a while back but it did not get much interest 
as there appears to be an alternative to LTO which does not require the 
compiler support, I forgot the name of that thing and changed the 
employer since then so lost track of this entirely :)

https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20220629083011.1763768-1-aik@ozlabs.ru/


> 
> 
> 
> 
> 
>> This works around the issue by introducing a zstd_common module with
>> shared code.
>>
>> Cc: Masahiro Yamada <masahiroy@kernel.org>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> [robot found a problem in v2]
>> Reported-by: kernel test robot <lkp@intel.com>
>> ---
>> Changes:
>> v3:
>> * added EXPORT_SYMBOL_GPL to compile with:
>> CONFIG_ZSTD_COMMON=m
>> CONFIG_ZSTD_COMPRESS=m
>> CONFIG_ZSTD_DECOMPRESS=m
>> Vast majority of cases have CONFIG_ZSTD_COMMON=y so this went unnoticed
>> ---
>>   lib/zstd/Makefile                | 18 ++++++++----------
>>   lib/zstd/common/entropy_common.c |  5 ++++-
>>   lib/zstd/common/zstd_common.c    | 10 ++++++++++
>>   lib/Kconfig                      |  8 ++++++--
>>   4 files changed, 28 insertions(+), 13 deletions(-)
>>
>> diff --git a/lib/zstd/Makefile b/lib/zstd/Makefile
>> index fc45339fc3a3..440bd0007ae2 100644
>> --- a/lib/zstd/Makefile
>> +++ b/lib/zstd/Makefile
>> @@ -10,14 +10,10 @@
>>   # ################################################################
>>   obj-$(CONFIG_ZSTD_COMPRESS) += zstd_compress.o
>>   obj-$(CONFIG_ZSTD_DECOMPRESS) += zstd_decompress.o
>> +obj-$(CONFIG_ZSTD_COMMON) += zstd_common.o
>>
>>   zstd_compress-y := \
>>                  zstd_compress_module.o \
>> -               common/debug.o \
>> -               common/entropy_common.o \
>> -               common/error_private.o \
>> -               common/fse_decompress.o \
>> -               common/zstd_common.o \
>>                  compress/fse_compress.o \
>>                  compress/hist.o \
>>                  compress/huf_compress.o \
>> @@ -33,12 +29,14 @@ zstd_compress-y := \
>>
>>   zstd_decompress-y := \
>>                  zstd_decompress_module.o \
>> -               common/debug.o \
>> -               common/entropy_common.o \
>> -               common/error_private.o \
>> -               common/fse_decompress.o \
>> -               common/zstd_common.o \
>>                  decompress/huf_decompress.o \
>>                  decompress/zstd_ddict.o \
>>                  decompress/zstd_decompress.o \
>>                  decompress/zstd_decompress_block.o \
>> +
>> +zstd_common-y := \
>> +               common/debug.o \
>> +               common/entropy_common.o \
>> +               common/error_private.o \
>> +               common/fse_decompress.o \
>> +               common/zstd_common.o \
>> diff --git a/lib/zstd/common/entropy_common.c b/lib/zstd/common/entropy_common.c
>> index 53b47a2b52ff..a311808c0d56 100644
>> --- a/lib/zstd/common/entropy_common.c
>> +++ b/lib/zstd/common/entropy_common.c
>> @@ -15,6 +15,7 @@
>>   /* *************************************
>>   *  Dependencies
>>   ***************************************/
>> +#include <linux/module.h>
>>   #include "mem.h"
>>   #include "error_private.h"       /* ERR_*, ERROR */
>>   #define FSE_STATIC_LINKING_ONLY  /* FSE_MIN_TABLELOG */
>> @@ -239,7 +240,7 @@ size_t FSE_readNCount(
>>   {
>>       return FSE_readNCount_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize, /* bmi2 */ 0);
>>   }
>> -
>> +EXPORT_SYMBOL_GPL(FSE_readNCount);
>>
>>   /*! HUF_readStats() :
>>       Read compact Huffman tree, saved by HUF_writeCTable().
>> @@ -255,6 +256,7 @@ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
>>       U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
>>       return HUF_readStats_wksp(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* bmi2 */ 0);
>>   }
>> +EXPORT_SYMBOL_GPL(HUF_readStats);
>>
>>   FORCE_INLINE_TEMPLATE size_t
>>   HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
>> @@ -355,3 +357,4 @@ size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize, U32* rankStats,
>>       (void)bmi2;
>>       return HUF_readStats_body_default(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
>>   }
>> +EXPORT_SYMBOL_GPL(HUF_readStats_wksp);
>> diff --git a/lib/zstd/common/zstd_common.c b/lib/zstd/common/zstd_common.c
>> index 3d7e35b309b5..0f1f63be25d9 100644
>> --- a/lib/zstd/common/zstd_common.c
>> +++ b/lib/zstd/common/zstd_common.c
>> @@ -13,6 +13,7 @@
>>   /*-*************************************
>>   *  Dependencies
>>   ***************************************/
>> +#include <linux/module.h>
>>   #define ZSTD_DEPS_NEED_MALLOC
>>   #include "zstd_deps.h"   /* ZSTD_malloc, ZSTD_calloc, ZSTD_free, ZSTD_memset */
>>   #include "error_private.h"
>> @@ -35,14 +36,17 @@ const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }
>>    *  tells if a return value is an error code
>>    *  symbol is required for external callers */
>>   unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
>> +EXPORT_SYMBOL_GPL(ZSTD_isError);
>>
>>   /*! ZSTD_getErrorName() :
>>    *  provides error code string from function result (useful for debugging) */
>>   const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
>> +EXPORT_SYMBOL_GPL(ZSTD_getErrorName);
>>
>>   /*! ZSTD_getError() :
>>    *  convert a `size_t` function result into a proper ZSTD_errorCode enum */
>>   ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }
>> +EXPORT_SYMBOL_GPL(ZSTD_getErrorCode);
>>
>>   /*! ZSTD_getErrorString() :
>>    *  provides error code string from enum */
>> @@ -59,6 +63,7 @@ void* ZSTD_customMalloc(size_t size, ZSTD_customMem customMem)
>>           return customMem.customAlloc(customMem.opaque, size);
>>       return ZSTD_malloc(size);
>>   }
>> +EXPORT_SYMBOL_GPL(ZSTD_customMalloc);
>>
>>   void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
>>   {
>> @@ -71,6 +76,7 @@ void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
>>       }
>>       return ZSTD_calloc(1, size);
>>   }
>> +EXPORT_SYMBOL_GPL(ZSTD_customCalloc);
>>
>>   void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
>>   {
>> @@ -81,3 +87,7 @@ void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
>>               ZSTD_free(ptr);
>>       }
>>   }
>> +EXPORT_SYMBOL_GPL(ZSTD_customFree);
>> +
>> +MODULE_LICENSE("Dual BSD/GPL");
>> +MODULE_DESCRIPTION("Zstd Common");
>> diff --git a/lib/Kconfig b/lib/Kconfig
>> index dc1ab2ed1dc6..3ea8941ab18d 100644
>> --- a/lib/Kconfig
>> +++ b/lib/Kconfig
>> @@ -343,12 +343,16 @@ config LZ4HC_COMPRESS
>>   config LZ4_DECOMPRESS
>>          tristate
>>
>> +config ZSTD_COMMON
>> +       select XXHASH
>> +       tristate
>> +
>>   config ZSTD_COMPRESS
>> -       select XXHASH
>> +       select ZSTD_COMMON
>>          tristate
>>
>>   config ZSTD_DECOMPRESS
>> -       select XXHASH
>> +       select ZSTD_COMMON
>>          tristate
>>
>>   source "lib/xz/Kconfig"
>> --
>> 2.37.3
>>
> 
> 

-- 
Alexey
Re: [PATCH kernel v3] zstd: Fixing mixed module-builtin objects
Posted by Masahiro Yamada 3 years, 2 months ago
On Thu, Sep 29, 2022 at 11:08 AM Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>
> With CONFIG_ZSTD_COMPRESS=m and CONFIG_ZSTD_DECOMPRESS=y we end up in
> a situation when files from lib/zstd/common/ are compiled once to be
> linked later for ZSTD_DECOMPRESS (build-in) and ZSTD_COMPRESS (module)
> even though CFLAGS are different for builtins and modules.
> So far somehow this was not a problem but enabling LLVM LTO exposes
> the problem as:
>
> ld.lld: error: linking module flags 'Code Model': IDs have conflicting values in 'lib/built-in.a(zstd_common.o at 5868)' and 'ld-temp.o'
>
> This particular conflict is caused by KBUILD_CFLAGS=-mcmodel=medium vs.
> KBUILD_CFLAGS_MODULE=-mcmodel=large , modules use the large model on
> POWERPC as explained at
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/Makefile?h=v5.18-rc4#n127
> but the current use of common files is wrong anyway.
>
> This works around the issue by introducing a zstd_common module with
> shared code.
>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> [robot found a problem in v2]
> Reported-by: kernel test robot <lkp@intel.com>
> ---
> Changes:
> v3:
> * added EXPORT_SYMBOL_GPL to compile with:
> CONFIG_ZSTD_COMMON=m
> CONFIG_ZSTD_COMPRESS=m
> CONFIG_ZSTD_DECOMPRESS=m
> Vast majority of cases have CONFIG_ZSTD_COMMON=y so this went unnoticed


Applied to linux-kbuild. Thanks.


> ---
>  lib/zstd/Makefile                | 18 ++++++++----------
>  lib/zstd/common/entropy_common.c |  5 ++++-
>  lib/zstd/common/zstd_common.c    | 10 ++++++++++
>  lib/Kconfig                      |  8 ++++++--
>  4 files changed, 28 insertions(+), 13 deletions(-)
>
> diff --git a/lib/zstd/Makefile b/lib/zstd/Makefile
> index fc45339fc3a3..440bd0007ae2 100644
> --- a/lib/zstd/Makefile
> +++ b/lib/zstd/Makefile
> @@ -10,14 +10,10 @@
>  # ################################################################
>  obj-$(CONFIG_ZSTD_COMPRESS) += zstd_compress.o
>  obj-$(CONFIG_ZSTD_DECOMPRESS) += zstd_decompress.o
> +obj-$(CONFIG_ZSTD_COMMON) += zstd_common.o
>
>  zstd_compress-y := \
>                 zstd_compress_module.o \
> -               common/debug.o \
> -               common/entropy_common.o \
> -               common/error_private.o \
> -               common/fse_decompress.o \
> -               common/zstd_common.o \
>                 compress/fse_compress.o \
>                 compress/hist.o \
>                 compress/huf_compress.o \
> @@ -33,12 +29,14 @@ zstd_compress-y := \
>
>  zstd_decompress-y := \
>                 zstd_decompress_module.o \
> -               common/debug.o \
> -               common/entropy_common.o \
> -               common/error_private.o \
> -               common/fse_decompress.o \
> -               common/zstd_common.o \
>                 decompress/huf_decompress.o \
>                 decompress/zstd_ddict.o \
>                 decompress/zstd_decompress.o \
>                 decompress/zstd_decompress_block.o \
> +
> +zstd_common-y := \
> +               common/debug.o \
> +               common/entropy_common.o \
> +               common/error_private.o \
> +               common/fse_decompress.o \
> +               common/zstd_common.o \
> diff --git a/lib/zstd/common/entropy_common.c b/lib/zstd/common/entropy_common.c
> index 53b47a2b52ff..a311808c0d56 100644
> --- a/lib/zstd/common/entropy_common.c
> +++ b/lib/zstd/common/entropy_common.c
> @@ -15,6 +15,7 @@
>  /* *************************************
>  *  Dependencies
>  ***************************************/
> +#include <linux/module.h>
>  #include "mem.h"
>  #include "error_private.h"       /* ERR_*, ERROR */
>  #define FSE_STATIC_LINKING_ONLY  /* FSE_MIN_TABLELOG */
> @@ -239,7 +240,7 @@ size_t FSE_readNCount(
>  {
>      return FSE_readNCount_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize, /* bmi2 */ 0);
>  }
> -
> +EXPORT_SYMBOL_GPL(FSE_readNCount);
>
>  /*! HUF_readStats() :
>      Read compact Huffman tree, saved by HUF_writeCTable().
> @@ -255,6 +256,7 @@ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
>      U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
>      return HUF_readStats_wksp(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* bmi2 */ 0);
>  }
> +EXPORT_SYMBOL_GPL(HUF_readStats);
>
>  FORCE_INLINE_TEMPLATE size_t
>  HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
> @@ -355,3 +357,4 @@ size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize, U32* rankStats,
>      (void)bmi2;
>      return HUF_readStats_body_default(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
>  }
> +EXPORT_SYMBOL_GPL(HUF_readStats_wksp);
> diff --git a/lib/zstd/common/zstd_common.c b/lib/zstd/common/zstd_common.c
> index 3d7e35b309b5..0f1f63be25d9 100644
> --- a/lib/zstd/common/zstd_common.c
> +++ b/lib/zstd/common/zstd_common.c
> @@ -13,6 +13,7 @@
>  /*-*************************************
>  *  Dependencies
>  ***************************************/
> +#include <linux/module.h>
>  #define ZSTD_DEPS_NEED_MALLOC
>  #include "zstd_deps.h"   /* ZSTD_malloc, ZSTD_calloc, ZSTD_free, ZSTD_memset */
>  #include "error_private.h"
> @@ -35,14 +36,17 @@ const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }
>   *  tells if a return value is an error code
>   *  symbol is required for external callers */
>  unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
> +EXPORT_SYMBOL_GPL(ZSTD_isError);
>
>  /*! ZSTD_getErrorName() :
>   *  provides error code string from function result (useful for debugging) */
>  const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
> +EXPORT_SYMBOL_GPL(ZSTD_getErrorName);
>
>  /*! ZSTD_getError() :
>   *  convert a `size_t` function result into a proper ZSTD_errorCode enum */
>  ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }
> +EXPORT_SYMBOL_GPL(ZSTD_getErrorCode);
>
>  /*! ZSTD_getErrorString() :
>   *  provides error code string from enum */
> @@ -59,6 +63,7 @@ void* ZSTD_customMalloc(size_t size, ZSTD_customMem customMem)
>          return customMem.customAlloc(customMem.opaque, size);
>      return ZSTD_malloc(size);
>  }
> +EXPORT_SYMBOL_GPL(ZSTD_customMalloc);
>
>  void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
>  {
> @@ -71,6 +76,7 @@ void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem)
>      }
>      return ZSTD_calloc(1, size);
>  }
> +EXPORT_SYMBOL_GPL(ZSTD_customCalloc);
>
>  void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
>  {
> @@ -81,3 +87,7 @@ void ZSTD_customFree(void* ptr, ZSTD_customMem customMem)
>              ZSTD_free(ptr);
>      }
>  }
> +EXPORT_SYMBOL_GPL(ZSTD_customFree);
> +
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_DESCRIPTION("Zstd Common");
> diff --git a/lib/Kconfig b/lib/Kconfig
> index dc1ab2ed1dc6..3ea8941ab18d 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -343,12 +343,16 @@ config LZ4HC_COMPRESS
>  config LZ4_DECOMPRESS
>         tristate
>
> +config ZSTD_COMMON
> +       select XXHASH
> +       tristate
> +
>  config ZSTD_COMPRESS
> -       select XXHASH
> +       select ZSTD_COMMON
>         tristate
>
>  config ZSTD_DECOMPRESS
> -       select XXHASH
> +       select ZSTD_COMMON
>         tristate
>
>  source "lib/xz/Kconfig"
> --
> 2.37.3
>


-- 
Best Regards
Masahiro Yamada