x86-64: Hide internal assembly functions

Hide x86-64 internal assembly functions. Before $ nm -D lib/libzstd.so.1 00000000000c23c0 T _HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop 00000000000c23c0 T HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop 00000000000c283d T _HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop 00000000000c283d T HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop $ After $ nm -D lib/libzstd.so.1 $ This fixes issue facebook#2990.
hjl-tools · Jan 11, 2022 · b6c6891 · b6c6891
1 parent 5f2c3d9
commit b6c6891
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Showing 3 changed files with 12 additions and 2 deletions.
diff --git a/lib/common/portability_macros.h b/lib/common/portability_macros.h
@@ -65,6 +65,12 @@
 # endif
 #endif
 
+/* Mark the internal assembly functions as hidden  */
+#ifdef __ELF__
+# define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func
+#else
+# define ZSTD_HIDE_ASM_FUNCTION(func)
+#endif
 
 /* Enable runtime BMI2 dispatch based on the CPU.
  * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default.

diff --git a/lib/decompress/huf_decompress.c b/lib/decompress/huf_decompress.c
@@ -664,7 +664,7 @@ size_t HUF_decompress4X1_usingDTable_internal_default(void* dst, size_t dstSize,
 
 #if ZSTD_ENABLE_ASM_X86_64_BMI2
 
-HUF_ASM_DECL void HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop(HUF_DecompressAsmArgs* args);
+HUF_ASM_DECL void HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop(HUF_DecompressAsmArgs* args) ZSTDLIB_HIDDEN;
 
 static HUF_ASM_X86_64_BMI2_ATTRS
 size_t
@@ -1380,7 +1380,7 @@ size_t HUF_decompress4X2_usingDTable_internal_default(void* dst, size_t dstSize,
 
 #if ZSTD_ENABLE_ASM_X86_64_BMI2
 
-HUF_ASM_DECL void HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop(HUF_DecompressAsmArgs* args);
+HUF_ASM_DECL void HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop(HUF_DecompressAsmArgs* args) ZSTDLIB_HIDDEN;
 
 static HUF_ASM_X86_64_BMI2_ATTRS size_t
 HUF_decompress4X2_usingDTable_internal_bmi2_asm(

diff --git a/lib/decompress/huf_decompress_amd64.S b/lib/decompress/huf_decompress_amd64.S
@@ -91,6 +91,8 @@
 /* Define both _HUF_* & HUF_* symbols because MacOS
  * C symbols are prefixed with '_' & Linux symbols aren't.
  */
+ZSTD_HIDE_ASM_FUNCTION(_HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop)
+ZSTD_HIDE_ASM_FUNCTION(HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop)
 _HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop:
 HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop:
     /* Save all registers - even if they are callee saved for simplicity. */
@@ -346,6 +348,8 @@ HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop:
     pop %rax
     ret
 
+ZSTD_HIDE_ASM_FUNCTION(_HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop)
+ZSTD_HIDE_ASM_FUNCTION(HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop)
 _HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop:
 HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop:
     /* Save all registers - even if they are callee saved for simplicity. */