[PATCH 3/6 V2] [pcm_dmix assembly] fix the interface for safety

frederic.recoules at univ-grenoble-alpes.fr frederic.recoules at univ-grenoble-alpes.fr
Wed Apr 29 21:10:36 CEST 2020


From: Frédéric Recoules <frederic.recoules at orange.fr>

- move 'size' and 'old_ebx' in the output section
  since they are clobbered;
- add the "memory" clobber since input pointers
  are dereferenced;
- (minor) add the "cc" clobber since flags are
  clobbered.

Note: produce exactly the same binary output.

Signed-off-by: Frédéric Recoules <frederic.recoules at orange.fr>
---
 src/pcm/pcm_dmix_i386.h   | 45 +++++++++++++++++----------------------
 src/pcm/pcm_dmix_x86_64.h | 27 +++++++++++------------
 2 files changed, 32 insertions(+), 40 deletions(-)

diff --git a/src/pcm/pcm_dmix_i386.h b/src/pcm/pcm_dmix_i386.h
index e816d5e0..3ea0737d 100644
--- a/src/pcm/pcm_dmix_i386.h
+++ b/src/pcm/pcm_dmix_i386.h
@@ -142,12 +142,11 @@ static void MIX_AREAS_16(unsigned int size,
 		"7:"
 		"\tmovl %[old_ebx], %%ebx\n"	/* ebx is GOT pointer (-fPIC) */

-		: /* no output regs */
-		: [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+		: [size] "+m" (size), [old_ebx] "=m" (old_ebx)
+		: [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_ebx] "m" (old_ebx)
-		: "esi", "edi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "esi", "edi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }

@@ -233,12 +232,11 @@ static void MIX_AREAS_16_MMX(unsigned int size,
                 "5:"
 		"\tmovl %[old_ebx], %%ebx\n"	/* ebx is GOT pointer (-fPIC) */

-		: /* no output regs */
-		: [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+	        : [size] "+m" (size), [old_ebx] "=m" (old_ebx)
+		: [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_ebx] "m" (old_ebx)
-		: "esi", "edi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "esi", "edi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }

@@ -347,12 +345,11 @@ static void MIX_AREAS_32(unsigned int size,
 		"6:"
 		"\tmovl %[old_ebx], %%ebx\n"	/* ebx is GOT pointer (-fPIC) */

-		: /* no output regs */
-		: [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+		: [size] "+m" (size), [old_ebx] "=m" (old_ebx)
+		: [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_ebx] "m" (old_ebx)
-		: "esi", "edi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "esi", "edi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }

@@ -454,12 +451,11 @@ static void MIX_AREAS_24(unsigned int size,
 		"6:"
 		"\tmovl %[old_ebx], %%ebx\n"	/* ebx is GOT pointer (-fPIC) */

-		: /* no output regs */
-		: [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+	        : [size] "+m" (size), [old_ebx] "=m" (old_ebx)
+		: [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_ebx] "m" (old_ebx)
-		: "esi", "edi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "esi", "edi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }

@@ -554,11 +550,10 @@ static void MIX_AREAS_24_CMOV(unsigned int size,
 		"6:"
 		"\tmovl %[old_ebx], %%ebx\n"	/* ebx is GOT pointer (-fPIC) */

-		: /* no output regs */
-		: [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+	        : [size] "+m" (size), [old_ebx] "=m" (old_ebx)
+		: [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_ebx] "m" (old_ebx)
-		: "esi", "edi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "esi", "edi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }
diff --git a/src/pcm/pcm_dmix_x86_64.h b/src/pcm/pcm_dmix_x86_64.h
index dc433b35..7f711547 100644
--- a/src/pcm/pcm_dmix_x86_64.h
+++ b/src/pcm/pcm_dmix_x86_64.h
@@ -114,12 +114,11 @@ static void MIX_AREAS_16(unsigned int size,
 		"\temms\n"
 		"\tmovq %[old_rbx], %%rbx\n"

-		: /* no output regs */
-	        : [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+		: [size] "+m" (size), [old_rbx] "=m" (old_rbx)
+	        : [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_rbx] "m" (old_rbx)
-		: "rsi", "rdi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "rsi", "rdi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }

@@ -230,12 +229,11 @@ static void MIX_AREAS_32(unsigned int size,
 		"6:"
 		"\tmovq %[old_rbx], %%rbx\n"

-		: /* no output regs */
-	        : [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+		: [size] "+m" (size), [old_rbx] "=m" (old_rbx)
+	        : [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_rbx] "m" (old_rbx)
-		: "rsi", "rdi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "rsi", "rdi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }

@@ -334,11 +332,10 @@ static void MIX_AREAS_24(unsigned int size,
 		"6:"
 		"\tmovq %[old_rbx], %%rbx\n"

-		: /* no output regs */
-	        : [size] "m" (size),
-		  [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
+		: [size] "+m" (size), [old_rbx] "=m" (old_rbx)
+	        : [dst] "m" (dst), [src] "m" (src), [sum] "m" (sum),
 		  [dst_step] "m" (dst_step),  [src_step] "m" (src_step),
-		  [sum_step] "m" (sum_step), [old_rbx] "m" (old_rbx)
-		: "rsi", "rdi", "edx", "ecx", "eax"
+		  [sum_step] "m" (sum_step)
+		: "rsi", "rdi", "edx", "ecx", "eax", "memory", "cc"
 	);
 }
--
2.17.1


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