[Crash-utility] [PATCH] remove struct zspage_5_17 and use union to resolve issue

[Guanyou Chen <chenguanyou9338@xxxxxxxxx>]

Hi LianBo

We don't need struct zspage_5_17.

---
 defs.h     | 32 +++++++++++++++-----------------
 diskdump.c | 15 ++++++---------
 2 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/defs.h b/defs.h
index 3cb8e63..01f316e 100644
--- a/defs.h
+++ b/defs.h
@@ -7407,28 +7407,26 @@ ulong try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulon
 #define SECTORS_PER_PAGE        (1 << SECTORS_PER_PAGE_SHIFT)

 struct zspage {
-    struct {
-        unsigned int fullness : 2;
-        unsigned int class : 9;
-        unsigned int isolated : 3;
-        unsigned int magic : 8;
+    union {
+        unsigned int flag_bits;
+        struct {
+            unsigned int fullness : 2;
+            unsigned int class : 9;
+            unsigned int isolated : 3;
+            unsigned int magic : 8;
+        } v0;
+        struct {
+            unsigned int huge : 1;
+            unsigned int fullness : 2;
+            unsigned int class : 9;
+            unsigned int isolated : 3;
+            unsigned int magic : 8;
+        } v5_17;
     };
     unsigned int inuse;
     unsigned int freeobj;
 };

-struct zspage_5_17 {
-   struct {
-       unsigned int huge : 1;
-       unsigned int fullness : 2;
-       unsigned int class : 9;
-       unsigned int isolated : 3;
-       unsigned int magic : 8;
-   };
-   unsigned int inuse;
-   unsigned int freeobj;
-};
-

 /*
  * makedumpfile.c
  */
diff --git a/diskdump.c b/diskdump.c
index 3ae7bf2..a928a0e 100644
--- a/diskdump.c
+++ b/diskdump.c
@@ -2819,7 +2819,6 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
 {
    ulong obj, off, class, page, zspage;
    struct zspage zspage_s;
-   struct zspage_5_17 zspage_5_17_s;
    physaddr_t paddr;
    unsigned int obj_idx, class_idx, size;
    ulong pages[2], sizes[2];
@@ -2833,15 +2832,13 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
    readmem(page + OFFSET(page_private), KVADDR, &zspage,
            sizeof(void *), "page_private", FAULT_ON_ERROR);

+    readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);
    if (VALID_MEMBER(zspage_huge)) {
-       readmem(zspage, KVADDR, &zspage_5_17_s,
-           sizeof(struct zspage_5_17), "zspage_5_17", FAULT_ON_ERROR);
-       class_idx = zspage_5_17_s.class;
-       zs_magic = zspage_5_17_s.magic;
+       class_idx = zspage_s.v5_17.class;
+       zs_magic = zspage_s.v5_17.magic;
    } else {
-       readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);
-       class_idx = zspage_s.class;
-       zs_magic = zspage_s.magic;
+       class_idx = zspage_s.v0.class;
+       zs_magic = zspage_s.v0.magic;
    }

    if (zs_magic != ZSPAGE_MAGIC)
@@ -2887,7 +2884,7 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)

 out:
    if (VALID_MEMBER(zspage_huge)) {
-       if (!zspage_5_17_s.huge)
+       if (!zspage_s.v5_17.huge)
            return (zram_buf + ZS_HANDLE_SIZE);
    } else {
        readmem(page, KVADDR, &obj, sizeof(void *), "page flags", FAULT_ON_ERROR);
--
2.39.0

From a4c3fd1deb398b77b5d9ad482cf615377fd676b9 Mon Sep 17 00:00:00 2001
From: chenguanyou <chenguanyou@xxxxxxxxxx>
Date: Wed, 24 Apr 2024 17:00:20 +0800
Subject: [PATCH] remove struct zspage_5_17 and use union to resolve issue

Signed-off-by: chenguanyou <chenguanyou@xxxxxxxxxx>
---
 defs.h     | 32 +++++++++++++++-----------------
 diskdump.c | 15 ++++++---------
 2 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/defs.h b/defs.h
index 3cb8e63..01f316e 100644
--- a/defs.h
+++ b/defs.h
@@ -7407,28 +7407,26 @@ ulong try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulon
 #define SECTORS_PER_PAGE        (1 << SECTORS_PER_PAGE_SHIFT)
 
 struct zspage {
-    struct {
-        unsigned int fullness : 2;
-        unsigned int class : 9;
-        unsigned int isolated : 3;
-        unsigned int magic : 8;
+    union {
+        unsigned int flag_bits;
+        struct {
+            unsigned int fullness : 2;
+            unsigned int class : 9;
+            unsigned int isolated : 3;
+            unsigned int magic : 8;
+        } v0;
+        struct {
+            unsigned int huge : 1;
+            unsigned int fullness : 2;
+            unsigned int class : 9;
+            unsigned int isolated : 3;
+            unsigned int magic : 8;
+        } v5_17;
     };
     unsigned int inuse;
     unsigned int freeobj;
 };
 
-struct zspage_5_17 {
-	struct {
-		unsigned int huge : 1;
-		unsigned int fullness : 2;
-		unsigned int class : 9;
-		unsigned int isolated : 3;
-		unsigned int magic : 8;
-	};
-	unsigned int inuse;
-	unsigned int freeobj;
-};
-
 /*
  * makedumpfile.c
  */
diff --git a/diskdump.c b/diskdump.c
index 3ae7bf2..a928a0e 100644
--- a/diskdump.c
+++ b/diskdump.c
@@ -2819,7 +2819,6 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
 {
 	ulong obj, off, class, page, zspage;
 	struct zspage zspage_s;
-	struct zspage_5_17 zspage_5_17_s;
 	physaddr_t paddr;
 	unsigned int obj_idx, class_idx, size;
 	ulong pages[2], sizes[2];
@@ -2833,15 +2832,13 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
 	readmem(page + OFFSET(page_private), KVADDR, &zspage,
 			sizeof(void *), "page_private", FAULT_ON_ERROR);
 
+    readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);
 	if (VALID_MEMBER(zspage_huge)) {
-		readmem(zspage, KVADDR, &zspage_5_17_s,
-			sizeof(struct zspage_5_17), "zspage_5_17", FAULT_ON_ERROR);
-		class_idx = zspage_5_17_s.class;
-		zs_magic = zspage_5_17_s.magic;
+		class_idx = zspage_s.v5_17.class;
+		zs_magic = zspage_s.v5_17.magic;
 	} else {
-		readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);
-		class_idx = zspage_s.class;
-		zs_magic = zspage_s.magic;
+		class_idx = zspage_s.v0.class;
+		zs_magic = zspage_s.v0.magic;
 	}
 
 	if (zs_magic != ZSPAGE_MAGIC)
@@ -2887,7 +2884,7 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
 
 out:
 	if (VALID_MEMBER(zspage_huge)) {
-		if (!zspage_5_17_s.huge)
+		if (!zspage_s.v5_17.huge)
 			return (zram_buf + ZS_HANDLE_SIZE);
 	} else {
 		readmem(page, KVADDR, &obj, sizeof(void *), "page flags", FAULT_ON_ERROR);
-- 
2.39.0

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