path: root/sys-cluster/lustre/files/lustre-2.13.0-gcc9.patch

From 1bbd0a24bb072c470d5bd93be2010b86b7a80382 Mon Sep 17 00:00:00 2001
From: James Simmons <jsimmons@infradead.org>
Date: Thu, 21 Nov 2019 14:17:47 -0500
Subject: [PATCH] LU-12822 uapi: properly pack data structures

Linux UAPI headers use the gcc attributre __packed__ to ensure
that the data structures are the exact same size on all platforms.
This comes at the cost of potential misaligned accesses to these
data structures which at best cost performance and at worst cause
a bus error on some platforms. To detect potential misaligned
access starting with gcc version 9 a new compile flags was
introduced which is now impacting builds with Lustre.

Examining the build failures shows most of the problems are due to
packed data structures in the Lustre UAPI header containing
unpacked data structure fields. Packing those missed structures
resolved many of the build issues. The second problem is that the
lustre utilities tend to cast some of its UAPI data structure.
A good example is struct lov_user_md being cast to
struct lov_user_md_v3. To ensure this is properly handled with
packed data structures we need to use the __may_alias__ compiler
attribute. The one exception is struct statx which is defined out
side of Lustre and its unpacked. This requires extra special
handling in user land code due to the described issues in this
comment.

Fixing this problem exposed an incorrect wiretest for
struct update_op

Last problem address is the use of __swabXXp() on packed data
structure fields. Because of the potential alignment issues we
have to use __swabXX() functions instead.

Change-Id: I149c55d3361e893bd890f9c5e9c77c15f81acc1b
Signed-off-by: James Simmons <jsimmons@infradead.org>
---
 lustre/include/uapi/linux/lustre/lustre_idl.h |  6 +--
 .../include/uapi/linux/lustre/lustre_user.h   | 14 +++---
 lustre/ptlrpc/wiretest.c                      |  2 +-
 lustre/utils/liblustreapi.c                   | 50 +++++++++----------
 lustre/utils/liblustreapi_layout.c            | 36 ++++++-------
 5 files changed, 54 insertions(+), 54 deletions(-)

diff --git a/lustre/include/uapi/linux/lustre/lustre_idl.h b/lustre/include/uapi/linux/lustre/lustre_idl.h
index db941b24b1..123d73d339 100644
--- a/lustre/include/uapi/linux/lustre/lustre_idl.h
+++ b/lustre/include/uapi/linux/lustre/lustre_idl.h
@@ -2738,12 +2738,12 @@ struct llog_rec_hdr {
 	__u32	lrh_index;
 	__u32	lrh_type;
 	__u32	lrh_id;
-};
+} __attribute__((packed));
 
 struct llog_rec_tail {
 	__u32	lrt_len;
 	__u32	lrt_index;
-};
+} __attribute__((packed));
 
 /* Where data follow just after header */
 #define REC_DATA(ptr)						\
@@ -3551,7 +3551,7 @@ struct update_op {
 	__u16		uop_type;
 	__u16		uop_param_count;
 	__u16		uop_params_off[0];
-};
+} __attribute__((packed));
 
 struct update_ops {
 	struct update_op	uops_op[0];
diff --git a/lustre/include/uapi/linux/lustre/lustre_user.h b/lustre/include/uapi/linux/lustre/lustre_user.h
index bec8c97880..440854d175 100644
--- a/lustre/include/uapi/linux/lustre/lustre_user.h
+++ b/lustre/include/uapi/linux/lustre/lustre_user.h
@@ -324,7 +324,7 @@ struct lu_fid {
 	 * used.
 	 **/
 	__u32 f_ver;
-};
+} __attribute__((packed));
 
 static inline bool fid_is_zero(const struct lu_fid *fid)
 {
@@ -502,7 +502,7 @@ struct ost_id {
 		} oi;
 		struct lu_fid oi_fid;
 	};
-};
+} __attribute__((packed));
 
 #define DOSTID "%#llx:%llu"
 #define POSTID(oi) ((unsigned long long)ostid_seq(oi)), \
@@ -792,7 +792,7 @@ struct lov_user_md_v3 {           /* LOV EA user data (host-endian) */
 	};
 	char  lmm_pool_name[LOV_MAXPOOLNAME + 1]; /* pool name */
 	struct lov_user_ost_data_v1 lmm_objects[0]; /* per-stripe data */
-} __attribute__((packed));
+} __attribute__((packed, __may_alias__));
 
 struct lov_foreign_md {
 	__u32 lfm_magic;	/* magic number = LOV_MAGIC_FOREIGN */
@@ -800,7 +800,7 @@ struct lov_foreign_md {
 	__u32 lfm_type;		/* type, see LU_FOREIGN_TYPE_ */
 	__u32 lfm_flags;	/* flags, type specific */
 	char lfm_value[];
-};
+} __attribute__((packed));
 
 #define foreign_size(lfm) (((struct lov_foreign_md *)lfm)->lfm_length + \
 			   offsetof(struct lov_foreign_md, lfm_value))
@@ -818,7 +818,7 @@ struct lov_foreign_md {
 struct lu_extent {
 	__u64	e_start;
 	__u64	e_end;
-};
+} __attribute__((packed));
 
 #define DEXT "[%#llx, %#llx)"
 #define PEXT(ext) (unsigned long long)(ext)->e_start, (unsigned long long)(ext)->e_end
@@ -979,7 +979,7 @@ struct lmv_user_mds_data {
 	struct lu_fid	lum_fid;
 	__u32		lum_padding;
 	__u32		lum_mds;
-};
+} __attribute__((packed, __may_alias__));
 
 enum lmv_hash_type {
 	LMV_HASH_TYPE_UNKNOWN	= 0,	/* 0 is reserved for testing purpose */
@@ -1631,7 +1631,7 @@ struct changelog_rec {
 		__u32		cr_markerflags; /**< CL_MARK flags */
 	};
 	struct lu_fid		cr_pfid;        /**< parent fid */
-};
+} __attribute__ ((packed));
 
 /* Changelog extension for RENAME. */
 struct changelog_ext_rename {
diff --git a/lustre/ptlrpc/wiretest.c b/lustre/ptlrpc/wiretest.c
index 3056a0bb7c..c2ce845050 100644
--- a/lustre/ptlrpc/wiretest.c
+++ b/lustre/ptlrpc/wiretest.c
@@ -5444,7 +5444,7 @@ void lustre_assert_wire_constants(void)
 		 (long long)(int)sizeof(((struct update_params *)0)->up_params));
 
 	/* Checks for struct update_op */
-	LASSERTF((int)sizeof(struct update_op) == 24, "found %lld\n",
+	LASSERTF((int)sizeof(struct update_op) == 20, "found %lld\n",
 		 (long long)(int)sizeof(struct update_op));
 	LASSERTF((int)offsetof(struct update_op, uop_fid) == 0, "found %lld\n",
 		 (long long)(int)offsetof(struct update_op, uop_fid));
diff --git a/lustre/utils/liblustreapi.c b/lustre/utils/liblustreapi.c
index 754536f117..0669a876f0 100644
--- a/lustre/utils/liblustreapi.c
+++ b/lustre/utils/liblustreapi.c
@@ -2154,12 +2154,12 @@ static int llapi_semantic_traverse(char *path, int size, DIR *parent,
 		strcat(path, dent->d_name);
 
 		if (dent->d_type == DT_UNKNOWN) {
-			lstatx_t *stx = &param->fp_lmd->lmd_stx;
+			lstatx_t stx = param->fp_lmd->lmd_stx;
 
 			rc = get_lmd_info(path, d, NULL, param->fp_lmd,
 					  param->fp_lum_size, GET_LMD_INFO);
 			if (rc == 0)
-				dent->d_type = IFTODT(stx->stx_mode);
+				dent->d_type = IFTODT(stx.stx_mode);
 			else if (ret == 0)
 				ret = rc;
 
@@ -3985,7 +3985,7 @@ int llapi_file_lookup(int dirfd, const char *name)
  *
  * If 0 is returned, we need to do another RPC to the OSTs to obtain the
  * updated timestamps. */
-static int find_time_check(lstatx_t *stx, struct find_param *param, int mds)
+static int find_time_check(struct statx *stx, struct find_param *param, int mds)
 {
 	int rc = 1;
 	int rc2;
@@ -4039,13 +4039,13 @@ static int check_obd_match(struct find_param *param)
 	struct lov_user_ost_data_v1 *objects;
 	struct lov_comp_md_v1 *comp_v1 = NULL;
 	struct lov_user_md_v1 *v1 = &param->fp_lmd->lmd_lmm;
-	lstatx_t *stx = &param->fp_lmd->lmd_stx;
+	lstatx_t stx = param->fp_lmd->lmd_stx;
 	int i, j, k, count = 1;
 
 	if (param->fp_obd_uuid && param->fp_obd_index == OBD_NOT_FOUND)
 		return 0;
 
-	if (!S_ISREG(stx->stx_mode))
+	if (!S_ISREG(stx.stx_mode))
 		return 0;
 
 	/* exclude foreign */
@@ -4358,7 +4358,7 @@ static int find_check_pool(struct find_param *param)
 
 static int find_check_comp_options(struct find_param *param)
 {
-	lstatx_t *stx = &param->fp_lmd->lmd_stx;
+	lstatx_t stx = param->fp_lmd->lmd_stx;
 	struct lov_comp_md_v1 *comp_v1, *forged_v1 = NULL;
 	struct lov_user_md_v1 *v1 = &param->fp_lmd->lmd_lmm;
 	struct lov_comp_md_entry_v1 *entry;
@@ -4376,7 +4376,7 @@ static int find_check_comp_options(struct find_param *param)
 		comp_v1 = forged_v1;
 		comp_v1->lcm_entry_count = 1;
 		entry = &comp_v1->lcm_entries[0];
-		entry->lcme_flags = S_ISDIR(stx->stx_mode) ? 0 : LCME_FL_INIT;
+		entry->lcme_flags = S_ISDIR(stx.stx_mode) ? 0 : LCME_FL_INIT;
 		entry->lcme_extent.e_start = 0;
 		entry->lcme_extent.e_end = LUSTRE_EOF;
 	}
@@ -4504,7 +4504,7 @@ static int cb_find_init(char *path, DIR *parent, DIR **dirp,
 	struct find_param *param = (struct find_param *)data;
 	DIR *dir = dirp == NULL ? NULL : *dirp;
 	int decision = 1; /* 1 is accepted; -1 is rejected. */
-	lstatx_t *stx = &param->fp_lmd->lmd_stx;
+	struct statx stx = param->fp_lmd->lmd_stx;
 	int lustre_fs = 1;
 	int checked_type = 0;
 	int ret = 0;
@@ -4594,7 +4594,7 @@ static int cb_find_init(char *path, DIR *parent, DIR **dirp,
 			if (dir != NULL) {
 				ret = llapi_file_fget_mdtidx(dirfd(dir),
 						     &param->fp_file_mdt_index);
-			} else if (S_ISREG(stx->stx_mode)) {
+			} else if (S_ISREG(stx.stx_mode)) {
 				/* FIXME: we could get the MDT index from the
 				 * file's FID in lmd->lmd_lmm.lmm_oi without
 				 * opening the file, once we are sure that
@@ -4628,7 +4628,7 @@ static int cb_find_init(char *path, DIR *parent, DIR **dirp,
 	}
 
 	if (param->fp_type && !checked_type) {
-		if ((stx->stx_mode & S_IFMT) == param->fp_type) {
+		if ((stx.stx_mode & S_IFMT) == param->fp_type) {
 			if (param->fp_exclude_type)
 				goto decided;
 		} else {
@@ -4640,8 +4640,8 @@ static int cb_find_init(char *path, DIR *parent, DIR **dirp,
         /* Prepare odb. */
 	if (param->fp_obd_uuid || param->fp_mdt_uuid) {
 		if (lustre_fs && param->fp_got_uuids &&
-		    param->fp_dev != makedev(stx->stx_dev_major,
-					     stx->stx_dev_minor)) {
+		    param->fp_dev != makedev(stx.stx_dev_major,
+					     stx.stx_dev_minor)) {
 			/* A lustre/lustre mount point is crossed. */
 			param->fp_got_uuids = 0;
 			param->fp_obds_printed = 0;
@@ -4655,8 +4655,8 @@ static int cb_find_init(char *path, DIR *parent, DIR **dirp,
 			if (ret)
 				goto out;
 
-			param->fp_dev = makedev(stx->stx_dev_major,
-						stx->stx_dev_minor);
+			param->fp_dev = makedev(stx.stx_dev_major,
+						stx.stx_dev_minor);
 		} else if (!lustre_fs && param->fp_got_uuids) {
 			/* A lustre/non-lustre mount point is crossed. */
 			param->fp_got_uuids = 0;
@@ -4758,7 +4758,7 @@ static int cb_find_init(char *path, DIR *parent, DIR **dirp,
 
 obd_matches:
 	if (param->fp_check_uid) {
-		if (stx->stx_uid == param->fp_uid) {
+		if (stx.stx_uid == param->fp_uid) {
 			if (param->fp_exclude_uid)
 				goto decided;
 		} else {
@@ -4768,7 +4768,7 @@ obd_matches:
 	}
 
 	if (param->fp_check_gid) {
-		if (stx->stx_gid == param->fp_gid) {
+		if (stx.stx_gid == param->fp_gid) {
 			if (param->fp_exclude_gid)
 				goto decided;
 		} else {
@@ -4823,23 +4823,23 @@ obd_matches:
                 int for_mds;
 
 		for_mds = lustre_fs ?
-			(S_ISREG(stx->stx_mode) && stripe_count) : 0;
-		decision = find_time_check(stx, param, for_mds);
+			(S_ISREG(stx.stx_mode) && stripe_count) : 0;
+		decision = find_time_check(&stx, param, for_mds);
 		if (decision == -1)
 			goto decided;
 	}
 
 	flags = param->fp_lmd->lmd_flags;
 	if (param->fp_check_size &&
-	    ((S_ISREG(stx->stx_mode) && stripe_count) ||
-	      S_ISDIR(stx->stx_mode)) &&
+	    ((S_ISREG(stx.stx_mode) && stripe_count) ||
+	      S_ISDIR(stx.stx_mode)) &&
 	    !(flags & OBD_MD_FLSIZE ||
 	      (param->fp_lazy && flags & OBD_MD_FLLAZYSIZE)))
 		decision = 0;
 
 	if (param->fp_check_blocks &&
-	    ((S_ISREG(stx->stx_mode) && stripe_count) ||
-	      S_ISDIR(stx->stx_mode)) &&
+	    ((S_ISREG(stx.stx_mode) && stripe_count) ||
+	      S_ISDIR(stx.stx_mode)) &&
 	    !(flags & OBD_MD_FLBLOCKS ||
 	      (param->fp_lazy && flags & OBD_MD_FLLAZYBLOCKS)))
 		decision = 0;
@@ -4884,13 +4884,13 @@ obd_matches:
 
 		convert_lmd_statx(param->fp_lmd, &st, true);
 		/* Check the time on osc. */
-		decision = find_time_check(stx, param, 0);
+		decision = find_time_check(&stx, param, 0);
 		if (decision == -1)
 			goto decided;
 	}
 
 	if (param->fp_check_size) {
-		decision = find_value_cmp(stx->stx_size, param->fp_size,
+		decision = find_value_cmp(stx.stx_size, param->fp_size,
 					  param->fp_size_sign,
 					  param->fp_exclude_size,
 					  param->fp_size_units, 0);
@@ -4899,7 +4899,7 @@ obd_matches:
 	}
 
 	if (param->fp_check_blocks) { /* convert st_blocks to bytes */
-		decision = find_value_cmp(stx->stx_blocks * 512,
+		decision = find_value_cmp(stx.stx_blocks * 512,
 					  param->fp_blocks,
 					  param->fp_blocks_sign,
 					  param->fp_exclude_blocks,
diff --git a/lustre/utils/liblustreapi_layout.c b/lustre/utils/liblustreapi_layout.c
index e47b303798..720fae814d 100644
--- a/lustre/utils/liblustreapi_layout.c
+++ b/lustre/utils/liblustreapi_layout.c
@@ -135,11 +135,11 @@ llapi_layout_swab_lov_user_md(struct lov_user_md *lum, int lum_size)
 		comp_v1 = (struct lov_comp_md_v1 *)lum;
 
 	if (comp_v1 != NULL) {
-		__swab32s(&comp_v1->lcm_magic);
-		__swab32s(&comp_v1->lcm_size);
-		__swab32s(&comp_v1->lcm_layout_gen);
-		__swab16s(&comp_v1->lcm_flags);
-		__swab16s(&comp_v1->lcm_entry_count);
+		comp_v1->lcm_magic = __swab32(comp_v1->lcm_magic);
+		comp_v1->lcm_size = __swab32(comp_v1->lcm_size);
+		comp_v1->lcm_layout_gen = __swab32(comp_v1->lcm_layout_gen);
+		comp_v1->lcm_flags = __swab16(comp_v1->lcm_flags);
+		comp_v1->lcm_entry_count = __swab16(comp_v1->lcm_entry_count);
 		ent_count = comp_v1->lcm_entry_count;
 	} else {
 		ent_count = 1;
@@ -148,13 +148,13 @@ llapi_layout_swab_lov_user_md(struct lov_user_md *lum, int lum_size)
 	for (i = 0; i < ent_count; i++) {
 		if (comp_v1 != NULL) {
 			ent = &comp_v1->lcm_entries[i];
-			__swab32s(&ent->lcme_id);
-			__swab32s(&ent->lcme_flags);
-			__swab64s(&ent->lcme_timestamp);
-			__swab64s(&ent->lcme_extent.e_start);
-			__swab64s(&ent->lcme_extent.e_end);
-			__swab32s(&ent->lcme_offset);
-			__swab32s(&ent->lcme_size);
+			ent->lcme_id = __swab32(ent->lcme_id);
+			ent->lcme_flags = __swab32(ent->lcme_flags);
+			ent->lcme_timestamp = __swab64(ent->lcme_timestamp);
+			ent->lcme_extent.e_start = __swab64(ent->lcme_extent.e_start);
+			ent->lcme_extent.e_end = __swab64(ent->lcme_extent.e_end);
+			ent->lcme_offset = __swab32(ent->lcme_offset);
+			ent->lcme_size = __swab32(ent->lcme_size);
 
 			lum = (struct lov_user_md *)((char *)comp_v1 +
 					ent->lcme_offset);
@@ -162,11 +162,11 @@ llapi_layout_swab_lov_user_md(struct lov_user_md *lum, int lum_size)
 		}
 		obj_count = llapi_layout_objects_in_lum(lum, lum_size);
 
-		__swab32s(&lum->lmm_magic);
-		__swab32s(&lum->lmm_pattern);
-		__swab32s(&lum->lmm_stripe_size);
-		__swab16s(&lum->lmm_stripe_count);
-		__swab16s(&lum->lmm_stripe_offset);
+		lum->lmm_magic = __swab32(lum->lmm_magic);
+		lum->lmm_pattern = __swab32(lum->lmm_pattern);
+		lum->lmm_stripe_size = __swab32(lum->lmm_stripe_size);
+		lum->lmm_stripe_count = __swab16(lum->lmm_stripe_count);
+		lum->lmm_stripe_offset = __swab16(lum->lmm_stripe_offset);
 
 		if (lum->lmm_magic != LOV_MAGIC_V1) {
 			struct lov_user_md_v3 *v3;
@@ -177,7 +177,7 @@ llapi_layout_swab_lov_user_md(struct lov_user_md *lum, int lum_size)
 		}
 
 		for (j = 0; j < obj_count; j++)
-			__swab32s(&lod[j].l_ost_idx);
+			lod[j].l_ost_idx = __swab32(lod[j].l_ost_idx);
 	}
 }
 
-- 
2.24.0