[merged] powerpc-spufs-fix-copy_to_user-while-atomic.patch removed from -mm tree

[merged] powerpc-spufs-fix-copy_to_user-while-atomic.patch removed from -mm tree

[akpm]

The patch titled
     Subject: powerpc/spufs: fix copy_to_user while atomic
has been removed from the -mm tree.  Its filename was
     powerpc-spufs-fix-copy_to_user-while-atomic.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Jeremy Kerr <jk@ozlabs.org>
Subject: powerpc/spufs: fix copy_to_user while atomic

Patch series "remove set_fs calls from the coredump code", v6.

This series gets rid of playing with the address limit in the exec and
coredump code.  Most of this was fairly trivial, the biggest changes are
those to the spufs coredump code.


This patch (of 7):

Currently, we may perform a copy_to_user (through
simple_read_from_buffer()) while holding a context's register_lock, while
accessing the context save area.

This change uses a temporary buffer for the context save area data, which
we then pass to simple_read_from_buffer.

Includes changes from Christoph Hellwig <hch@lst.de>.

[hch: renamed to function to avoid ___-prefixes]
Link: http://lkml.kernel.org/r/20200505101256.3121270-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200505101256.3121270-2-hch@lst.de
Fixes: bf1ab978be23 ("[POWERPC] coredump: Add SPU elf notes to coredump.")
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/powerpc/platforms/cell/spufs/file.c |  113 +++++++++++++--------
 1 file changed, 75 insertions(+), 38 deletions(-)

--- a/arch/powerpc/platforms/cell/spufs/file.c~powerpc-spufs-fix-copy_to_user-while-atomic
+++ a/arch/powerpc/platforms/cell/spufs/file.c
@@ -1978,8 +1978,9 @@ static ssize_t __spufs_mbox_info_read(st
 static ssize_t spufs_mbox_info_read(struct file *file, char __user *buf,
 				   size_t len, loff_t *pos)
 {
-	int ret;
 	struct spu_context *ctx = file->private_data;
+	u32 stat, data;
+	int ret;
 
 	if (!access_ok(buf, len))
 		return -EFAULT;
@@ -1988,11 +1989,16 @@ static ssize_t spufs_mbox_info_read(stru
 	if (ret)
 		return ret;
 	spin_lock(&ctx->csa.register_lock);
-	ret = __spufs_mbox_info_read(ctx, buf, len, pos);
+	stat = ctx->csa.prob.mb_stat_R;
+	data = ctx->csa.prob.pu_mb_R;
 	spin_unlock(&ctx->csa.register_lock);
 	spu_release_saved(ctx);
 
-	return ret;
+	/* EOF if there's no entry in the mbox */
+	if (!(stat & 0x0000ff))
+		return 0;
+
+	return simple_read_from_buffer(buf, len, pos, &data, sizeof(data));
 }
 
 static const struct file_operations spufs_mbox_info_fops = {
@@ -2019,6 +2025,7 @@ static ssize_t spufs_ibox_info_read(stru
 				   size_t len, loff_t *pos)
 {
 	struct spu_context *ctx = file->private_data;
+	u32 stat, data;
 	int ret;
 
 	if (!access_ok(buf, len))
@@ -2028,11 +2035,16 @@ static ssize_t spufs_ibox_info_read(stru
 	if (ret)
 		return ret;
 	spin_lock(&ctx->csa.register_lock);
-	ret = __spufs_ibox_info_read(ctx, buf, len, pos);
+	stat = ctx->csa.prob.mb_stat_R;
+	data = ctx->csa.priv2.puint_mb_R;
 	spin_unlock(&ctx->csa.register_lock);
 	spu_release_saved(ctx);
 
-	return ret;
+	/* EOF if there's no entry in the ibox */
+	if (!(stat & 0xff0000))
+		return 0;
+
+	return simple_read_from_buffer(buf, len, pos, &data, sizeof(data));
 }
 
 static const struct file_operations spufs_ibox_info_fops = {
@@ -2041,6 +2053,11 @@ static const struct file_operations spuf
 	.llseek  = generic_file_llseek,
 };
 
+static size_t spufs_wbox_info_cnt(struct spu_context *ctx)
+{
+	return (4 - ((ctx->csa.prob.mb_stat_R & 0x00ff00) >> 8)) * sizeof(u32);
+}
+
 static ssize_t __spufs_wbox_info_read(struct spu_context *ctx,
 			char __user *buf, size_t len, loff_t *pos)
 {
@@ -2049,7 +2066,7 @@ static ssize_t __spufs_wbox_info_read(st
 	u32 wbox_stat;
 
 	wbox_stat = ctx->csa.prob.mb_stat_R;
-	cnt = 4 - ((wbox_stat & 0x00ff00) >> 8);
+	cnt = spufs_wbox_info_cnt(ctx);
 	for (i = 0; i < cnt; i++) {
 		data[i] = ctx->csa.spu_mailbox_data[i];
 	}
@@ -2062,7 +2079,8 @@ static ssize_t spufs_wbox_info_read(stru
 				   size_t len, loff_t *pos)
 {
 	struct spu_context *ctx = file->private_data;
-	int ret;
+	u32 data[ARRAY_SIZE(ctx->csa.spu_mailbox_data)];
+	int ret, count;
 
 	if (!access_ok(buf, len))
 		return -EFAULT;
@@ -2071,11 +2089,13 @@ static ssize_t spufs_wbox_info_read(stru
 	if (ret)
 		return ret;
 	spin_lock(&ctx->csa.register_lock);
-	ret = __spufs_wbox_info_read(ctx, buf, len, pos);
+	count = spufs_wbox_info_cnt(ctx);
+	memcpy(&data, &ctx->csa.spu_mailbox_data, sizeof(data));
 	spin_unlock(&ctx->csa.register_lock);
 	spu_release_saved(ctx);
 
-	return ret;
+	return simple_read_from_buffer(buf, len, pos, &data,
+				count * sizeof(u32));
 }
 
 static const struct file_operations spufs_wbox_info_fops = {
@@ -2084,27 +2104,33 @@ static const struct file_operations spuf
 	.llseek  = generic_file_llseek,
 };
 
-static ssize_t __spufs_dma_info_read(struct spu_context *ctx,
-			char __user *buf, size_t len, loff_t *pos)
+static void spufs_get_dma_info(struct spu_context *ctx,
+		struct spu_dma_info *info)
 {
-	struct spu_dma_info info;
-	struct mfc_cq_sr *qp, *spuqp;
 	int i;
 
-	info.dma_info_type = ctx->csa.priv2.spu_tag_status_query_RW;
-	info.dma_info_mask = ctx->csa.lscsa->tag_mask.slot[0];
-	info.dma_info_status = ctx->csa.spu_chnldata_RW[24];
-	info.dma_info_stall_and_notify = ctx->csa.spu_chnldata_RW[25];
-	info.dma_info_atomic_command_status = ctx->csa.spu_chnldata_RW[27];
+	info->dma_info_type = ctx->csa.priv2.spu_tag_status_query_RW;
+	info->dma_info_mask = ctx->csa.lscsa->tag_mask.slot[0];
+	info->dma_info_status = ctx->csa.spu_chnldata_RW[24];
+	info->dma_info_stall_and_notify = ctx->csa.spu_chnldata_RW[25];
+	info->dma_info_atomic_command_status = ctx->csa.spu_chnldata_RW[27];
 	for (i = 0; i < 16; i++) {
-		qp = &info.dma_info_command_data[i];
-		spuqp = &ctx->csa.priv2.spuq[i];
+		struct mfc_cq_sr *qp = &info->dma_info_command_data[i];
+		struct mfc_cq_sr *spuqp = &ctx->csa.priv2.spuq[i];
 
 		qp->mfc_cq_data0_RW = spuqp->mfc_cq_data0_RW;
 		qp->mfc_cq_data1_RW = spuqp->mfc_cq_data1_RW;
 		qp->mfc_cq_data2_RW = spuqp->mfc_cq_data2_RW;
 		qp->mfc_cq_data3_RW = spuqp->mfc_cq_data3_RW;
 	}
+}
+
+static ssize_t __spufs_dma_info_read(struct spu_context *ctx,
+			char __user *buf, size_t len, loff_t *pos)
+{
+	struct spu_dma_info info;
+
+	spufs_get_dma_info(ctx, &info);
 
 	return simple_read_from_buffer(buf, len, pos, &info,
 				sizeof info);
@@ -2114,6 +2140,7 @@ static ssize_t spufs_dma_info_read(struc
 			      size_t len, loff_t *pos)
 {
 	struct spu_context *ctx = file->private_data;
+	struct spu_dma_info info;
 	int ret;
 
 	if (!access_ok(buf, len))
@@ -2123,11 +2150,12 @@ static ssize_t spufs_dma_info_read(struc
 	if (ret)
 		return ret;
 	spin_lock(&ctx->csa.register_lock);
-	ret = __spufs_dma_info_read(ctx, buf, len, pos);
+	spufs_get_dma_info(ctx, &info);
 	spin_unlock(&ctx->csa.register_lock);
 	spu_release_saved(ctx);
 
-	return ret;
+	return simple_read_from_buffer(buf, len, pos, &info,
+				sizeof(info));
 }
 
 static const struct file_operations spufs_dma_info_fops = {
@@ -2136,13 +2164,31 @@ static const struct file_operations spuf
 	.llseek = no_llseek,
 };
 
+static void spufs_get_proxydma_info(struct spu_context *ctx,
+		struct spu_proxydma_info *info)
+{
+	int i;
+
+	info->proxydma_info_type = ctx->csa.prob.dma_querytype_RW;
+	info->proxydma_info_mask = ctx->csa.prob.dma_querymask_RW;
+	info->proxydma_info_status = ctx->csa.prob.dma_tagstatus_R;
+
+	for (i = 0; i < 8; i++) {
+		struct mfc_cq_sr *qp = &info->proxydma_info_command_data[i];
+		struct mfc_cq_sr *puqp = &ctx->csa.priv2.puq[i];
+
+		qp->mfc_cq_data0_RW = puqp->mfc_cq_data0_RW;
+		qp->mfc_cq_data1_RW = puqp->mfc_cq_data1_RW;
+		qp->mfc_cq_data2_RW = puqp->mfc_cq_data2_RW;
+		qp->mfc_cq_data3_RW = puqp->mfc_cq_data3_RW;
+	}
+}
+
 static ssize_t __spufs_proxydma_info_read(struct spu_context *ctx,
 			char __user *buf, size_t len, loff_t *pos)
 {
 	struct spu_proxydma_info info;
-	struct mfc_cq_sr *qp, *puqp;
 	int ret = sizeof info;
-	int i;
 
 	if (len < ret)
 		return -EINVAL;
@@ -2150,18 +2196,7 @@ static ssize_t __spufs_proxydma_info_rea
 	if (!access_ok(buf, len))
 		return -EFAULT;
 
-	info.proxydma_info_type = ctx->csa.prob.dma_querytype_RW;
-	info.proxydma_info_mask = ctx->csa.prob.dma_querymask_RW;
-	info.proxydma_info_status = ctx->csa.prob.dma_tagstatus_R;
-	for (i = 0; i < 8; i++) {
-		qp = &info.proxydma_info_command_data[i];
-		puqp = &ctx->csa.priv2.puq[i];
-
-		qp->mfc_cq_data0_RW = puqp->mfc_cq_data0_RW;
-		qp->mfc_cq_data1_RW = puqp->mfc_cq_data1_RW;
-		qp->mfc_cq_data2_RW = puqp->mfc_cq_data2_RW;
-		qp->mfc_cq_data3_RW = puqp->mfc_cq_data3_RW;
-	}
+	spufs_get_proxydma_info(ctx, &info);
 
 	return simple_read_from_buffer(buf, len, pos, &info,
 				sizeof info);
@@ -2171,17 +2206,19 @@ static ssize_t spufs_proxydma_info_read(
 				   size_t len, loff_t *pos)
 {
 	struct spu_context *ctx = file->private_data;
+	struct spu_proxydma_info info;
 	int ret;
 
 	ret = spu_acquire_saved(ctx);
 	if (ret)
 		return ret;
 	spin_lock(&ctx->csa.register_lock);
-	ret = __spufs_proxydma_info_read(ctx, buf, len, pos);
+	spufs_get_proxydma_info(ctx, &info);
 	spin_unlock(&ctx->csa.register_lock);
 	spu_release_saved(ctx);
 
-	return ret;
+	return simple_read_from_buffer(buf, len, pos, &info,
+				sizeof(info));
 }
 
 static const struct file_operations spufs_proxydma_info_fops = {
_

Patches currently in -mm which might be from jk@ozlabs.org are