[PATCH AUTOSEL 5.4 09/19] sparc32: page align size in arch_dma_alloc

[PATCH AUTOSEL 5.4 09/19] sparc32: page align size in arch_dma_alloc

[Sasha Levin]

From: Andreas Larsson <andreas@gaisler.com>

[ Upstream commit 59583f747664046aaae5588d56d5954fab66cce8 ]

Commit 53b7670e5735 ("sparc: factor the dma coherent mapping into
helper") lost the page align for the calls to dma_make_coherent and
srmmu_unmapiorange. The latter cannot handle a non page aligned len
argument.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/sparc/kernel/ioport.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
index f89603855f1e..b87e0002131d 100644
--- a/arch/sparc/kernel/ioport.c
+++ b/arch/sparc/kernel/ioport.c
@@ -356,7 +356,9 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
 		dma_addr_t dma_addr, unsigned long attrs)
 {
-	if (!sparc_dma_free_resource(cpu_addr, PAGE_ALIGN(size)))
+	size = PAGE_ALIGN(size);
+
+	if (!sparc_dma_free_resource(cpu_addr, size))
 		return;
 
 	dma_make_coherent(dma_addr, size);
-- 
2.30.2

[PATCH AUTOSEL 5.4 13/19] sparc: avoid stringop-overread errors

[Sasha Levin]

From: Linus Torvalds <torvalds@linux-foundation.org>

[ Upstream commit fc7c028dcdbfe981bca75d2a7b95f363eb691ef3 ]

The sparc mdesc code does pointer games with 'struct mdesc_hdr', but
didn't describe to the compiler how that header is then followed by the
data that the header describes.

As a result, gcc is now unhappy since it does stricter pointer range
tracking, and doesn't understand about how these things work.  This
results in various errors like:

    arch/sparc/kernel/mdesc.c: In function ‘mdesc_node_by_name’:
    arch/sparc/kernel/mdesc.c:647:22: error: ‘strcmp’ reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread]
      647 |                 if (!strcmp(names + ep[ret].name_offset, name))
          |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

which are easily avoided by just describing 'struct mdesc_hdr' better,
and making the node_block() helper function look into that unsized
data[] that follows the header.

This makes the sparc64 build happy again at least for my cross-compiler
version (gcc version 11.2.1).

Link: https://lore.kernel.org/lkml/CAHk-=wi4NW3NC0xWykkw=6LnjQD6D_rtRtxY9g8gQAJXtQMi8A@mail.gmail.com/
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/sparc/kernel/mdesc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c
index 8e645ddac58e..30f171b7b00c 100644
--- a/arch/sparc/kernel/mdesc.c
+++ b/arch/sparc/kernel/mdesc.c
@@ -39,6 +39,7 @@ struct mdesc_hdr {
 	u32	node_sz; /* node block size */
 	u32	name_sz; /* name block size */
 	u32	data_sz; /* data block size */
+	char	data[];
 } __attribute__((aligned(16)));
 
 struct mdesc_elem {
@@ -612,7 +613,7 @@ EXPORT_SYMBOL(mdesc_get_node_info);
 
 static struct mdesc_elem *node_block(struct mdesc_hdr *mdesc)
 {
-	return (struct mdesc_elem *) (mdesc + 1);
+	return (struct mdesc_elem *) mdesc->data;
 }
 
 static void *name_block(struct mdesc_hdr *mdesc)
-- 
2.30.2