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authorArnd Bergmann <arnd@arndb.de>2017-11-30 06:08:05 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-22 15:45:02 +0100
commitc4fd9c8d38575cfcd90dce8162d52ac74158cefc (patch)
treee29c0d4090eab5192e3c9aa40a0532a9568f3af1
parent193cfa7632a490a86faa3af1969d63c63873d8be (diff)
media: r820t: fix r820t_write_reg for KASAN
commit 16c3ada89cff9a8c2a0eea34ffa1aa20af3f6008 upstream. With CONFIG_KASAN, we get an overly long stack frame due to inlining the register access functions: drivers/media/tuners/r820t.c: In function 'generic_set_freq.isra.7': drivers/media/tuners/r820t.c:1334:1: error: the frame size of 2880 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] This is caused by a gcc bug that has now been fixed in gcc-8. To work around the problem, we can pass the register data through a local variable that older gcc versions can optimize out as well. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/media/tuners/r820t.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/media/tuners/r820t.c b/drivers/media/tuners/r820t.c
index a7a8452e99d2..c1ce8d3ce877 100644
--- a/drivers/media/tuners/r820t.c
+++ b/drivers/media/tuners/r820t.c
@@ -410,9 +410,11 @@ static int r820t_write(struct r820t_priv *priv, u8 reg, const u8 *val,
return 0;
}
-static int r820t_write_reg(struct r820t_priv *priv, u8 reg, u8 val)
+static inline int r820t_write_reg(struct r820t_priv *priv, u8 reg, u8 val)
{
- return r820t_write(priv, reg, &val, 1);
+ u8 tmp = val; /* work around GCC PR81715 with asan-stack=1 */
+
+ return r820t_write(priv, reg, &tmp, 1);
}
static int r820t_read_cache_reg(struct r820t_priv *priv, int reg)
@@ -425,17 +427,18 @@ static int r820t_read_cache_reg(struct r820t_priv *priv, int reg)
return -EINVAL;
}
-static int r820t_write_reg_mask(struct r820t_priv *priv, u8 reg, u8 val,
+static inline int r820t_write_reg_mask(struct r820t_priv *priv, u8 reg, u8 val,
u8 bit_mask)
{
+ u8 tmp = val;
int rc = r820t_read_cache_reg(priv, reg);
if (rc < 0)
return rc;
- val = (rc & ~bit_mask) | (val & bit_mask);
+ tmp = (rc & ~bit_mask) | (tmp & bit_mask);
- return r820t_write(priv, reg, &val, 1);
+ return r820t_write(priv, reg, &tmp, 1);
}
static int r820t_read(struct r820t_priv *priv, u8 reg, u8 *val, int len)