From 53d860952c8215cf9ae1ea33409c8cb71ad6ad3d Mon Sep 17 00:00:00 2001 From: Jens Thoms Toerring Date: Sun, 31 May 2020 11:53:00 +0200 Subject: [PATCH 1/2] regmap: fix alignment issue The assembly and disassembly of data to be sent to or received from a device invoke functions regmap_format_XX() and regmap_parse_XX() that extract or insert data items from or into a buffer, using assignments. In some cases the functions are called with a buffer pointer with an odd address. On architectures with strict alignment requirements this can result in a kernel crash. The assignments have been replaced by functions that take alignment into account. Signed-off-by: Jens Thoms Toerring Link: https://lore.kernel.org/r/20200531095300.GA27570@toerring.de Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 100 ++++++++++++++++------------------- 1 file changed, 46 insertions(+), 54 deletions(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index c472f624382d..22d125da4a7d 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -17,6 +17,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include "trace.h" @@ -249,22 +250,20 @@ static void regmap_format_8(void *buf, unsigned int val, unsigned int shift) static void regmap_format_16_be(void *buf, unsigned int val, unsigned int shift) { - __be16 *b = buf; - - b[0] = cpu_to_be16(val << shift); + put_unaligned_be16(val << shift, buf); } static void regmap_format_16_le(void *buf, unsigned int val, unsigned int shift) { - __le16 *b = buf; - - b[0] = cpu_to_le16(val << shift); + put_unaligned_le16(val << shift, buf); } static void regmap_format_16_native(void *buf, unsigned int val, unsigned int shift) { - *(u16 *)buf = val << shift; + u16 v = val << shift; + + memcpy(buf, &v, sizeof(v)); } static void regmap_format_24(void *buf, unsigned int val, unsigned int shift) @@ -280,43 +279,39 @@ static void regmap_format_24(void *buf, unsigned int val, unsigned int shift) static void regmap_format_32_be(void *buf, unsigned int val, unsigned int shift) { - __be32 *b = buf; - - b[0] = cpu_to_be32(val << shift); + put_unaligned_be32(val << shift, buf); } static void regmap_format_32_le(void *buf, unsigned int val, unsigned int shift) { - __le32 *b = buf; - - b[0] = cpu_to_le32(val << shift); + put_unaligned_le32(val << shift, buf); } static void regmap_format_32_native(void *buf, unsigned int val, unsigned int shift) { - *(u32 *)buf = val << shift; + u32 v = val << shift; + + memcpy(buf, &v, sizeof(v)); } #ifdef CONFIG_64BIT static void regmap_format_64_be(void *buf, unsigned int val, unsigned int shift) { - __be64 *b = buf; - - b[0] = cpu_to_be64((u64)val << shift); + put_unaligned_be64((u64) val << shift, buf); } static void regmap_format_64_le(void *buf, unsigned int val, unsigned int shift) { - __le64 *b = buf; - - b[0] = cpu_to_le64((u64)val << shift); + put_unaligned_le64((u64) val << shift, buf); } static void regmap_format_64_native(void *buf, unsigned int val, unsigned int shift) { - *(u64 *)buf = (u64)val << shift; + u64 v = (u64) val << shift; + + memcpy(buf, &v, sizeof(v)); } #endif @@ -333,35 +328,34 @@ static unsigned int regmap_parse_8(const void *buf) static unsigned int regmap_parse_16_be(const void *buf) { - const __be16 *b = buf; - - return be16_to_cpu(b[0]); + return get_unaligned_be16(buf); } static unsigned int regmap_parse_16_le(const void *buf) { - const __le16 *b = buf; - - return le16_to_cpu(b[0]); + return get_unaligned_le16(buf); } static void regmap_parse_16_be_inplace(void *buf) { - __be16 *b = buf; + u16 v = get_unaligned_be16(buf); - b[0] = be16_to_cpu(b[0]); + memcpy(buf, &v, sizeof(v)); } static void regmap_parse_16_le_inplace(void *buf) { - __le16 *b = buf; + u16 v = get_unaligned_le16(buf); - b[0] = le16_to_cpu(b[0]); + memcpy(buf, &v, sizeof(v)); } static unsigned int regmap_parse_16_native(const void *buf) { - return *(u16 *)buf; + u16 v; + + memcpy(&v, buf, sizeof(v)); + return v; } static unsigned int regmap_parse_24(const void *buf) @@ -376,69 +370,67 @@ static unsigned int regmap_parse_24(const void *buf) static unsigned int regmap_parse_32_be(const void *buf) { - const __be32 *b = buf; - - return be32_to_cpu(b[0]); + return get_unaligned_be32(buf); } static unsigned int regmap_parse_32_le(const void *buf) { - const __le32 *b = buf; - - return le32_to_cpu(b[0]); + return get_unaligned_le32(buf); } static void regmap_parse_32_be_inplace(void *buf) { - __be32 *b = buf; + u32 v = get_unaligned_be32(buf); - b[0] = be32_to_cpu(b[0]); + memcpy(buf, &v, sizeof(v)); } static void regmap_parse_32_le_inplace(void *buf) { - __le32 *b = buf; + u32 v = get_unaligned_le32(buf); - b[0] = le32_to_cpu(b[0]); + memcpy(buf, &v, sizeof(v)); } static unsigned int regmap_parse_32_native(const void *buf) { - return *(u32 *)buf; + u32 v; + + memcpy(&v, buf, sizeof(v)); + return v; } #ifdef CONFIG_64BIT static unsigned int regmap_parse_64_be(const void *buf) { - const __be64 *b = buf; - - return be64_to_cpu(b[0]); + return get_unaligned_be64(buf); } static unsigned int regmap_parse_64_le(const void *buf) { - const __le64 *b = buf; - - return le64_to_cpu(b[0]); + return get_unaligned_le64(buf); } static void regmap_parse_64_be_inplace(void *buf) { - __be64 *b = buf; + u64 v = get_unaligned_be64(buf); - b[0] = be64_to_cpu(b[0]); + memcpy(buf, &v, sizeof(v)); } static void regmap_parse_64_le_inplace(void *buf) { - __le64 *b = buf; + u64 v = get_unaligned_le64(buf); - b[0] = le64_to_cpu(b[0]); + memcpy(buf, &v, sizeof(v)); } static unsigned int regmap_parse_64_native(const void *buf) { - return *(u64 *)buf; + u64 v; + + memcpy(&v, buf, sizeof(v)); + return v; } #endif From e680a4098f6404191e0e438a9758715b0bff6d7f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Sun, 7 Jun 2020 11:34:21 +0200 Subject: [PATCH 2/2] regmap: fix the kerneldoc for regmap_test_bits() The kerneldoc comment for regmap_test_bits() says that it returns -1 on regmap_read() failure. This is not true - it will propagate the error code returned by regmap_read(). Fix it. Fixes: aa2ff9dbaedd ("regmap: provide helpers for simple bit operations") Signed-off-by: Bartosz Golaszewski Link: https://lore.kernel.org/r/20200607093421.22209-1-brgl@bgdev.pl Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 22d125da4a7d..183ec789c3fd 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -2936,8 +2936,9 @@ EXPORT_SYMBOL_GPL(regmap_update_bits_base); * @reg: Register to read from * @bits: Bits to test * - * Returns -1 if the underlying regmap_read() fails, 0 if at least one of the - * tested bits is not set and 1 if all tested bits are set. + * Returns 0 if at least one of the tested bits is not set, 1 if all tested + * bits are set and a negative error number if the underlying regmap_read() + * fails. */ int regmap_test_bits(struct regmap *map, unsigned int reg, unsigned int bits) {