From: Alastair D'Silva <alastair@xxxxxxxxxxx> The behaviour of hexdump groups is to print the data out as if it was a native-endian number. This patch tweaks the documentation to make this clear, and also adds the HEXDUMP_RETAIN_BYTE_ORDER flag to allow groups of multiple bytes to be printed without affecting the ordering of the printed bytes. Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx> --- include/linux/printk.h | 1 + lib/hexdump.c | 30 ++++++++++++++++---- lib/test_hexdump.c | 62 ++++++++++++++++++++++++++++-------------- 3 files changed, 68 insertions(+), 25 deletions(-) diff --git a/include/linux/printk.h b/include/linux/printk.h index 1d082291facf..ed1a79aa9695 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -491,6 +491,7 @@ enum { #define HEXDUMP_2_GRP_SPACES BIT(5) #define HEXDUMP_4_GRP_SPACES BIT(6) #define HEXDUMP_8_GRP_SPACES BIT(7) +#define HEXDUMP_RETAIN_BYTE_ORDER BIT(8) extern int hex_dump_to_buffer_ext(const void *buf, size_t len, int rowsize, int groupsize, char *linebuf, size_t linebuflen, diff --git a/lib/hexdump.c b/lib/hexdump.c index e09e3cf8e595..29024eccf5da 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -127,7 +127,8 @@ static void separator_parameters(u64 flags, int groupsize, int *sep_chars, * @buf: data blob to dump * @len: number of bytes in the @buf * @rowsize: number of bytes to print per line; must be a multiple of groupsize - * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) + * @groupsize: number of bytes to convert to a native endian number and print: + * 1, 2, 4, 8; default = 1 * @linebuf: where to put the converted data * @linebuflen: total size of @linebuf, including space for terminating NUL * @flags: A bitwise OR of the following flags: @@ -138,6 +139,9 @@ static void separator_parameters(u64 flags, int groupsize, int *sep_chars, * HEXDUMP_2_GRP_SPACES: insert a ' ' after every 2 groups * HEXDUMP_4_GRP_SPACES: insert a ' ' after every 4 groups * HEXDUMP_8_GRP_SPACES: insert a ' ' after every 8 groups + * HEXDUMP_RETAIN_BYTE_ORDER: Retain the byte ordering of groups + * instead of treating each group as a + * native-endian number * * hex_dump_to_buffer() works on one "line" of output at a time, converting * <groupsize> bytes of input to hexadecimal (and optionally printable ASCII) @@ -172,6 +176,7 @@ int hex_dump_to_buffer_ext(const void *buf, size_t len, int rowsize, int ret; int sep_chars = 0; char sep = 0; + bool big_endian = (flags & HEXDUMP_RETAIN_BYTE_ORDER) ? 1 : 0; if (!is_power_of_2(groupsize) || groupsize > 8) groupsize = 1; @@ -203,10 +208,13 @@ int hex_dump_to_buffer_ext(const void *buf, size_t len, int rowsize, const u64 *ptr8 = buf; for (j = 0; j < ngroups; j++) { + u64 val = big_endian ? + be64_to_cpu(get_unaligned(ptr8 + j)) : + get_unaligned(ptr8 + j); ret = snprintf(linebuf + lx, linebuflen - lx, "%s%16.16llx", j ? group_separator(j, flags) : "", - get_unaligned(ptr8 + j)); + val); if (ret >= linebuflen - lx) goto overflow1; lx += ret; @@ -215,10 +223,14 @@ int hex_dump_to_buffer_ext(const void *buf, size_t len, int rowsize, const u32 *ptr4 = buf; for (j = 0; j < ngroups; j++) { + u32 val = big_endian ? + be32_to_cpu(get_unaligned(ptr4 + j)) : + get_unaligned(ptr4 + j); + ret = snprintf(linebuf + lx, linebuflen - lx, "%s%8.8x", j ? group_separator(j, flags) : "", - get_unaligned(ptr4 + j)); + val); if (ret >= linebuflen - lx) goto overflow1; lx += ret; @@ -227,10 +239,14 @@ int hex_dump_to_buffer_ext(const void *buf, size_t len, int rowsize, const u16 *ptr2 = buf; for (j = 0; j < ngroups; j++) { + u16 val = big_endian ? + be16_to_cpu(get_unaligned(ptr2 + j)) : + get_unaligned(ptr2 + j); + ret = snprintf(linebuf + lx, linebuflen - lx, "%s%4.4x", j ? group_separator(j, flags) : "", - get_unaligned(ptr2 + j)); + val); if (ret >= linebuflen - lx) goto overflow1; lx += ret; @@ -332,7 +348,8 @@ static void announce_skipped(const char *level, const char *prefix_str, * @prefix_type: controls whether prefix of an offset, address, or none * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) * @rowsize: number of bytes to print per line; must be a multiple of groupsize - * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) + * @groupsize: number of bytes to convert to a native endian number and print: + * 1, 2, 4, 8; default = 1 * @buf: data blob to dump * @len: number of bytes in the @buf * @ascii: include ASCII after the hex output @@ -343,6 +360,9 @@ static void announce_skipped(const char *level, const char *prefix_str, * HEXDUMP_2_GRP_LINES: insert a '|' after every 2 groups * HEXDUMP_4_GRP_LINES: insert a '|' after every 4 groups * HEXDUMP_8_GRP_LINES: insert a '|' after every 8 groups + * HEXDUMP_RETAIN_BYTE_ORDER: Retain the byte ordering of groups + * instead of treating each group as a + * native-endian number * * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump * to the kernel log at the specified kernel log level, with an optional diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c index ad43218437f1..d2cfcb3e2d2b 100644 --- a/lib/test_hexdump.c +++ b/lib/test_hexdump.c @@ -98,14 +98,15 @@ static unsigned failed_tests __initdata; static void __init test_hexdump_prepare_test(size_t len, int rowsize, int groupsize, char *test, - size_t testlen, bool ascii) + size_t testlen, u64 flags) { char *p; const char * const *result; size_t l = len; int gs = groupsize, rs = rowsize; unsigned int i; - const bool is_be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN); + const bool is_be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) || + (flags & HEXDUMP_RETAIN_BYTE_ORDER); if (l > rs) l = rs; @@ -142,7 +143,7 @@ static void __init test_hexdump_prepare_test(size_t len, int rowsize, p--; /* ASCII part */ - if (ascii) { + if (flags & HEXDUMP_ASCII) { do { *p++ = ' '; } while (p < test + rs * 2 + rs / gs + 1); @@ -157,7 +158,7 @@ static void __init test_hexdump_prepare_test(size_t len, int rowsize, #define TEST_HEXDUMP_BUF_SIZE (64 * 3 + 2 + 64 + 1) static void __init test_hexdump(size_t len, int rowsize, int groupsize, - bool ascii) + u64 flags) { char test[TEST_HEXDUMP_BUF_SIZE]; char real[TEST_HEXDUMP_BUF_SIZE]; @@ -166,12 +167,11 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize, memset(real, FILL_CHAR, sizeof(real)); hex_dump_to_buffer_ext(data_b, len, rowsize, groupsize, - real, sizeof(real), - ascii ? HEXDUMP_ASCII : 0); + real, sizeof(real), flags); memset(test, FILL_CHAR, sizeof(test)); test_hexdump_prepare_test(len, rowsize, groupsize, test, sizeof(test), - ascii); + flags); if (memcmp(test, real, TEST_HEXDUMP_BUF_SIZE)) { pr_err("Len: %zu row: %d group: %d\n", len, rowsize, groupsize); @@ -194,7 +194,7 @@ static void __init test_hexdump_set(int rowsize, bool ascii) static void __init test_hexdump_overflow(size_t buflen, size_t len, int rowsize, int groupsize, - bool ascii) + u64 flags) { char test[TEST_HEXDUMP_BUF_SIZE]; char buf[TEST_HEXDUMP_BUF_SIZE]; @@ -206,8 +206,7 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len, memset(buf, FILL_CHAR, sizeof(buf)); rc = hex_dump_to_buffer_ext(data_b, len, rowsize, groupsize, - buf, buflen, - ascii ? HEXDUMP_ASCII : 0); + buf, buflen, flags); /* * Caller must provide the data length multiple of groupsize. The @@ -224,12 +223,12 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len, - 1 /* no trailing space */; } - expected_len = (ascii) ? ascii_len : hex_len; + expected_len = (flags & HEXDUMP_ASCII) ? ascii_len : hex_len; fill_point = min_t(int, expected_len + 1, buflen); if (buflen) { test_hexdump_prepare_test(len, rowsize, groupsize, test, - sizeof(test), ascii); + sizeof(test), flags); test[fill_point - 1] = '\0'; } memset(test + fill_point, FILL_CHAR, sizeof(test) - fill_point); @@ -239,8 +238,8 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len, buf[sizeof(buf) - 1] = '\0'; if (!match) { - pr_err("rowsize: %u groupsize: %u ascii: %d Len: %zu buflen: %zu strlen: %zu\n", - rowsize, groupsize, ascii, len, buflen, + pr_err("rowsize: %u groupsize: %u flags: %llx Len: %zu buflen: %zu strlen: %zu\n", + rowsize, groupsize, flags, len, buflen, strnlen(buf, sizeof(buf))); pr_err("Result: %d '%-.*s'\n", rc, (int)buflen, buf); pr_err("Expect: %d '%-.*s'\n", expected_len, (int)buflen, test); @@ -249,7 +248,7 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len, } } -static void __init test_hexdump_overflow_set(size_t buflen, bool ascii) +static void __init test_hexdump_overflow_set(size_t buflen, u64 flags) { unsigned int i = 0; int rs = (get_random_int() % 4 + 1) * 16; @@ -258,7 +257,7 @@ static void __init test_hexdump_overflow_set(size_t buflen, bool ascii) int gs = 1 << i; size_t len = get_random_int() % rs + gs; - test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii); + test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, flags); } while (i++ < 3); } @@ -266,20 +265,43 @@ static int __init test_hexdump_init(void) { unsigned int i; int rowsize; + u64 flags; + flags = 0; rowsize = (get_random_int() % 4 + 1) * 16; for (i = 0; i < 16; i++) - test_hexdump_set(rowsize, false); + test_hexdump_set(rowsize, flags); + flags = HEXDUMP_ASCII; rowsize = (get_random_int() % 4 + 1) * 16; for (i = 0; i < 16; i++) - test_hexdump_set(rowsize, true); + test_hexdump_set(rowsize, flags); + flags = HEXDUMP_RETAIN_BYTE_ORDER; + rowsize = (get_random_int() % 2 + 1) * 16; + for (i = 0; i < 16; i++) + test_hexdump_set(rowsize, flags); + + flags = HEXDUMP_ASCII | HEXDUMP_RETAIN_BYTE_ORDER; + rowsize = (get_random_int() % 2 + 1) * 16; + for (i = 0; i < 16; i++) + test_hexdump_set(rowsize, flags); + + flags = 0; + for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++) + test_hexdump_overflow_set(i, flags); + + flags = HEXDUMP_ASCII; + for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++) + test_hexdump_overflow_set(i, flags); + + flags = HEXDUMP_RETAIN_BYTE_ORDER; for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++) - test_hexdump_overflow_set(i, false); + test_hexdump_overflow_set(i, flags); + flags = HEXDUMP_ASCII | HEXDUMP_RETAIN_BYTE_ORDER; for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++) - test_hexdump_overflow_set(i, true); + test_hexdump_overflow_set(i, flags); if (failed_tests == 0) pr_info("all %u tests passed\n", total_tests); -- 2.21.0 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel