| Message ID | 20240412073346.458116-4-richard.henderson@linaro.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | misc: Replace sprintf | expand |
On 12/4/24 09:33, Richard Henderson wrote: > Allocate a new, or append to an existing GString instead of > using a fixed sized buffer. Require the caller to determine > the length of the line -- do not bound len here. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > include/qemu/cutils.h | 15 ++++++++++----- > hw/virtio/vhost-vdpa.c | 14 ++++++++------ > util/hexdump.c | 29 +++++++++++++++++------------ > 3 files changed, 35 insertions(+), 23 deletions(-) > > diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h > index d0c5386e6c..7311fb36ca 100644 > --- a/include/qemu/cutils.h > +++ b/include/qemu/cutils.h > @@ -252,12 +252,17 @@ static inline const char *yes_no(bool b) > */ > int parse_debug_env(const char *name, int max, int initial); > > -/* > - * Hexdump a line of a byte buffer into a hexadecimal/ASCII buffer > +/** > + * qemu_hexdump_line: > + * @str: GString into which to append > + * @buf: buffer to dump > + * @len: number of bytes to dump > + * > + * Append @len bytes of @buf as hexadecimal into @str. > + * If @str is NULL, allocate a new string and return it; > + * otherwise return @str. > */ > -#define QEMU_HEXDUMP_LINE_BYTES 16 /* Number of bytes to dump */ > -#define QEMU_HEXDUMP_LINE_LEN 75 /* Number of characters in line */ > -void qemu_hexdump_line(char *line, const void *bufptr, size_t len); > +GString *qemu_hexdump_line(GString *str, const void *buf, size_t len); > diff --git a/util/hexdump.c b/util/hexdump.c > index dbc536fe84..521e346bc6 100644 > --- a/util/hexdump.c > +++ b/util/hexdump.c > @@ -16,22 +16,25 @@ > #include "qemu/osdep.h" > #include "qemu/cutils.h" > > -void qemu_hexdump_line(char *line, const void *bufptr, size_t len) > +GString *qemu_hexdump_line(GString *str, const void *vbuf, size_t len) > { > - const char *buf = bufptr; > - int i, c; > + const uint8_t *buf = vbuf; > + size_t i; > > - if (len > QEMU_HEXDUMP_LINE_BYTES) { > - len = QEMU_HEXDUMP_LINE_BYTES; > + if (str == NULL) { > + /* Estimate the length of the output to avoid reallocs. */ > + i = len * 3 + len / 4; > + str = g_string_sized_new(i + 1); > } [*] else { g_string_truncate(str, 0); } > > for (i = 0; i < len; i++) { > if (i != 0 && (i % 4) == 0) { > - *line++ = ' '; > + g_string_append_c(str, ' '); > } > - line += sprintf(line, " %02x", (unsigned char)buf[i]); > + g_string_append_printf(str, " %02x", buf[i]); > } > - *line = '\0'; > + > + return str; > } > > static void asciidump_line(char *line, const void *bufptr, size_t len) > @@ -49,24 +52,26 @@ static void asciidump_line(char *line, const void *bufptr, size_t len) > *line = '\0'; > } > > +#define QEMU_HEXDUMP_LINE_BYTES 16 > #define QEMU_HEXDUMP_LINE_WIDTH \ > (QEMU_HEXDUMP_LINE_BYTES * 2 + QEMU_HEXDUMP_LINE_BYTES / 4) > > void qemu_hexdump(FILE *fp, const char *prefix, > const void *bufptr, size_t size) > { > - char line[QEMU_HEXDUMP_LINE_LEN]; > + g_autoptr(GString) str = g_string_sized_new(QEMU_HEXDUMP_LINE_WIDTH + 1); > char ascii[QEMU_HEXDUMP_LINE_BYTES + 1]; > size_t b, len; > > for (b = 0; b < size; b += len) { > len = MIN(size - b, QEMU_HEXDUMP_LINE_BYTES); > > - qemu_hexdump_line(line, bufptr + b, len); > + g_string_truncate(str, 0); Shouldn't we truncate in [*] ? > + qemu_hexdump_line(str, bufptr + b, len); > asciidump_line(ascii, bufptr + b, len); > > - fprintf(fp, "%s: %04x: %-*s %s\n", > - prefix, b, QEMU_HEXDUMP_LINE_WIDTH, line, ascii); > + fprintf(fp, "%s: %04zx: %-*s %s\n", > + prefix, b, QEMU_HEXDUMP_LINE_WIDTH, str->str, ascii); > } > > }
On 4/12/24 10:41, Philippe Mathieu-Daudé wrote: >> -void qemu_hexdump_line(char *line, const void *bufptr, size_t len) >> +GString *qemu_hexdump_line(GString *str, const void *vbuf, size_t len) >> { >> - const char *buf = bufptr; >> - int i, c; >> + const uint8_t *buf = vbuf; >> + size_t i; >> - if (len > QEMU_HEXDUMP_LINE_BYTES) { >> - len = QEMU_HEXDUMP_LINE_BYTES; >> + if (str == NULL) { >> + /* Estimate the length of the output to avoid reallocs. */ >> + i = len * 3 + len / 4; >> + str = g_string_sized_new(i + 1); >> } > > [*] > else { > g_string_truncate(str, 0); > } > ... >> @@ -49,24 +52,26 @@ static void asciidump_line(char *line, const void *bufptr, size_t len) >> *line = '\0'; >> } >> +#define QEMU_HEXDUMP_LINE_BYTES 16 >> #define QEMU_HEXDUMP_LINE_WIDTH \ >> (QEMU_HEXDUMP_LINE_BYTES * 2 + QEMU_HEXDUMP_LINE_BYTES / 4) >> void qemu_hexdump(FILE *fp, const char *prefix, >> const void *bufptr, size_t size) >> { >> - char line[QEMU_HEXDUMP_LINE_LEN]; >> + g_autoptr(GString) str = g_string_sized_new(QEMU_HEXDUMP_LINE_WIDTH + 1); >> char ascii[QEMU_HEXDUMP_LINE_BYTES + 1]; >> size_t b, len; >> for (b = 0; b < size; b += len) { >> len = MIN(size - b, QEMU_HEXDUMP_LINE_BYTES); >> - qemu_hexdump_line(line, bufptr + b, len); >> + g_string_truncate(str, 0); > > Shouldn't we truncate in [*] ? The usage in tpm puts several lines together in one string, adding \n in between, for output in one go. r~
On 12/4/24 20:59, Richard Henderson wrote: > On 4/12/24 10:41, Philippe Mathieu-Daudé wrote: >>> -void qemu_hexdump_line(char *line, const void *bufptr, size_t len) >>> +GString *qemu_hexdump_line(GString *str, const void *vbuf, size_t len) >>> { >>> - const char *buf = bufptr; >>> - int i, c; >>> + const uint8_t *buf = vbuf; >>> + size_t i; >>> - if (len > QEMU_HEXDUMP_LINE_BYTES) { >>> - len = QEMU_HEXDUMP_LINE_BYTES; >>> + if (str == NULL) { >>> + /* Estimate the length of the output to avoid reallocs. */ >>> + i = len * 3 + len / 4; >>> + str = g_string_sized_new(i + 1); >>> } >> >> [*] >> else { >> g_string_truncate(str, 0); >> } >> > ... >>> @@ -49,24 +52,26 @@ static void asciidump_line(char *line, const void >>> *bufptr, size_t len) >>> *line = '\0'; >>> } >>> +#define QEMU_HEXDUMP_LINE_BYTES 16 >>> #define QEMU_HEXDUMP_LINE_WIDTH \ >>> (QEMU_HEXDUMP_LINE_BYTES * 2 + QEMU_HEXDUMP_LINE_BYTES / 4) >>> void qemu_hexdump(FILE *fp, const char *prefix, >>> const void *bufptr, size_t size) >>> { >>> - char line[QEMU_HEXDUMP_LINE_LEN]; >>> + g_autoptr(GString) str = >>> g_string_sized_new(QEMU_HEXDUMP_LINE_WIDTH + 1); >>> char ascii[QEMU_HEXDUMP_LINE_BYTES + 1]; >>> size_t b, len; >>> for (b = 0; b < size; b += len) { >>> len = MIN(size - b, QEMU_HEXDUMP_LINE_BYTES); >>> - qemu_hexdump_line(line, bufptr + b, len); >>> + g_string_truncate(str, 0); >> >> Shouldn't we truncate in [*] ? > > The usage in tpm puts several lines together in one string, > adding \n in between, for output in one go. I see the trace_tpm_util_show_buffer() call. However this isn't a recommended use of the tracing API (Cc'ing Stefan). It breaks the "log" backend output, and is sub-optimal for all other backends. IMHO the TPM buffer should be traced by multiple calls of (offset, hexbuf) instead. Regards, Phil.
On Sat, 13 Apr 2024 at 05:46, Philippe Mathieu-Daudé <philmd@linaro.org> wrote: > > On 12/4/24 20:59, Richard Henderson wrote: > > On 4/12/24 10:41, Philippe Mathieu-Daudé wrote: > >>> -void qemu_hexdump_line(char *line, const void *bufptr, size_t len) > >>> +GString *qemu_hexdump_line(GString *str, const void *vbuf, size_t len) > >>> { > >>> - const char *buf = bufptr; > >>> - int i, c; > >>> + const uint8_t *buf = vbuf; > >>> + size_t i; > >>> - if (len > QEMU_HEXDUMP_LINE_BYTES) { > >>> - len = QEMU_HEXDUMP_LINE_BYTES; > >>> + if (str == NULL) { > >>> + /* Estimate the length of the output to avoid reallocs. */ > >>> + i = len * 3 + len / 4; > >>> + str = g_string_sized_new(i + 1); > >>> } > >> > >> [*] > >> else { > >> g_string_truncate(str, 0); > >> } > >> > > ... > >>> @@ -49,24 +52,26 @@ static void asciidump_line(char *line, const void > >>> *bufptr, size_t len) > >>> *line = '\0'; > >>> } > >>> +#define QEMU_HEXDUMP_LINE_BYTES 16 > >>> #define QEMU_HEXDUMP_LINE_WIDTH \ > >>> (QEMU_HEXDUMP_LINE_BYTES * 2 + QEMU_HEXDUMP_LINE_BYTES / 4) > >>> void qemu_hexdump(FILE *fp, const char *prefix, > >>> const void *bufptr, size_t size) > >>> { > >>> - char line[QEMU_HEXDUMP_LINE_LEN]; > >>> + g_autoptr(GString) str = > >>> g_string_sized_new(QEMU_HEXDUMP_LINE_WIDTH + 1); > >>> char ascii[QEMU_HEXDUMP_LINE_BYTES + 1]; > >>> size_t b, len; > >>> for (b = 0; b < size; b += len) { > >>> len = MIN(size - b, QEMU_HEXDUMP_LINE_BYTES); > >>> - qemu_hexdump_line(line, bufptr + b, len); > >>> + g_string_truncate(str, 0); > >> > >> Shouldn't we truncate in [*] ? > > > > The usage in tpm puts several lines together in one string, > > adding \n in between, for output in one go. > > I see the trace_tpm_util_show_buffer() call. However this > isn't a recommended use of the tracing API (Cc'ing Stefan). > It breaks the "log" backend output, and is sub-optimal for > all other backends. > > IMHO the TPM buffer should be traced by multiple calls of > (offset, hexbuf) instead. I think so too. Stefan
diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h index d0c5386e6c..7311fb36ca 100644 --- a/include/qemu/cutils.h +++ b/include/qemu/cutils.h @@ -252,12 +252,17 @@ static inline const char *yes_no(bool b) */ int parse_debug_env(const char *name, int max, int initial); -/* - * Hexdump a line of a byte buffer into a hexadecimal/ASCII buffer +/** + * qemu_hexdump_line: + * @str: GString into which to append + * @buf: buffer to dump + * @len: number of bytes to dump + * + * Append @len bytes of @buf as hexadecimal into @str. + * If @str is NULL, allocate a new string and return it; + * otherwise return @str. */ -#define QEMU_HEXDUMP_LINE_BYTES 16 /* Number of bytes to dump */ -#define QEMU_HEXDUMP_LINE_LEN 75 /* Number of characters in line */ -void qemu_hexdump_line(char *line, const void *bufptr, size_t len); +GString *qemu_hexdump_line(GString *str, const void *buf, size_t len); /* * Hexdump a buffer to a file. An optional string prefix is added to every line diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index 32bad5ce68..ab047d8ee0 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -941,13 +941,15 @@ static int vhost_vdpa_set_config_call(struct vhost_dev *dev, static void vhost_vdpa_dump_config(struct vhost_dev *dev, const uint8_t *config, uint32_t config_len) { - int b, len; - char line[QEMU_HEXDUMP_LINE_LEN]; + g_autoptr(GString) str = g_string_sized_new(4 * 16); + size_t b, len; - for (b = 0; b < config_len; b += 16) { - len = config_len - b; - qemu_hexdump_line(line, config + b, len); - trace_vhost_vdpa_dump_config(dev, b, line); + for (b = 0; b < config_len; b += len) { + len = MIN(config_len - b, 16); + + g_string_truncate(str, 0); + qemu_hexdump_line(str, config + b, len); + trace_vhost_vdpa_dump_config(dev, b, str->str); } } diff --git a/util/hexdump.c b/util/hexdump.c index dbc536fe84..521e346bc6 100644 --- a/util/hexdump.c +++ b/util/hexdump.c @@ -16,22 +16,25 @@ #include "qemu/osdep.h" #include "qemu/cutils.h" -void qemu_hexdump_line(char *line, const void *bufptr, size_t len) +GString *qemu_hexdump_line(GString *str, const void *vbuf, size_t len) { - const char *buf = bufptr; - int i, c; + const uint8_t *buf = vbuf; + size_t i; - if (len > QEMU_HEXDUMP_LINE_BYTES) { - len = QEMU_HEXDUMP_LINE_BYTES; + if (str == NULL) { + /* Estimate the length of the output to avoid reallocs. */ + i = len * 3 + len / 4; + str = g_string_sized_new(i + 1); } for (i = 0; i < len; i++) { if (i != 0 && (i % 4) == 0) { - *line++ = ' '; + g_string_append_c(str, ' '); } - line += sprintf(line, " %02x", (unsigned char)buf[i]); + g_string_append_printf(str, " %02x", buf[i]); } - *line = '\0'; + + return str; } static void asciidump_line(char *line, const void *bufptr, size_t len) @@ -49,24 +52,26 @@ static void asciidump_line(char *line, const void *bufptr, size_t len) *line = '\0'; } +#define QEMU_HEXDUMP_LINE_BYTES 16 #define QEMU_HEXDUMP_LINE_WIDTH \ (QEMU_HEXDUMP_LINE_BYTES * 2 + QEMU_HEXDUMP_LINE_BYTES / 4) void qemu_hexdump(FILE *fp, const char *prefix, const void *bufptr, size_t size) { - char line[QEMU_HEXDUMP_LINE_LEN]; + g_autoptr(GString) str = g_string_sized_new(QEMU_HEXDUMP_LINE_WIDTH + 1); char ascii[QEMU_HEXDUMP_LINE_BYTES + 1]; size_t b, len; for (b = 0; b < size; b += len) { len = MIN(size - b, QEMU_HEXDUMP_LINE_BYTES); - qemu_hexdump_line(line, bufptr + b, len); + g_string_truncate(str, 0); + qemu_hexdump_line(str, bufptr + b, len); asciidump_line(ascii, bufptr + b, len); - fprintf(fp, "%s: %04x: %-*s %s\n", - prefix, b, QEMU_HEXDUMP_LINE_WIDTH, line, ascii); + fprintf(fp, "%s: %04zx: %-*s %s\n", + prefix, b, QEMU_HEXDUMP_LINE_WIDTH, str->str, ascii); } }
Allocate a new, or append to an existing GString instead of using a fixed sized buffer. Require the caller to determine the length of the line -- do not bound len here. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- include/qemu/cutils.h | 15 ++++++++++----- hw/virtio/vhost-vdpa.c | 14 ++++++++------ util/hexdump.c | 29 +++++++++++++++++------------ 3 files changed, 35 insertions(+), 23 deletions(-)