| Message ID | 20240411101550.99392-5-philmd@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | misc: Remove sprintf() due to macOS deprecation | expand |
On 4/11/24 03:15, Philippe Mathieu-Daudé wrote: > Extract common code from reinitialize_rng_seed() and > load_kernel() to rng_seed_hex_new(). > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> > --- > hw/mips/malta.c | 20 ++++++++++++-------- > 1 file changed, 12 insertions(+), 8 deletions(-) > > diff --git a/hw/mips/malta.c b/hw/mips/malta.c > index af74008c82..9fc6a7d313 100644 > --- a/hw/mips/malta.c > +++ b/hw/mips/malta.c > @@ -850,15 +850,24 @@ static void G_GNUC_PRINTF(3, 4) prom_set(uint32_t *prom_buf, int index, > va_end(ap); > } > > -static void reinitialize_rng_seed(void *opaque) > +static char *rng_seed_hex_new(void) > { > - char *rng_seed_hex = opaque; > uint8_t rng_seed[32]; > + char rng_seed_hex[sizeof(rng_seed) * 2 + 1]; > > qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed)); > for (size_t i = 0; i < sizeof(rng_seed); ++i) { > sprintf(rng_seed_hex + i * 2, "%02x", rng_seed[i]); > } > + > + return g_strdup(rng_seed_hex); > +} > + > +static void reinitialize_rng_seed(void *opaque) > +{ > + g_autofree char *rng_seed_hex = rng_seed_hex_new(); > + > + strcpy(opaque, rng_seed_hex); > } Though it isn't deprecated, strcpy isn't really any safer than sprintf. We don't need to be copying text around quite as much as this. How about: #define RNG_SEED_SIZE 32 static void rng_seed_hex_new(char buf[2 * RNG_SEED_SIZE + 1]) { static const char hex = "0123456789abcdef"; uint8_t rng_seed[RNG_SEED_SIZE]; qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed)); for (int i = 0; i < RNG_SEED_SIZE; ++i) { buf[i * 2 + 0] = hex[rng_seed[i] / 16]; buf[i * 2 + 1] = hex[rng_seed[i] % 16]; } buf[RNG_SEED_SIZE * 2] = '\0'; } static void reinitialize_rng_seed(void *opaque) { rng_seed_hex_new(opaque); } with little change in load_kernel. r~
On 4/11/24 13:07, Richard Henderson wrote: > On 4/11/24 03:15, Philippe Mathieu-Daudé wrote: >> Extract common code from reinitialize_rng_seed() and >> load_kernel() to rng_seed_hex_new(). >> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> >> --- >> hw/mips/malta.c | 20 ++++++++++++-------- >> 1 file changed, 12 insertions(+), 8 deletions(-) >> >> diff --git a/hw/mips/malta.c b/hw/mips/malta.c >> index af74008c82..9fc6a7d313 100644 >> --- a/hw/mips/malta.c >> +++ b/hw/mips/malta.c >> @@ -850,15 +850,24 @@ static void G_GNUC_PRINTF(3, 4) prom_set(uint32_t *prom_buf, int >> index, >> va_end(ap); >> } >> -static void reinitialize_rng_seed(void *opaque) >> +static char *rng_seed_hex_new(void) >> { >> - char *rng_seed_hex = opaque; >> uint8_t rng_seed[32]; >> + char rng_seed_hex[sizeof(rng_seed) * 2 + 1]; >> qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed)); >> for (size_t i = 0; i < sizeof(rng_seed); ++i) { >> sprintf(rng_seed_hex + i * 2, "%02x", rng_seed[i]); >> } >> + >> + return g_strdup(rng_seed_hex); >> +} >> + >> +static void reinitialize_rng_seed(void *opaque) >> +{ >> + g_autofree char *rng_seed_hex = rng_seed_hex_new(); >> + >> + strcpy(opaque, rng_seed_hex); >> } > > Though it isn't deprecated, strcpy isn't really any safer than sprintf. > We don't need to be copying text around quite as much as this. > > How about: > > #define RNG_SEED_SIZE 32 > > static void rng_seed_hex_new(char buf[2 * RNG_SEED_SIZE + 1]) > { > static const char hex = "0123456789abcdef"; > uint8_t rng_seed[RNG_SEED_SIZE]; > > qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed)); > for (int i = 0; i < RNG_SEED_SIZE; ++i) { > buf[i * 2 + 0] = hex[rng_seed[i] / 16]; > buf[i * 2 + 1] = hex[rng_seed[i] % 16]; Hmm. Maybe a static inline char hexdump_nibble(unsigned val) { return (val < 10 ? '0' : 'a') + val; } static inline void hexdump_byte(char *out, uint8_t byte) { out[0] = hexdump_nibble(byte >> 4); out[1] = hexdump_nibble(byte & 15); } in "qemu/cutils.h", for use elsewhere including util/hexdump.c. r~
diff --git a/hw/mips/malta.c b/hw/mips/malta.c index af74008c82..9fc6a7d313 100644 --- a/hw/mips/malta.c +++ b/hw/mips/malta.c @@ -850,15 +850,24 @@ static void G_GNUC_PRINTF(3, 4) prom_set(uint32_t *prom_buf, int index, va_end(ap); } -static void reinitialize_rng_seed(void *opaque) +static char *rng_seed_hex_new(void) { - char *rng_seed_hex = opaque; uint8_t rng_seed[32]; + char rng_seed_hex[sizeof(rng_seed) * 2 + 1]; qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed)); for (size_t i = 0; i < sizeof(rng_seed); ++i) { sprintf(rng_seed_hex + i * 2, "%02x", rng_seed[i]); } + + return g_strdup(rng_seed_hex); +} + +static void reinitialize_rng_seed(void *opaque) +{ + g_autofree char *rng_seed_hex = rng_seed_hex_new(); + + strcpy(opaque, rng_seed_hex); } /* Kernel */ @@ -870,8 +879,7 @@ static uint64_t load_kernel(void) uint32_t *prom_buf; long prom_size; int prom_index = 0; - uint8_t rng_seed[32]; - char rng_seed_hex[sizeof(rng_seed) * 2 + 1]; + g_autofree char *rng_seed_hex = rng_seed_hex_new(); size_t rng_seed_prom_offset; kernel_size = load_elf(loaderparams.kernel_filename, NULL, @@ -946,10 +954,6 @@ static uint64_t load_kernel(void) prom_set(prom_buf, prom_index++, "modetty0"); prom_set(prom_buf, prom_index++, "38400n8r"); - qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed)); - for (size_t i = 0; i < sizeof(rng_seed); ++i) { - sprintf(rng_seed_hex + i * 2, "%02x", rng_seed[i]); - } prom_set(prom_buf, prom_index++, "rngseed"); rng_seed_prom_offset = prom_index * ENVP_ENTRY_SIZE + sizeof(uint32_t) * ENVP_NB_ENTRIES;
Extract common code from reinitialize_rng_seed() and load_kernel() to rng_seed_hex_new(). Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> --- hw/mips/malta.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)