Since commit 55d9950aaa8e ("nvram: Introduce helper functions for CHRP "system" and "free space" partitions") it is possible to pre-initialize a "system" partition in the NVRAM with the data passed to all -prom-env parameters on the QEMU command line.
Unfortunately, this doesn't take the total size of the data into account and chrp_nvram_create_system_partition() may crash at some point if the caller hasn't allocated enough space. Add a dry_run argument that causes chrp_nvram_create_system_partition() to only return the size of the partition without actually copying data into it. This can be used by callers to allocate enough memory. Signed-off-by: Greg Kurz <gr...@kaod.org> --- hw/nvram/chrp_nvram.c | 34 +++++++++++++++++++++++----------- hw/nvram/mac_nvram.c | 2 +- hw/nvram/spapr_nvram.c | 3 ++- hw/sparc/sun4m.c | 2 +- hw/sparc64/sun4u.c | 2 +- include/hw/nvram/chrp_nvram.h | 3 ++- 6 files changed, 30 insertions(+), 16 deletions(-) diff --git a/hw/nvram/chrp_nvram.c b/hw/nvram/chrp_nvram.c index d969f267048e..f5f7b2a97c18 100644 --- a/hw/nvram/chrp_nvram.c +++ b/hw/nvram/chrp_nvram.c @@ -24,37 +24,48 @@ #include "hw/nvram/chrp_nvram.h" #include "sysemu/sysemu.h" -static int chrp_nvram_set_var(uint8_t *nvram, int addr, const char *str) +static int chrp_nvram_set_var(uint8_t *nvram, int addr, const char *str, + bool dry_run) { int len; len = strlen(str) + 1; - memcpy(&nvram[addr], str, len); - + if (!dry_run) { + memcpy(&nvram[addr], str, len); + } return addr + len; } /** * Create a "system partition", used for the Open Firmware - * environment variables. + * environment variables. If @dry_run is false, only returns + * the size of the partition but don't write the data. */ -int chrp_nvram_create_system_partition(uint8_t *data, int min_len) +int chrp_nvram_create_system_partition(uint8_t *data, int min_len, bool dry_run) { ChrpNvramPartHdr *part_header; unsigned int i; int end; + assert(data || dry_run); + part_header = (ChrpNvramPartHdr *)data; - part_header->signature = CHRP_NVPART_SYSTEM; - pstrcpy(part_header->name, sizeof(part_header->name), "system"); + + if (!dry_run) { + part_header->signature = CHRP_NVPART_SYSTEM; + pstrcpy(part_header->name, sizeof(part_header->name), "system"); + } end = sizeof(ChrpNvramPartHdr); for (i = 0; i < nb_prom_envs; i++) { - end = chrp_nvram_set_var(data, end, prom_envs[i]); + end = chrp_nvram_set_var(data, end, prom_envs[i], dry_run); } /* End marker */ - data[end++] = '\0'; + if (!dry_run) { + data[end] = '\0'; + } + end++; end = (end + 15) & ~15; /* XXX: OpenBIOS is not able to grow up a partition. Leave some space for @@ -62,8 +73,9 @@ int chrp_nvram_create_system_partition(uint8_t *data, int min_len) if (end < min_len) { end = min_len; } - chrp_nvram_finish_partition(part_header, end); - + if (!dry_run) { + chrp_nvram_finish_partition(part_header, end); + } return end; } diff --git a/hw/nvram/mac_nvram.c b/hw/nvram/mac_nvram.c index beec1c4e4d11..4396f893f14a 100644 --- a/hw/nvram/mac_nvram.c +++ b/hw/nvram/mac_nvram.c @@ -141,7 +141,7 @@ static void pmac_format_nvram_partition_of(MacIONVRAMState *nvr, int off, /* OpenBIOS nvram variables partition */ sysp_end = chrp_nvram_create_system_partition(&nvr->data[off], - DEF_SYSTEM_SIZE) + off; + DEF_SYSTEM_SIZE, false) + off; /* Free space partition */ chrp_nvram_create_free_partition(&nvr->data[sysp_end], len - sysp_end); diff --git a/hw/nvram/spapr_nvram.c b/hw/nvram/spapr_nvram.c index 15d08281d411..992b818d34e7 100644 --- a/hw/nvram/spapr_nvram.c +++ b/hw/nvram/spapr_nvram.c @@ -188,7 +188,8 @@ static void spapr_nvram_realize(SpaprVioDevice *dev, Error **errp) } } else if (nb_prom_envs > 0) { /* Create a system partition to pass the -prom-env variables */ - chrp_nvram_create_system_partition(nvram->buf, MIN_NVRAM_SIZE / 4); + chrp_nvram_create_system_partition(nvram->buf, MIN_NVRAM_SIZE / 4, + false); chrp_nvram_create_free_partition(&nvram->buf[MIN_NVRAM_SIZE / 4], nvram->size - MIN_NVRAM_SIZE / 4); } diff --git a/hw/sparc/sun4m.c b/hw/sparc/sun4m.c index 9be930415f8e..61804ccd4286 100644 --- a/hw/sparc/sun4m.c +++ b/hw/sparc/sun4m.c @@ -143,7 +143,7 @@ static void nvram_init(Nvram *nvram, uint8_t *macaddr, memset(image, '\0', sizeof(image)); /* OpenBIOS nvram variables partition */ - sysp_end = chrp_nvram_create_system_partition(image, 0); + sysp_end = chrp_nvram_create_system_partition(image, 0, false); /* Free space partition */ chrp_nvram_create_free_partition(&image[sysp_end], 0x1fd0 - sysp_end); diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c index 9e30203dcc44..2409e739e81b 100644 --- a/hw/sparc64/sun4u.c +++ b/hw/sparc64/sun4u.c @@ -136,7 +136,7 @@ static int sun4u_NVRAM_set_params(Nvram *nvram, uint16_t NVRAM_size, memset(image, '\0', sizeof(image)); /* OpenBIOS nvram variables partition */ - sysp_end = chrp_nvram_create_system_partition(image, 0); + sysp_end = chrp_nvram_create_system_partition(image, 0, false); /* Free space partition */ chrp_nvram_create_free_partition(&image[sysp_end], 0x1fd0 - sysp_end); diff --git a/include/hw/nvram/chrp_nvram.h b/include/hw/nvram/chrp_nvram.h index 09941a9be454..1d32dbf61331 100644 --- a/include/hw/nvram/chrp_nvram.h +++ b/include/hw/nvram/chrp_nvram.h @@ -50,7 +50,8 @@ chrp_nvram_finish_partition(ChrpNvramPartHdr *header, uint32_t size) header->checksum = sum & 0xff; } -int chrp_nvram_create_system_partition(uint8_t *data, int min_len); +int chrp_nvram_create_system_partition(uint8_t *data, int min_len, + bool dry_run); int chrp_nvram_create_free_partition(uint8_t *data, int len); #endif