diff options
| -rw-r--r-- | kexec/arch/arm64/kexec-arm64.c | 138 |
1 files changed, 100 insertions, 38 deletions
diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c index 62f3758..a206c17 100644 --- a/kexec/arch/arm64/kexec-arm64.c +++ b/kexec/arch/arm64/kexec-arm64.c @@ -15,6 +15,11 @@ #include <linux/elf-em.h> #include <elf.h> +#include <unistd.h> +#include <syscall.h> +#include <errno.h> +#include <linux/random.h> + #include "kexec.h" #include "kexec-arm64.h" #include "crashdump.h" @@ -392,11 +397,13 @@ static int fdt_setprop_range(void *fdt, int nodeoffset, static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) { uint32_t address_cells, size_cells; - int range_len; - int nodeoffset; + uint64_t fdt_val64; + uint64_t *prop; char *new_buf = NULL; + int len, range_len; + int nodeoffset; int new_size; - int result; + int result, kaslr_seed; result = fdt_check_header(dtb->buf); @@ -407,47 +414,103 @@ static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) result = set_bootargs(dtb, command_line); - if (on_crash) { - /* determine #address-cells and #size-cells */ - result = get_cells_size(dtb->buf, &address_cells, &size_cells); - if (result) { - fprintf(stderr, - "kexec: cannot determine cells-size.\n"); - result = -EINVAL; - goto on_error; - } + /* determine #address-cells and #size-cells */ + result = get_cells_size(dtb->buf, &address_cells, &size_cells); + if (result) { + fprintf(stderr, "kexec: cannot determine cells-size.\n"); + result = -EINVAL; + goto on_error; + } - if (!cells_size_fitted(address_cells, size_cells, - &elfcorehdr_mem)) { - fprintf(stderr, - "kexec: elfcorehdr doesn't fit cells-size.\n"); + if (!cells_size_fitted(address_cells, size_cells, + &elfcorehdr_mem)) { + fprintf(stderr, "kexec: elfcorehdr doesn't fit cells-size.\n"); + result = -EINVAL; + goto on_error; + } + + if (!cells_size_fitted(address_cells, size_cells, + &crash_reserved_mem)) { + fprintf(stderr, "kexec: usable memory range doesn't fit cells-size.\n"); + result = -EINVAL; + goto on_error; + } + + /* duplicate dt blob */ + range_len = sizeof(uint32_t) * (address_cells + size_cells); + new_size = fdt_totalsize(dtb->buf) + + fdt_prop_len(PROP_ELFCOREHDR, range_len) + + fdt_prop_len(PROP_USABLE_MEM_RANGE, range_len); + + new_buf = xmalloc(new_size); + result = fdt_open_into(dtb->buf, new_buf, new_size); + if (result) { + dbgprintf("%s: fdt_open_into failed: %s\n", __func__, + fdt_strerror(result)); + result = -ENOSPC; + goto on_error; + } + + /* fixup 'kaslr-seed' with a random value, if supported */ + nodeoffset = fdt_path_offset(new_buf, "/chosen"); + prop = fdt_getprop_w(new_buf, nodeoffset, + "kaslr-seed", &len); + if (!prop || len != sizeof(uint64_t)) { + dbgprintf("%s: no kaslr-seed found\n", + __func__); + /* for kexec warm reboot case, we don't need to fixup + * other dtb properties + */ + if (!on_crash) { + dump_reservemap(dtb); + if (new_buf) + free(new_buf); + + return result; + } + } else { + kaslr_seed = fdt64_to_cpu(*prop); + + /* kaslr_seed must be wiped clean by primary + * kernel during boot + */ + if (kaslr_seed != 0) { + dbgprintf("%s: kaslr-seed is not wiped to 0.\n", + __func__); result = -EINVAL; goto on_error; } - if (!cells_size_fitted(address_cells, size_cells, - &crash_reserved_mem)) { - fprintf(stderr, - "kexec: usable memory range doesn't fit cells-size.\n"); + /* + * Invoke the getrandom system call with + * GRND_NONBLOCK, to make sure we + * have a valid random seed to pass to the + * secondary kernel. + */ + result = syscall(SYS_getrandom, &fdt_val64, + sizeof(fdt_val64), + GRND_NONBLOCK); + + if(result == -1) { + dbgprintf("%s: Reading random bytes failed.\n", + __func__); result = -EINVAL; goto on_error; } - /* duplicate dt blob */ - range_len = sizeof(uint32_t) * (address_cells + size_cells); - new_size = fdt_totalsize(dtb->buf) - + fdt_prop_len(PROP_ELFCOREHDR, range_len) - + fdt_prop_len(PROP_USABLE_MEM_RANGE, range_len); - - new_buf = xmalloc(new_size); - result = fdt_open_into(dtb->buf, new_buf, new_size); + nodeoffset = fdt_path_offset(new_buf, "/chosen"); + result = fdt_setprop_inplace(new_buf, + nodeoffset, "kaslr-seed", + &fdt_val64, sizeof(fdt_val64)); if (result) { - dbgprintf("%s: fdt_open_into failed: %s\n", __func__, - fdt_strerror(result)); - result = -ENOSPC; + dbgprintf("%s: fdt_setprop failed: %s\n", + __func__, fdt_strerror(result)); + result = -EINVAL; goto on_error; } + } + if (on_crash) { /* add linux,elfcorehdr */ nodeoffset = fdt_path_offset(new_buf, "/chosen"); result = fdt_setprop_range(new_buf, nodeoffset, @@ -455,7 +518,7 @@ static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) address_cells, size_cells); if (result) { dbgprintf("%s: fdt_setprop failed: %s\n", __func__, - fdt_strerror(result)); + fdt_strerror(result)); result = -EINVAL; goto on_error; } @@ -467,18 +530,17 @@ static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) address_cells, size_cells); if (result) { dbgprintf("%s: fdt_setprop failed: %s\n", __func__, - fdt_strerror(result)); + fdt_strerror(result)); result = -EINVAL; goto on_error; } - - fdt_pack(new_buf); - dtb->buf = new_buf; - dtb->size = fdt_totalsize(new_buf); } - dump_reservemap(dtb); + fdt_pack(new_buf); + dtb->buf = new_buf; + dtb->size = fdt_totalsize(new_buf); + dump_reservemap(dtb); return result; |