Replace the unsafe read-loops used in the MIPS kernel image loading
with our safe read_file() and read_in_full() wrappers.
This should fix random fails in kernel image loading, especially
from pipes and sockets.

Signed-off-by: Andre Przywara <andre.przyw...@arm.com>
---
 mips/kvm.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/mips/kvm.c b/mips/kvm.c
index d970ee0..2f0d61b 100644
--- a/mips/kvm.c
+++ b/mips/kvm.c
@@ -169,21 +169,27 @@ static bool load_flat_binary(struct kvm *kvm, int 
fd_kernel, const void *buf,
 {
        void *p;
        void *k_start;
-       int nr;
+       ssize_t kernel_size;
 
        p = k_start = guest_flat_to_host(kvm, KERNEL_LOAD_ADDR);
 
        memcpy(p, buf, buflen);
        p += buflen;
 
-       while ((nr = read(fd_kernel, p, 65536)) > 0)
-               p += nr;
+       kernel_size = read_file(fd_kernel, p,
+                               kvm->cfg.ram_size - KERNEL_LOAD_ADDR);
+       if (kernel_size == -1) {
+               if (errno == ENOMEM)
+                       die("kernel too big for guest memory");
+               else
+                       die_perror("kernel read");
+       }
 
        kvm->arch.is64bit = true;
        kvm->arch.entry_point = 0xffffffff81000000ull;
 
-       pr_info("Loaded kernel to 0x%x (%ld bytes)", KERNEL_LOAD_ADDR,
-               (long int)(p - k_start));
+       pr_info("Loaded kernel to 0x%x (%zd bytes)", KERNEL_LOAD_ADDR,
+               kernel_size);
 
        return true;
 }
@@ -199,7 +205,6 @@ static bool kvm__arch_get_elf_64_info(Elf64_Ehdr *ehdr, int 
fd_kernel,
                                      struct kvm__arch_elf_info *ei)
 {
        int i;
-       size_t nr;
        Elf64_Phdr phdr;
 
        if (ehdr->e_phentsize != sizeof(phdr)) {
@@ -214,8 +219,7 @@ static bool kvm__arch_get_elf_64_info(Elf64_Ehdr *ehdr, int 
fd_kernel,
 
        phdr.p_type = PT_NULL;
        for (i = 0; i < ehdr->e_phnum; i++) {
-               nr = read(fd_kernel, &phdr, sizeof(phdr));
-               if (nr != sizeof(phdr)) {
+               if (read_in_full(fd_kernel, &phdr, sizeof(phdr)) != 
sizeof(phdr)) {
                        pr_info("Couldn't read %d bytes for ELF PHDR.", 
(int)sizeof(phdr));
                        return false;
                }
@@ -245,7 +249,6 @@ static bool kvm__arch_get_elf_32_info(Elf32_Ehdr *ehdr, int 
fd_kernel,
                                      struct kvm__arch_elf_info *ei)
 {
        int i;
-       size_t nr;
        Elf32_Phdr phdr;
 
        if (ehdr->e_phentsize != sizeof(phdr)) {
@@ -260,8 +263,7 @@ static bool kvm__arch_get_elf_32_info(Elf32_Ehdr *ehdr, int 
fd_kernel,
 
        phdr.p_type = PT_NULL;
        for (i = 0; i < ehdr->e_phnum; i++) {
-               nr = read(fd_kernel, &phdr, sizeof(phdr));
-               if (nr != sizeof(phdr)) {
+               if (read_in_full(fd_kernel, &phdr, sizeof(phdr)) != 
sizeof(phdr)) {
                        pr_info("Couldn't read %d bytes for ELF PHDR.", 
(int)sizeof(phdr));
                        return false;
                }
@@ -292,7 +294,6 @@ union ElfHeaders {
 static bool load_elf_binary(struct kvm *kvm, int fd_kernel,
                            union ElfHeaders *eh)
 {
-       size_t nr;
        char *p;
        struct kvm__arch_elf_info ei;
 
@@ -331,13 +332,9 @@ static bool load_elf_binary(struct kvm *kvm, int fd_kernel,
        pr_info("ELF Loading 0x%lx bytes from 0x%llx to 0x%llx",
                (unsigned long)ei.len, (unsigned long long)ei.offset,
                (unsigned long long)ei.load_addr);
-       do {
-               nr = read(fd_kernel, p, ei.len);
-               if (nr < 0)
-                       die_perror("read");
-               p += nr;
-               ei.len -= nr;
-       } while (ei.len);
+
+       if (read_in_full(fd_kernel, p, ei.len) != (ssize_t)ei.len)
+               die_perror("read");
 
        return true;
 }
-- 
2.3.5

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