* [Qemu-devel] [PATCH v3 3/4] elf-loader: add more return codes
2014-02-04 4:04 [Qemu-devel] [PATCH v3 0/4] elf loader: exit if incompatible architecture is detected Alexey Kardashevskiy
2014-02-04 4:04 ` [Qemu-devel] [PATCH v3 1/4] spapr: support only ELF kernel images Alexey Kardashevskiy
2014-02-04 4:04 ` [Qemu-devel] [PATCH v3 2/4] moxie: fix load_elf() usage Alexey Kardashevskiy
@ 2014-02-04 4:04 ` Alexey Kardashevskiy
2014-02-04 4:04 ` [Qemu-devel] [PATCH v3 4/4] spapr: print more detailed error message on failed load_elf() Alexey Kardashevskiy
2014-02-06 14:45 ` [Qemu-devel] [PATCH v3 0/4] elf loader: exit if incompatible architecture is detected Alexander Graf
4 siblings, 0 replies; 6+ messages in thread
From: Alexey Kardashevskiy @ 2014-02-04 4:04 UTC (permalink / raw)
To: qemu-devel; +Cc: Alexey Kardashevskiy, qemu-ppc, Alexander Graf
The existing load_elf() just returns -1 if it fails to load ELF. However
it could be smarter than this and tell more about the failure such as
wrong endianness or incompatible platform.
This adds additional return codes for wrong architecture, wrong
endianness and if the image is not ELF at all.
This adds a load_elf_strerror() helper to convert return codes into
string messages.
This fixes handling of what load_elf() returns for s390x, other
callers just check the return value for <0 and this remains unchanged.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v3:
* added load_elf_strerror() helper
---
hw/core/loader.c | 30 ++++++++++++++++++++++++------
hw/s390x/ipl.c | 4 ++--
include/hw/elf_ops.h | 19 ++++++++++++++-----
include/hw/loader.h | 6 ++++++
4 files changed, 46 insertions(+), 13 deletions(-)
diff --git a/hw/core/loader.c b/hw/core/loader.c
index 0634bee..8a9bb5a 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -284,12 +284,30 @@ static void *load_at(int fd, int offset, int size)
#define SZ 64
#include "hw/elf_ops.h"
+const char *load_elf_strerror(int error)
+{
+ switch (error) {
+ case 0:
+ return "No error";
+ case ELF_LOAD_FAILED:
+ return "Failed to load ELF";
+ case ELF_LOAD_NOT_ELF:
+ return "The image is not ELF";
+ case ELF_LOAD_WRONG_ARCH:
+ return "The image is from incompatible architecture";
+ case ELF_LOAD_WRONG_ENDIAN:
+ return "The image has incorrect endianness";
+ default:
+ return "Unknown error";
+ }
+}
+
/* return < 0 if error, otherwise the number of bytes loaded in memory */
int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
void *translate_opaque, uint64_t *pentry, uint64_t *lowaddr,
uint64_t *highaddr, int big_endian, int elf_machine, int clear_lsb)
{
- int fd, data_order, target_data_order, must_swab, ret;
+ int fd, data_order, target_data_order, must_swab, ret = ELF_LOAD_FAILED;
uint8_t e_ident[EI_NIDENT];
fd = open(filename, O_RDONLY | O_BINARY);
@@ -302,8 +320,10 @@ int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
if (e_ident[0] != ELFMAG0 ||
e_ident[1] != ELFMAG1 ||
e_ident[2] != ELFMAG2 ||
- e_ident[3] != ELFMAG3)
+ e_ident[3] != ELFMAG3) {
+ ret = ELF_LOAD_NOT_ELF;
goto fail;
+ }
#ifdef HOST_WORDS_BIGENDIAN
data_order = ELFDATA2MSB;
#else
@@ -317,6 +337,7 @@ int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
}
if (target_data_order != e_ident[EI_DATA]) {
+ ret = ELF_LOAD_WRONG_ENDIAN;
goto fail;
}
@@ -329,12 +350,9 @@ int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
pentry, lowaddr, highaddr, elf_machine, clear_lsb);
}
- close(fd);
- return ret;
-
fail:
close(fd);
- return -1;
+ return ret;
}
static void bswap_uboot_header(uboot_image_header_t *hdr)
diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index 1a6397b..cff77ad 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -97,10 +97,10 @@ static int s390_ipl_init(SysBusDevice *dev)
} else {
kernel_size = load_elf(ipl->kernel, NULL, NULL, NULL, NULL,
NULL, 1, ELF_MACHINE, 0);
- if (kernel_size == -1) {
+ if (kernel_size < 0) {
kernel_size = load_image_targphys(ipl->kernel, 0, ram_size);
}
- if (kernel_size == -1) {
+ if (kernel_size < 0) {
fprintf(stderr, "could not load kernel '%s'\n", ipl->kernel);
return -1;
}
diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h
index acc701e..c6b5129 100644
--- a/include/hw/elf_ops.h
+++ b/include/hw/elf_ops.h
@@ -201,6 +201,7 @@ static int glue(load_elf, SZ)(const char *name, int fd,
uint64_t addr, low = (uint64_t)-1, high = 0;
uint8_t *data = NULL;
char label[128];
+ int ret = ELF_LOAD_FAILED;
if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
goto fail;
@@ -211,22 +212,30 @@ static int glue(load_elf, SZ)(const char *name, int fd,
switch (elf_machine) {
case EM_PPC64:
if (EM_PPC64 != ehdr.e_machine)
- if (EM_PPC != ehdr.e_machine)
+ if (EM_PPC != ehdr.e_machine) {
+ ret = ELF_LOAD_WRONG_ARCH;
goto fail;
+ }
break;
case EM_X86_64:
if (EM_X86_64 != ehdr.e_machine)
- if (EM_386 != ehdr.e_machine)
+ if (EM_386 != ehdr.e_machine) {
+ ret = ELF_LOAD_WRONG_ARCH;
goto fail;
+ }
break;
case EM_MICROBLAZE:
if (EM_MICROBLAZE != ehdr.e_machine)
- if (EM_MICROBLAZE_OLD != ehdr.e_machine)
+ if (EM_MICROBLAZE_OLD != ehdr.e_machine) {
+ ret = ELF_LOAD_WRONG_ARCH;
goto fail;
+ }
break;
default:
- if (elf_machine != ehdr.e_machine)
+ if (elf_machine != ehdr.e_machine) {
+ ret = ELF_LOAD_WRONG_ARCH;
goto fail;
+ }
}
if (pentry)
@@ -305,5 +314,5 @@ static int glue(load_elf, SZ)(const char *name, int fd,
fail:
g_free(data);
g_free(phdr);
- return -1;
+ return ret;
}
diff --git a/include/hw/loader.h b/include/hw/loader.h
index 7a23d6b..3f4335c 100644
--- a/include/hw/loader.h
+++ b/include/hw/loader.h
@@ -8,6 +8,12 @@ int get_image_size(const char *filename);
int load_image(const char *filename, uint8_t *addr); /* deprecated */
int load_image_targphys(const char *filename, hwaddr,
uint64_t max_sz);
+
+#define ELF_LOAD_FAILED -1
+#define ELF_LOAD_NOT_ELF -2
+#define ELF_LOAD_WRONG_ARCH -3
+#define ELF_LOAD_WRONG_ENDIAN -4
+const char *load_elf_strerror(int error);
int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
void *translate_opaque, uint64_t *pentry, uint64_t *lowaddr,
uint64_t *highaddr, int big_endian, int elf_machine,
--
1.8.4.rc4
^ permalink raw reply related [flat|nested] 6+ messages in thread* [Qemu-devel] [PATCH v3 4/4] spapr: print more detailed error message on failed load_elf()
2014-02-04 4:04 [Qemu-devel] [PATCH v3 0/4] elf loader: exit if incompatible architecture is detected Alexey Kardashevskiy
` (2 preceding siblings ...)
2014-02-04 4:04 ` [Qemu-devel] [PATCH v3 3/4] elf-loader: add more return codes Alexey Kardashevskiy
@ 2014-02-04 4:04 ` Alexey Kardashevskiy
2014-02-06 14:45 ` [Qemu-devel] [PATCH v3 0/4] elf loader: exit if incompatible architecture is detected Alexander Graf
4 siblings, 0 replies; 6+ messages in thread
From: Alexey Kardashevskiy @ 2014-02-04 4:04 UTC (permalink / raw)
To: qemu-devel; +Cc: Alexey Kardashevskiy, qemu-ppc, Alexander Graf
This makes use of new error codes which load_elf() can return and
prints more informative error message.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
hw/ppc/spapr.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 851ce4b..c9dfc6c 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1306,15 +1306,15 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
kernel_size = load_elf(kernel_filename, translate_kernel_address, NULL,
NULL, &lowaddr, NULL, 1, ELF_MACHINE, 0);
- if (kernel_size < 0) {
+ if (kernel_size == ELF_LOAD_WRONG_ENDIAN) {
kernel_size = load_elf(kernel_filename,
translate_kernel_address, NULL,
NULL, &lowaddr, NULL, 0, ELF_MACHINE, 0);
kernel_le = kernel_size > 0;
}
if (kernel_size < 0) {
- fprintf(stderr, "qemu: could not load kernel '%s'\n",
- kernel_filename);
+ fprintf(stderr, "qemu: error loading %s: %s\n",
+ kernel_filename, load_elf_strerror(kernel_size));
exit(1);
}
--
1.8.4.rc4
^ permalink raw reply related [flat|nested] 6+ messages in thread