qemu-e2k/hw/xtensa/sim.c
Markus Armbruster f8ed85ac99 Fix bad error handling after memory_region_init_ram()
Symptom:

    $ qemu-system-x86_64 -m 10000000
    Unexpected error in ram_block_add() at /work/armbru/qemu/exec.c:1456:
    upstream-qemu: cannot set up guest memory 'pc.ram': Cannot allocate memory
    Aborted (core dumped)

Root cause: commit ef701d7 screwed up handling of out-of-memory
conditions.  Before the commit, we report the error and exit(1), in
one place, ram_block_add().  The commit lifts the error handling up
the call chain some, to three places.  Fine.  Except it uses
&error_abort in these places, changing the behavior from exit(1) to
abort(), and thus undoing the work of commit 3922825 "exec: Don't
abort when we can't allocate guest memory".

The three places are:

* memory_region_init_ram()

  Commit 4994653 (right after commit ef701d7) lifted the error
  handling further, through memory_region_init_ram(), multiplying the
  incorrect use of &error_abort.  Later on, imitation of existing
  (bad) code may have created more.

* memory_region_init_ram_ptr()

  The &error_abort is still there.

* memory_region_init_rom_device()

  Doesn't need fixing, because commit 33e0eb5 (soon after commit
  ef701d7) lifted the error handling further, and in the process
  changed it from &error_abort to passing it up the call chain.
  Correct, because the callers are realize() methods.

Fix the error handling after memory_region_init_ram() with a
Coccinelle semantic patch:

    @r@
    expression mr, owner, name, size, err;
    position p;
    @@
            memory_region_init_ram(mr, owner, name, size,
    (
    -                              &error_abort
    +                              &error_fatal
    |
                                   err@p
    )
                                  );
    @script:python@
        p << r.p;
    @@
    print "%s:%s:%s" % (p[0].file, p[0].line, p[0].column)

When the last argument is &error_abort, it gets replaced by
&error_fatal.  This is the fix.

If the last argument is anything else, its position is reported.  This
lets us check the fix is complete.  Four positions get reported:

* ram_backend_memory_alloc()

  Error is passed up the call chain, ultimately through
  user_creatable_complete().  As far as I can tell, it's callers all
  handle the error sanely.

* fsl_imx25_realize(), fsl_imx31_realize(), dp8393x_realize()

  DeviceClass.realize() methods, errors handled sanely further up the
  call chain.

We're good.  Test case again behaves:

    $ qemu-system-x86_64 -m 10000000
    qemu-system-x86_64: cannot set up guest memory 'pc.ram': Cannot allocate memory
    [Exit 1 ]

The next commits will repair the rest of commit ef701d7's damage.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1441983105-26376-3-git-send-email-armbru@redhat.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
2015-09-18 14:39:29 +02:00

121 lines
4.1 KiB
C

/*
* Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Open Source and Linux Lab nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "sysemu/sysemu.h"
#include "hw/boards.h"
#include "hw/loader.h"
#include "elf.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "qemu/error-report.h"
static uint64_t translate_phys_addr(void *opaque, uint64_t addr)
{
XtensaCPU *cpu = opaque;
return cpu_get_phys_page_debug(CPU(cpu), addr);
}
static void sim_reset(void *opaque)
{
XtensaCPU *cpu = opaque;
cpu_reset(CPU(cpu));
}
static void xtensa_sim_init(MachineState *machine)
{
XtensaCPU *cpu = NULL;
CPUXtensaState *env = NULL;
MemoryRegion *ram, *rom;
ram_addr_t ram_size = machine->ram_size;
const char *cpu_model = machine->cpu_model;
const char *kernel_filename = machine->kernel_filename;
int n;
if (!cpu_model) {
cpu_model = XTENSA_DEFAULT_CPU_MODEL;
}
for (n = 0; n < smp_cpus; n++) {
cpu = cpu_xtensa_init(cpu_model);
if (cpu == NULL) {
error_report("unable to find CPU definition '%s'",
cpu_model);
exit(EXIT_FAILURE);
}
env = &cpu->env;
env->sregs[PRID] = n;
qemu_register_reset(sim_reset, cpu);
/* Need MMU initialized prior to ELF loading,
* so that ELF gets loaded into virtual addresses
*/
sim_reset(cpu);
}
ram = g_malloc(sizeof(*ram));
memory_region_init_ram(ram, NULL, "xtensa.sram", ram_size, &error_fatal);
vmstate_register_ram_global(ram);
memory_region_add_subregion(get_system_memory(), 0, ram);
rom = g_malloc(sizeof(*rom));
memory_region_init_ram(rom, NULL, "xtensa.rom", 0x1000, &error_fatal);
vmstate_register_ram_global(rom);
memory_region_add_subregion(get_system_memory(), 0xfe000000, rom);
if (kernel_filename) {
uint64_t elf_entry;
uint64_t elf_lowaddr;
#ifdef TARGET_WORDS_BIGENDIAN
int success = load_elf(kernel_filename, translate_phys_addr, cpu,
&elf_entry, &elf_lowaddr, NULL, 1, ELF_MACHINE, 0);
#else
int success = load_elf(kernel_filename, translate_phys_addr, cpu,
&elf_entry, &elf_lowaddr, NULL, 0, ELF_MACHINE, 0);
#endif
if (success > 0) {
env->pc = elf_entry;
}
}
}
static QEMUMachine xtensa_sim_machine = {
.name = "sim",
.desc = "sim machine (" XTENSA_DEFAULT_CPU_MODEL ")",
.is_default = true,
.init = xtensa_sim_init,
.max_cpus = 4,
};
static void xtensa_sim_machine_init(void)
{
qemu_register_machine(&xtensa_sim_machine);
}
machine_init(xtensa_sim_machine_init);