From f8ed85ac992c48814d916d5df4d44f9a971c5de4 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 11 Sep 2015 16:51:43 +0200 Subject: 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 Message-Id: <1441983105-26376-3-git-send-email-armbru@redhat.com> Reviewed-by: Peter Crosthwaite --- hw/mips/mips_fulong2e.c | 2 +- hw/mips/mips_jazz.c | 4 ++-- hw/mips/mips_malta.c | 2 +- hw/mips/mips_mipssim.c | 2 +- hw/mips/mips_r4k.c | 2 +- 5 files changed, 6 insertions(+), 6 deletions(-) (limited to 'hw/mips') diff --git a/hw/mips/mips_fulong2e.c b/hw/mips/mips_fulong2e.c index 6d2ea30..b8a11e4 100644 --- a/hw/mips/mips_fulong2e.c +++ b/hw/mips/mips_fulong2e.c @@ -294,7 +294,7 @@ static void mips_fulong2e_init(MachineState *machine) /* allocate RAM */ memory_region_allocate_system_memory(ram, NULL, "fulong2e.ram", ram_size); memory_region_init_ram(bios, NULL, "fulong2e.bios", bios_size, - &error_abort); + &error_fatal); vmstate_register_ram_global(bios); memory_region_set_readonly(bios, true); diff --git a/hw/mips/mips_jazz.c b/hw/mips/mips_jazz.c index 3906016..f944c4c 100644 --- a/hw/mips/mips_jazz.c +++ b/hw/mips/mips_jazz.c @@ -174,7 +174,7 @@ static void mips_jazz_init(MachineState *machine, memory_region_add_subregion(address_space, 0, ram); memory_region_init_ram(bios, NULL, "mips_jazz.bios", MAGNUM_BIOS_SIZE, - &error_abort); + &error_fatal); vmstate_register_ram_global(bios); memory_region_set_readonly(bios, true); memory_region_init_alias(bios2, NULL, "mips_jazz.bios", bios, @@ -241,7 +241,7 @@ static void mips_jazz_init(MachineState *machine, /* Simple ROM, so user doesn't have to provide one */ MemoryRegion *rom_mr = g_new(MemoryRegion, 1); memory_region_init_ram(rom_mr, NULL, "g364fb.rom", 0x80000, - &error_abort); + &error_fatal); vmstate_register_ram_global(rom_mr); memory_region_set_readonly(rom_mr, true); uint8_t *rom = memory_region_get_ram_ptr(rom_mr); diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c index 23b6fc3..1004e37 100644 --- a/hw/mips/mips_malta.c +++ b/hw/mips/mips_malta.c @@ -1120,7 +1120,7 @@ void mips_malta_init(MachineState *machine) * regions are not executable. */ memory_region_init_ram(bios_copy, NULL, "bios.1fc", BIOS_SIZE, - &error_abort); + &error_fatal); if (!rom_copy(memory_region_get_ram_ptr(bios_copy), FLASH_ADDRESS, BIOS_SIZE)) { memcpy(memory_region_get_ram_ptr(bios_copy), diff --git a/hw/mips/mips_mipssim.c b/hw/mips/mips_mipssim.c index 61f74a6..063151f 100644 --- a/hw/mips/mips_mipssim.c +++ b/hw/mips/mips_mipssim.c @@ -174,7 +174,7 @@ mips_mipssim_init(MachineState *machine) memory_region_allocate_system_memory(ram, NULL, "mips_mipssim.ram", ram_size); memory_region_init_ram(bios, NULL, "mips_mipssim.bios", BIOS_SIZE, - &error_abort); + &error_fatal); vmstate_register_ram_global(bios); memory_region_set_readonly(bios, true); diff --git a/hw/mips/mips_r4k.c b/hw/mips/mips_r4k.c index 86b2c0b..c961227 100644 --- a/hw/mips/mips_r4k.c +++ b/hw/mips/mips_r4k.c @@ -233,7 +233,7 @@ void mips_r4k_init(MachineState *machine) if ((bios_size > 0) && (bios_size <= BIOS_SIZE)) { bios = g_new(MemoryRegion, 1); memory_region_init_ram(bios, NULL, "mips_r4k.bios", BIOS_SIZE, - &error_abort); + &error_fatal); vmstate_register_ram_global(bios); memory_region_set_readonly(bios, true); memory_region_add_subregion(get_system_memory(), 0x1fc00000, bios); -- cgit v1.1