[Qemu-devel] [PATCH] RISC-V: Fix a memory leak when realizing a sifive_e

[Palmer Dabbelt]

Coverity pointed out a memory leak in riscv_sifive_e_soc_realize(),
where a pair of recently added MemoryRegion instances would not be freed
if there were errors elsewhere in the function.  The fix here is to
simply not use dynamic allocation for these instances: there's always
one of each in SiFiveESoCState, so instead we just include them within
the struct.

Thanks to Peter for pointing out the bug and suggesting the fix!

Fixes: 30efbf330a45 ("SiFive RISC-V GPIO Device")
Signed-off-by: Palmer Dabbelt <pal...@sifive.com>
---
 hw/riscv/sifive_e.c         | 12 +++++-------
 include/hw/riscv/sifive_e.h |  2 ++
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/hw/riscv/sifive_e.c b/hw/riscv/sifive_e.c
index 80ac56fa7d5e..83375afcd1d6 100644
--- a/hw/riscv/sifive_e.c
+++ b/hw/riscv/sifive_e.c
@@ -158,17 +158,15 @@ static void riscv_sifive_e_soc_realize(DeviceState *dev, 
Error **errp)
 
     SiFiveESoCState *s = RISCV_E_SOC(dev);
     MemoryRegion *sys_mem = get_system_memory();
-    MemoryRegion *xip_mem = g_new(MemoryRegion, 1);
-    MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
 
     object_property_set_bool(OBJECT(&s->cpus), true, "realized",
                             &error_abort);
 
     /* Mask ROM */
-    memory_region_init_rom(mask_rom, NULL, "riscv.sifive.e.mrom",
+    memory_region_init_rom(&s->mask_rom, NULL, "riscv.sifive.e.mrom",
         memmap[SIFIVE_E_MROM].size, &error_fatal);
     memory_region_add_subregion(sys_mem,
-        memmap[SIFIVE_E_MROM].base, mask_rom);
+        memmap[SIFIVE_E_MROM].base, &s->mask_rom);
 
     /* MMIO */
     s->plic = sifive_plic_create(memmap[SIFIVE_E_PLIC].base,
@@ -228,10 +226,10 @@ static void riscv_sifive_e_soc_realize(DeviceState *dev, 
Error **errp)
         memmap[SIFIVE_E_PWM2].base, memmap[SIFIVE_E_PWM2].size);
 
     /* Flash memory */
-    memory_region_init_ram(xip_mem, NULL, "riscv.sifive.e.xip",
+    memory_region_init_ram(&s->xip_mem, NULL, "riscv.sifive.e.xip",
         memmap[SIFIVE_E_XIP].size, &error_fatal);
-    memory_region_set_readonly(xip_mem, true);
-    memory_region_add_subregion(sys_mem, memmap[SIFIVE_E_XIP].base, xip_mem);
+    memory_region_set_readonly(&s->xip_mem, true);
+    memory_region_add_subregion(sys_mem, memmap[SIFIVE_E_XIP].base, 
&s->xip_mem);
 }
 
 static void riscv_sifive_e_machine_init(MachineClass *mc)
diff --git a/include/hw/riscv/sifive_e.h b/include/hw/riscv/sifive_e.h
index 3b14eb74621f..d175b24cb209 100644
--- a/include/hw/riscv/sifive_e.h
+++ b/include/hw/riscv/sifive_e.h
@@ -33,6 +33,8 @@ typedef struct SiFiveESoCState {
     RISCVHartArrayState cpus;
     DeviceState *plic;
     SIFIVEGPIOState gpio;
+    MemoryRegion xip_mem;
+    MemoryRegion mask_rom;
 } SiFiveESoCState;
 
 typedef struct SiFiveEState {
-- 
2.21.0