Re: [PATCH 7/7] hw/riscv/virt.c: use g_autofree in create_fdt_*

[Alistair Francis]

On Tue, Jan 23, 2024 at 8:18 AM Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
> We have a lot of cases where a char or an uint32_t pointer is used once
> to alloc a string/array, read/written during the function, and then
> g_free() at the end. There's no pointer re-use - a single alloc, a
> single g_free().
>
> Use 'g_autofree' to avoid the g_free() calls.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  hw/riscv/virt.c | 78 ++++++++++++++-----------------------------------
>  1 file changed, 22 insertions(+), 56 deletions(-)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 710fbbda2c..1c257e89d2 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -285,7 +285,7 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int 
> socket,
>  static void create_fdt_socket_memory(RISCVVirtState *s,
>                                       const MemMapEntry *memmap, int socket)
>  {
> -    char *mem_name;
> +    g_autofree char *mem_name = NULL;
>      uint64_t addr, size;
>      MachineState *ms = MACHINE(s);
>
> @@ -297,7 +297,6 @@ static void create_fdt_socket_memory(RISCVVirtState *s,
>          addr >> 32, addr, size >> 32, size);
>      qemu_fdt_setprop_string(ms->fdt, mem_name, "device_type", "memory");
>      riscv_socket_fdt_write_id(ms, mem_name, socket);
> -    g_free(mem_name);
>  }
>
>  static void create_fdt_socket_clint(RISCVVirtState *s,
> @@ -305,8 +304,8 @@ static void create_fdt_socket_clint(RISCVVirtState *s,
>                                      uint32_t *intc_phandles)
>  {
>      int cpu;
> -    char *clint_name;
> -    uint32_t *clint_cells;
> +    g_autofree char *clint_name = NULL;
> +    g_autofree uint32_t *clint_cells = NULL;
>      unsigned long clint_addr;
>      MachineState *ms = MACHINE(s);
>      static const char * const clint_compat[2] = {
> @@ -333,9 +332,6 @@ static void create_fdt_socket_clint(RISCVVirtState *s,
>      qemu_fdt_setprop(ms->fdt, clint_name, "interrupts-extended",
>          clint_cells, s->soc[socket].num_harts * sizeof(uint32_t) * 4);
>      riscv_socket_fdt_write_id(ms, clint_name, socket);
> -    g_free(clint_name);
> -
> -    g_free(clint_cells);
>  }
>
>  static void create_fdt_socket_aclint(RISCVVirtState *s,
> @@ -346,9 +342,9 @@ static void create_fdt_socket_aclint(RISCVVirtState *s,
>      char *name;
>      unsigned long addr, size;
>      uint32_t aclint_cells_size;
> -    uint32_t *aclint_mswi_cells;
> -    uint32_t *aclint_sswi_cells;
> -    uint32_t *aclint_mtimer_cells;
> +    g_autofree uint32_t *aclint_mswi_cells = NULL;
> +    g_autofree uint32_t *aclint_sswi_cells = NULL;
> +    g_autofree uint32_t *aclint_mtimer_cells = NULL;
>      MachineState *ms = MACHINE(s);
>
>      aclint_mswi_cells = g_new0(uint32_t, s->soc[socket].num_harts * 2);
> @@ -420,10 +416,6 @@ static void create_fdt_socket_aclint(RISCVVirtState *s,
>          riscv_socket_fdt_write_id(ms, name, socket);
>          g_free(name);
>      }
> -
> -    g_free(aclint_mswi_cells);
> -    g_free(aclint_mtimer_cells);
> -    g_free(aclint_sswi_cells);
>  }
>
>  static void create_fdt_socket_plic(RISCVVirtState *s,
> @@ -432,8 +424,8 @@ static void create_fdt_socket_plic(RISCVVirtState *s,
>                                     uint32_t *plic_phandles)
>  {
>      int cpu;
> -    char *plic_name;
> -    uint32_t *plic_cells;
> +    g_autofree char *plic_name = NULL;
> +    g_autofree uint32_t *plic_cells;
>      unsigned long plic_addr;
>      MachineState *ms = MACHINE(s);
>      static const char * const plic_compat[2] = {
> @@ -493,10 +485,6 @@ static void create_fdt_socket_plic(RISCVVirtState *s,
>                                         memmap[VIRT_PLATFORM_BUS].size,
>                                         VIRT_PLATFORM_BUS_IRQ);
>      }
> -
> -    g_free(plic_name);
> -
> -    g_free(plic_cells);
>  }
>
>  uint32_t imsic_num_bits(uint32_t count)
> @@ -515,11 +503,12 @@ static void create_fdt_one_imsic(RISCVVirtState *s, 
> hwaddr base_addr,
>                                   bool m_mode, uint32_t imsic_guest_bits)
>  {
>      int cpu, socket;
> -    char *imsic_name;
> +    g_autofree char *imsic_name = NULL;
>      MachineState *ms = MACHINE(s);
>      int socket_count = riscv_socket_count(ms);
> -    uint32_t imsic_max_hart_per_socket;
> -    uint32_t *imsic_cells, *imsic_regs, imsic_addr, imsic_size;
> +    uint32_t imsic_max_hart_per_socket, imsic_addr, imsic_size;
> +    g_autofree uint32_t *imsic_cells = NULL;
> +    g_autofree uint32_t *imsic_regs = NULL;
>
>      imsic_cells = g_new0(uint32_t, ms->smp.cpus * 2);
>      imsic_regs = g_new0(uint32_t, socket_count * 4);
> @@ -571,10 +560,6 @@ static void create_fdt_one_imsic(RISCVVirtState *s, 
> hwaddr base_addr,
>                                IMSIC_MMIO_GROUP_MIN_SHIFT);
>      }
>      qemu_fdt_setprop_cell(ms->fdt, imsic_name, "phandle", msi_phandle);
> -
> -    g_free(imsic_name);
> -    g_free(imsic_regs);
> -    g_free(imsic_cells);
>  }
>
>  static void create_fdt_imsic(RISCVVirtState *s, const MemMapEntry *memmap,
> @@ -606,12 +591,10 @@ static void create_fdt_one_aplic(RISCVVirtState *s, int 
> socket,
>                                   bool m_mode, int num_harts)
>  {
>      int cpu;
> -    char *aplic_name;
> -    uint32_t *aplic_cells;
> +    g_autofree char *aplic_name = NULL;
> +    g_autofree uint32_t *aplic_cells = g_new0(uint32_t, num_harts * 2);
>      MachineState *ms = MACHINE(s);
>
> -    aplic_cells = g_new0(uint32_t, num_harts * 2);
> -
>      for (cpu = 0; cpu < num_harts; cpu++) {
>          aplic_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
>          aplic_cells[cpu * 2 + 1] = cpu_to_be32(m_mode ? IRQ_M_EXT : 
> IRQ_S_EXT);
> @@ -646,9 +629,6 @@ static void create_fdt_one_aplic(RISCVVirtState *s, int 
> socket,
>
>      riscv_socket_fdt_write_id(ms, aplic_name, socket);
>      qemu_fdt_setprop_cell(ms->fdt, aplic_name, "phandle", aplic_phandle);
> -
> -    g_free(aplic_name);
> -    g_free(aplic_cells);
>  }
>
>  static void create_fdt_socket_aplic(RISCVVirtState *s,
> @@ -660,7 +640,7 @@ static void create_fdt_socket_aplic(RISCVVirtState *s,
>                                      uint32_t *aplic_phandles,
>                                      int num_harts)
>  {
> -    char *aplic_name;
> +    g_autofree char *aplic_name = NULL;
>      unsigned long aplic_addr;
>      MachineState *ms = MACHINE(s);
>      uint32_t aplic_m_phandle, aplic_s_phandle;
> @@ -695,23 +675,18 @@ static void create_fdt_socket_aplic(RISCVVirtState *s,
>                                         VIRT_PLATFORM_BUS_IRQ);
>      }
>
> -    g_free(aplic_name);
> -
>      aplic_phandles[socket] = aplic_s_phandle;
>  }
>
>  static void create_fdt_pmu(RISCVVirtState *s)
>  {
> -    char *pmu_name;
> +    g_autofree char *pmu_name = g_strdup_printf("/pmu");
>      MachineState *ms = MACHINE(s);
>      RISCVCPU hart = s->soc[0].harts[0];
>
> -    pmu_name = g_strdup_printf("/pmu");
>      qemu_fdt_add_subnode(ms->fdt, pmu_name);
>      qemu_fdt_setprop_string(ms->fdt, pmu_name, "compatible", "riscv,pmu");
>      riscv_pmu_generate_fdt_node(ms->fdt, hart.pmu_avail_ctrs, pmu_name);
> -
> -    g_free(pmu_name);
>  }
>
>  static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
> @@ -847,7 +822,7 @@ static void create_fdt_pcie(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>                              uint32_t irq_pcie_phandle,
>                              uint32_t msi_pcie_phandle)
>  {
> -    char *name;
> +    g_autofree char *name = NULL;
>      MachineState *ms = MACHINE(s);
>
>      name = g_strdup_printf("/soc/pci@%lx",
> @@ -881,7 +856,6 @@ static void create_fdt_pcie(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>          2, virt_high_pcie_memmap.base, 2, virt_high_pcie_memmap.size);
>
>      create_pcie_irq_map(s, ms->fdt, name, irq_pcie_phandle);
> -    g_free(name);
>  }
>
>  static void create_fdt_reset(RISCVVirtState *s, const MemMapEntry *memmap,
> @@ -928,7 +902,7 @@ static void create_fdt_reset(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>  static void create_fdt_uart(RISCVVirtState *s, const MemMapEntry *memmap,
>                              uint32_t irq_mmio_phandle)
>  {
> -    char *name;
> +    g_autofree char *name = NULL;
>      MachineState *ms = MACHINE(s);
>
>      name = g_strdup_printf("/soc/serial@%lx", (long)memmap[VIRT_UART0].base);
> @@ -946,13 +920,12 @@ static void create_fdt_uart(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>      }
>
>      qemu_fdt_setprop_string(ms->fdt, "/chosen", "stdout-path", name);
> -    g_free(name);
>  }
>
>  static void create_fdt_rtc(RISCVVirtState *s, const MemMapEntry *memmap,
>                             uint32_t irq_mmio_phandle)
>  {
> -    char *name;
> +    g_autofree char *name = NULL;
>      MachineState *ms = MACHINE(s);
>
>      name = g_strdup_printf("/soc/rtc@%lx", (long)memmap[VIRT_RTC].base);
> @@ -968,41 +941,36 @@ static void create_fdt_rtc(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>      } else {
>          qemu_fdt_setprop_cells(ms->fdt, name, "interrupts", RTC_IRQ, 0x4);
>      }
> -    g_free(name);
>  }
>
>  static void create_fdt_flash(RISCVVirtState *s, const MemMapEntry *memmap)
>  {
> -    char *name;
>      MachineState *ms = MACHINE(s);
>      hwaddr flashsize = virt_memmap[VIRT_FLASH].size / 2;
>      hwaddr flashbase = virt_memmap[VIRT_FLASH].base;
> +    g_autofree char *name = g_strdup_printf("/flash@%" PRIx64, flashbase);
>
> -    name = g_strdup_printf("/flash@%" PRIx64, flashbase);
>      qemu_fdt_add_subnode(ms->fdt, name);
>      qemu_fdt_setprop_string(ms->fdt, name, "compatible", "cfi-flash");
>      qemu_fdt_setprop_sized_cells(ms->fdt, name, "reg",
>                                   2, flashbase, 2, flashsize,
>                                   2, flashbase + flashsize, 2, flashsize);
>      qemu_fdt_setprop_cell(ms->fdt, name, "bank-width", 4);
> -    g_free(name);
>  }
>
>  static void create_fdt_fw_cfg(RISCVVirtState *s, const MemMapEntry *memmap)
>  {
> -    char *nodename;
>      MachineState *ms = MACHINE(s);
>      hwaddr base = memmap[VIRT_FW_CFG].base;
>      hwaddr size = memmap[VIRT_FW_CFG].size;
> +    g_autofree char *nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
>
> -    nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
>      qemu_fdt_add_subnode(ms->fdt, nodename);
>      qemu_fdt_setprop_string(ms->fdt, nodename,
>                              "compatible", "qemu,fw-cfg-mmio");
>      qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg",
>                                   2, base, 2, size);
>      qemu_fdt_setprop(ms->fdt, nodename, "dma-coherent", NULL, 0);
> -    g_free(nodename);
>  }
>
>  static void finalize_fdt(RISCVVirtState *s)
> @@ -1149,7 +1117,7 @@ static DeviceState *virt_create_plic(const MemMapEntry 
> *memmap, int socket,
>                                       int base_hartid, int hart_count)
>  {
>      DeviceState *ret;
> -    char *plic_hart_config;
> +    g_autofree char *plic_hart_config = NULL;
>
>      /* Per-socket PLIC hart topology configuration string */
>      plic_hart_config = riscv_plic_hart_config_string(hart_count);
> @@ -1168,8 +1136,6 @@ static DeviceState *virt_create_plic(const MemMapEntry 
> *memmap, int socket,
>              VIRT_PLIC_CONTEXT_STRIDE,
>              memmap[VIRT_PLIC].size);
>
> -    g_free(plic_hart_config);
> -
>      return ret;
>  }
>
> --
> 2.43.0
>
>