[Intel-gfx] [igt-dev] [PATCH v2 i-g-t] lib/intel_mmio: Fix mmapped resources not unmapped on fini
Kamil Konieczny
kamil.konieczny at linux.intel.com
Fri Mar 4 15:14:05 UTC 2022
Hi Janusz,
Dnia 2022-03-01 at 15:07:55 +0100, Janusz Krzysztofik napisał(a):
> Commit 5f3cfa485eb4 ("lib: Use safe wrappers around libpciaccess
> initialization functions") took care of not leaking memory allocated by
> pci_system_init() but didn't take care of users potentially attempting to
> reinitialize global data maintained by libpciaccess. For example,
> intel_register_access_init() mmaps device's PCI BAR0 resource with
> pci_device_map_range() but intel_register_access_fini() doesn't unmap it
> and next call to intel_register_access_init() fails on attempt to mmap it
> again with pci_device_map_range().
------ ^
imho you can cut here, no need to repeat it twice.
>
> Fix it, and also provide intel_mmio_umap_*() counterparts to public
-------------------------------------- ^
s/umap/unmap/
> functions intel_mmio_use_pci_bar() and intel_mmio_use_dump_file().
>
> v2: apply last minute fixes, cached but unfortunately not committed before
> sending
>
> Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
> ---
> lib/intel_io.h | 4 +++
> lib/intel_mmio.c | 67 ++++++++++++++++++++++++++++++++++++++++++------
> 2 files changed, 63 insertions(+), 8 deletions(-)
>
> diff --git a/lib/intel_io.h b/lib/intel_io.h
> index 1cfe4fb6b9..ea2649d9bc 100644
> --- a/lib/intel_io.h
> +++ b/lib/intel_io.h
> @@ -49,6 +49,8 @@ struct intel_register_map {
>
> struct intel_mmio_data {
> void *igt_mmio;
> + size_t mmio_size;
> + struct pci_device *dev;
> struct intel_register_map map;
> uint32_t pci_device_id;
> int key;
> @@ -57,7 +59,9 @@ struct intel_mmio_data {
>
> void intel_mmio_use_pci_bar(struct intel_mmio_data *mmio_data,
> struct pci_device *pci_dev);
> +void intel_mmio_unmap_pci_bar(struct intel_mmio_data *mmio_data);
> void intel_mmio_use_dump_file(struct intel_mmio_data *mmio_data, char *file);
> +void intel_mmio_unmap_dump_file(struct intel_mmio_data *mmio_data);
>
> int intel_register_access_init(struct intel_mmio_data *mmio_data,
> struct pci_device *pci_dev, int safe, int fd);
> diff --git a/lib/intel_mmio.c b/lib/intel_mmio.c
> index 667a69f5aa..cb8f9db2e5 100644
> --- a/lib/intel_mmio.c
> +++ b/lib/intel_mmio.c
> @@ -82,6 +82,8 @@ void *igt_global_mmio;
> * Sets also up mmio_data->igt_mmio to point at the data contained
> * in @file. This allows the same code to get reused for dumping and decoding
> * from running hardware as from register dumps.
> + *
> + * Users are expected to call intel_mmio_unmap_dump_file() after use.
> */
> void
> intel_mmio_use_dump_file(struct intel_mmio_data *mmio_data, char *file)
> @@ -99,11 +101,29 @@ intel_mmio_use_dump_file(struct intel_mmio_data *mmio_data, char *file)
imho at beginning of this function there should be check
that igt_global_mmio == NULL, and the same check should be at
other init functions.
Looks like we cannot mmap two different pcie cards at the same
time with this lib.
> igt_fail_on_f(mmio_data->igt_mmio == MAP_FAILED,
> "Couldn't mmap %s\n", file);
>
> + mmio_data->mmio_size = st.st_size;
> igt_global_mmio = mmio_data->igt_mmio;
>
> close(fd);
> }
>
> +/**
> + * intel_mmio_unmap_dump_file:
> + * @mmio_data: mmio structure for IO operations
> + *
> + * Unmaps a dump file mmapped with intel_mmio_use_dump_file()
> + */
> +void intel_mmio_unmap_dump_file(struct intel_mmio_data *mmio_data)
> +{
> + if (igt_warn_on_f(!mmio_data->mmio_size || mmio_data->dev,
> + "test bug: argument doesn't point to struct intel_mmio_data initialized with intel_mmio_use_dump_file()\n"))
Please shorten text for warning, something like: arg was not
inialized with ...
Please also add check for null at global var.
> + return;
> +
> + igt_global_mmio = NULL;
> + igt_debug_on(munmap(mmio_data->igt_mmio, mmio_data->mmio_size) < 0);
> + mmio_data->mmio_size = 0;
> +}
> +
> /**
> * intel_mmio_use_pci_bar:
> * @mmio_data: mmio structure for IO operations
> @@ -112,12 +132,14 @@ intel_mmio_use_dump_file(struct intel_mmio_data *mmio_data, char *file)
> * Fill a mmio_data stucture with igt_mmio to point at the mmio bar.
> *
> * @pci_dev can be obtained from intel_get_pci_device().
> + *
> + * Users are expected to call intel_mmio_unmap_pci_bar() after use.
> */
> void
> intel_mmio_use_pci_bar(struct intel_mmio_data *mmio_data, struct pci_device *pci_dev)
> {
> uint32_t devid, gen;
> - int mmio_bar, mmio_size;
> + int mmio_bar;
Please use this local var and assign it to struct only after
succesfull initialization.
> int error;
>
> memset(mmio_data, 0, sizeof(struct intel_mmio_data));
> @@ -129,22 +151,42 @@ intel_mmio_use_pci_bar(struct intel_mmio_data *mmio_data, struct pci_device *pci
>
> gen = intel_gen(devid);
> if (gen < 3)
> - mmio_size = 512*1024;
> + mmio_data->mmio_size = 512*1024;
> else if (gen < 5)
> - mmio_size = 512*1024;
> + mmio_data->mmio_size = 512*1024;
Both places uses the same number 512*1024, please make it one
if check: if (gen < 5)
Or maybe it is an error for gen < 3 ?
> else
> - mmio_size = 2*1024*1024;
> + mmio_data->mmio_size = 2*1024*1024;
>
> error = pci_device_map_range (pci_dev,
> pci_dev->regions[mmio_bar].base_addr,
> - mmio_size,
> + mmio_data->mmio_size,
> PCI_DEV_MAP_FLAG_WRITABLE,
> &mmio_data->igt_mmio);
>
> - igt_global_mmio = mmio_data->igt_mmio;
> -
> igt_fail_on_f(error != 0,
> "Couldn't map MMIO region\n");
> +
> + mmio_data->dev = pci_dev;
> + igt_global_mmio = mmio_data->igt_mmio;
> +}
> +
> +/**
> + * intel_mmio_unmap_pci_bar:
> + * @mmio_data: mmio structure for IO operations
> + *
> + * Unmaps a PCI BAR region mmapped with intel_mmio_use_pci_bar()
> + */
> +void intel_mmio_unmap_pci_bar(struct intel_mmio_data *mmio_data)
> +{
> + if (igt_warn_on_f(!mmio_data->dev,
> + "test bug: argument doesn't point to struct intel_mmio_data initialized with intel_mmio_use_pci_bar()\n"))
Same here, please shorten this warn.
> + return;
> +
> + igt_global_mmio = NULL;
> + igt_debug_on(pci_device_unmap_range(mmio_data->dev,
> + mmio_data->igt_mmio, mmio_data->mmio_size) < 0);
> + mmio_data->dev = NULL;
> + mmio_data->mmio_size = 0;
> }
>
> static void
> @@ -166,6 +208,8 @@ release_forcewake_lock(int fd)
> * It also initializes mmio_data->igt_mmio like intel_mmio_use_pci_bar().
> *
> * @pci_dev can be obtained from intel_get_pci_device().
> + *
> + * Users are expected to call intel_register_access_fini() after use.
> */
> int
> intel_register_access_init(struct intel_mmio_data *mmio_data, struct pci_device *pci_dev, int safe, int fd)
> @@ -222,8 +266,15 @@ int intel_register_access_needs_fakewake(struct intel_mmio_data *mmio_data)
> void
> intel_register_access_fini(struct intel_mmio_data *mmio_data)
> {
> - if (mmio_data->key && intel_register_access_needs_wake(mmio_data))
> + if (igt_warn_on_f(!mmio_data->key,
> + "test bug: argument doesn't point to struct intel_mmio_data initialized with intel_register_access_init()\n"))
Same here, please shorten this warn.
Btw, in this lib error condition for key is -1, so maybe this
should also be cheked ?
> + return;
> +
> + if (intel_register_access_needs_wake(mmio_data))
> release_forcewake_lock(mmio_data->key);
> + mmio_data->key = 0;
> +
> + intel_mmio_unmap_pci_bar(mmio_data);
> }
>
> /**
> --
> 2.25.1
>
Please correct desciption of global var igt_global_mmio, there
is one more method for initialize it: intel_mmio_use_pci_bar
as you wrote on irc.
Regards,
Kamil Konieczny
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