| Message ID | 20201204195149.611-4-nramas@linux.microsoft.com |
|---|---|
| State | New |
| Headers | show |
| Series | Carry forward IMA measurement log on kexec on ARM64 | expand |
Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes: > The functions do_get_kexec_buffer() and get_addr_size_cells(), > defined in arch/powerpc/kexec/ima.c, retrieve the address and size > of the given property from the device tree blob. These functions do > not have architecture specific code, but are currently limited to > powerpc. do_get_kexec_buffer() correctly handles a device tree property > that is a child node of the root node, but not anything other than > the immediate root child nodes. > > Move architecture independent functions get_ima_kexec_buffer() and > get_root_addr_size_cells() to "drivers/of/kexec.c". These functions > retrieve the chosen node "linux,ima-kexec-buffer" from the device tree, > and return the address and size of the buffer used for carrying forward > the IMA measurement log across kexec system call. > > Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com> > Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com> > Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> I'd personally squash this patch with the next one, but I'll leave it just as a suggestion since maintainers are the ones who know best what works well in this regard. The code is good, except for a nit below: Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> > --- > drivers/of/kexec.c | 70 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/kexec.h | 3 ++ > 2 files changed, 73 insertions(+) > > diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c > index b7d59105fcb8..516b86f7113a 100644 > --- a/drivers/of/kexec.c > +++ b/drivers/of/kexec.c > @@ -59,3 +59,73 @@ int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) > > return -ENOENT; > } > + > +/** > + * get_root_addr_size_cells - Get address and size of root node > + * > + * @addr_cells: Return address of the root node > + * @size_cells: Return size of the root node > + * > + * Return: 0 on success, or negative errno on error. > + */ > +int get_root_addr_size_cells(int *addr_cells, int *size_cells) > +{ > + struct device_node *root; > + > + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) > + return -EOPNOTSUPP; > + > + root = of_find_node_by_path("/"); > + if (!root) > + return -EINVAL; > + > + *addr_cells = of_n_addr_cells(root); > + *size_cells = of_n_size_cells(root); > + > + of_node_put(root); > + > + return 0; > +} > + > +/** > + * get_ima_kexec_buffer - Get address and size of IMA kexec buffer > + * > + * @fdt: Flattened Device Tree > + * @chosen_node: Offset of chosen node in the FDT > + * @addr: Return address of the node > + * @size: Return size of the node > + * > + * Return: 0 on success, or negative errno on error. > + */ > +int get_ima_kexec_buffer(void *fdt, int chosen_node, > + unsigned long *addr, size_t *size) > +{ > + const void *prop; > + int addr_cells, size_cells, prop_len; > + int rc; > + > + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) > + return -EOPNOTSUPP; > + > + rc = get_root_addr_size_cells(&addr_cells, &size_cells); > + if (rc) > + return rc; > + > + if (fdt) > + prop = fdt_getprop(fdt, chosen_node, > + "linux,ima-kexec-buffer", &prop_len); > + else > + prop = of_get_property(of_chosen, > + "linux,ima-kexec-buffer", &prop_len); > + > + if (!prop) > + return -ENOENT; > + > + if (prop_len < 4 * (addr_cells + size_cells)) > + return -EINVAL; > + > + *addr = of_read_number(prop, addr_cells); > + *size = of_read_number(prop + 4 * addr_cells, size_cells); > + > + return 0; > +} > diff --git a/include/linux/kexec.h b/include/linux/kexec.h > index d0234c4815da..10ff704ab670 100644 > --- a/include/linux/kexec.h > +++ b/include/linux/kexec.h > @@ -408,6 +408,9 @@ static inline int kexec_crash_loaded(void) { return 0; } > #endif /* CONFIG_KEXEC_CORE */ > > #if defined(CONFIG_OF_FLATTREE) > +extern int get_root_addr_size_cells(int *addr_cells, int *size_cells); > +extern int get_ima_kexec_buffer(void *fdt, int chosen_node, > + unsigned long *addr, size_t *size); > extern int delete_fdt_mem_rsv(void *fdt, unsigned long start, > unsigned long size); > #endif /* CONFIG_OF_FLATTREE */ The extern keyword on function prototypes doesn't have any meaning. It's better to drop them (I should have mentioned this on the previous patch as well). -- Thiago Jung Bauermann IBM Linux Technology Center
On 12/5/20 11:48 AM, Thiago Jung Bauermann wrote: > > Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes: > >> The functions do_get_kexec_buffer() and get_addr_size_cells(), >> defined in arch/powerpc/kexec/ima.c, retrieve the address and size >> of the given property from the device tree blob. These functions do >> not have architecture specific code, but are currently limited to >> powerpc. do_get_kexec_buffer() correctly handles a device tree property >> that is a child node of the root node, but not anything other than >> the immediate root child nodes. >> >> Move architecture independent functions get_ima_kexec_buffer() and >> get_root_addr_size_cells() to "drivers/of/kexec.c". These functions >> retrieve the chosen node "linux,ima-kexec-buffer" from the device tree, >> and return the address and size of the buffer used for carrying forward >> the IMA measurement log across kexec system call. >> >> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com> >> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com> >> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> > > I'd personally squash this patch with the next one, but I'll leave it > just as a suggestion since maintainers are the ones who know best what > works well in this regard. > > The code is good, except for a nit below: > > Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Thanks Thiago. I'll remove "extern" key word in function declarations when I update the patch. -lakshmi > >> --- >> drivers/of/kexec.c | 70 +++++++++++++++++++++++++++++++++++++++++++ >> include/linux/kexec.h | 3 ++ >> 2 files changed, 73 insertions(+) >> >> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c >> index b7d59105fcb8..516b86f7113a 100644 >> --- a/drivers/of/kexec.c >> +++ b/drivers/of/kexec.c >> @@ -59,3 +59,73 @@ int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) >> >> return -ENOENT; >> } >> + >> +/** >> + * get_root_addr_size_cells - Get address and size of root node >> + * >> + * @addr_cells: Return address of the root node >> + * @size_cells: Return size of the root node >> + * >> + * Return: 0 on success, or negative errno on error. >> + */ >> +int get_root_addr_size_cells(int *addr_cells, int *size_cells) >> +{ >> + struct device_node *root; >> + >> + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) >> + return -EOPNOTSUPP; >> + >> + root = of_find_node_by_path("/"); >> + if (!root) >> + return -EINVAL; >> + >> + *addr_cells = of_n_addr_cells(root); >> + *size_cells = of_n_size_cells(root); >> + >> + of_node_put(root); >> + >> + return 0; >> +} >> + >> +/** >> + * get_ima_kexec_buffer - Get address and size of IMA kexec buffer >> + * >> + * @fdt: Flattened Device Tree >> + * @chosen_node: Offset of chosen node in the FDT >> + * @addr: Return address of the node >> + * @size: Return size of the node >> + * >> + * Return: 0 on success, or negative errno on error. >> + */ >> +int get_ima_kexec_buffer(void *fdt, int chosen_node, >> + unsigned long *addr, size_t *size) >> +{ >> + const void *prop; >> + int addr_cells, size_cells, prop_len; >> + int rc; >> + >> + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) >> + return -EOPNOTSUPP; >> + >> + rc = get_root_addr_size_cells(&addr_cells, &size_cells); >> + if (rc) >> + return rc; >> + >> + if (fdt) >> + prop = fdt_getprop(fdt, chosen_node, >> + "linux,ima-kexec-buffer", &prop_len); >> + else >> + prop = of_get_property(of_chosen, >> + "linux,ima-kexec-buffer", &prop_len); >> + >> + if (!prop) >> + return -ENOENT; >> + >> + if (prop_len < 4 * (addr_cells + size_cells)) >> + return -EINVAL; >> + >> + *addr = of_read_number(prop, addr_cells); >> + *size = of_read_number(prop + 4 * addr_cells, size_cells); >> + >> + return 0; >> +} >> diff --git a/include/linux/kexec.h b/include/linux/kexec.h >> index d0234c4815da..10ff704ab670 100644 >> --- a/include/linux/kexec.h >> +++ b/include/linux/kexec.h >> @@ -408,6 +408,9 @@ static inline int kexec_crash_loaded(void) { return 0; } >> #endif /* CONFIG_KEXEC_CORE */ >> >> #if defined(CONFIG_OF_FLATTREE) >> +extern int get_root_addr_size_cells(int *addr_cells, int *size_cells); >> +extern int get_ima_kexec_buffer(void *fdt, int chosen_node, >> + unsigned long *addr, size_t *size); >> extern int delete_fdt_mem_rsv(void *fdt, unsigned long start, >> unsigned long size); >> #endif /* CONFIG_OF_FLATTREE */ > > The extern keyword on function prototypes doesn't have any meaning. > It's better to drop them (I should have mentioned this on the previous > patch as well). >
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c index b7d59105fcb8..516b86f7113a 100644 --- a/drivers/of/kexec.c +++ b/drivers/of/kexec.c @@ -59,3 +59,73 @@ int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) return -ENOENT; } + +/** + * get_root_addr_size_cells - Get address and size of root node + * + * @addr_cells: Return address of the root node + * @size_cells: Return size of the root node + * + * Return: 0 on success, or negative errno on error. + */ +int get_root_addr_size_cells(int *addr_cells, int *size_cells) +{ + struct device_node *root; + + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) + return -EOPNOTSUPP; + + root = of_find_node_by_path("/"); + if (!root) + return -EINVAL; + + *addr_cells = of_n_addr_cells(root); + *size_cells = of_n_size_cells(root); + + of_node_put(root); + + return 0; +} + +/** + * get_ima_kexec_buffer - Get address and size of IMA kexec buffer + * + * @fdt: Flattened Device Tree + * @chosen_node: Offset of chosen node in the FDT + * @addr: Return address of the node + * @size: Return size of the node + * + * Return: 0 on success, or negative errno on error. + */ +int get_ima_kexec_buffer(void *fdt, int chosen_node, + unsigned long *addr, size_t *size) +{ + const void *prop; + int addr_cells, size_cells, prop_len; + int rc; + + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) + return -EOPNOTSUPP; + + rc = get_root_addr_size_cells(&addr_cells, &size_cells); + if (rc) + return rc; + + if (fdt) + prop = fdt_getprop(fdt, chosen_node, + "linux,ima-kexec-buffer", &prop_len); + else + prop = of_get_property(of_chosen, + "linux,ima-kexec-buffer", &prop_len); + + if (!prop) + return -ENOENT; + + if (prop_len < 4 * (addr_cells + size_cells)) + return -EINVAL; + + *addr = of_read_number(prop, addr_cells); + *size = of_read_number(prop + 4 * addr_cells, size_cells); + + return 0; +} diff --git a/include/linux/kexec.h b/include/linux/kexec.h index d0234c4815da..10ff704ab670 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -408,6 +408,9 @@ static inline int kexec_crash_loaded(void) { return 0; } #endif /* CONFIG_KEXEC_CORE */ #if defined(CONFIG_OF_FLATTREE) +extern int get_root_addr_size_cells(int *addr_cells, int *size_cells); +extern int get_ima_kexec_buffer(void *fdt, int chosen_node, + unsigned long *addr, size_t *size); extern int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size); #endif /* CONFIG_OF_FLATTREE */