From: David Gibson <david@gibson.dropbear.id.au> To: u-boot@lists.denx.de Subject: [U-Boot] [PATCH v3 10/12] libfdt: Add overlay application function Date: Mon, 27 Jun 2016 15:26:07 +1000 [thread overview] Message-ID: <20160627052607.GK4242@voom.fritz.box> (raw) In-Reply-To: <20160624142757.32735-11-maxime.ripard@free-electrons.com> On Fri, Jun 24, 2016 at 04:27:55PM +0200, Maxime Ripard wrote: > The device tree overlays are a good way to deal with user-modifyable > boards or boards with some kind of an expansion mechanism where we can > easily plug new board in (like the BBB, the Raspberry Pi or the CHIP). > > Add a new function to merge overlays with a base device tree. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > --- > include/libfdt.h | 30 ++++ > lib/Kconfig | 5 + > lib/libfdt/Makefile | 2 + > lib/libfdt/fdt_overlay.c | 381 +++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 418 insertions(+) > create mode 100644 lib/libfdt/fdt_overlay.c > > diff --git a/include/libfdt.h b/include/libfdt.h > index b8758de3ae54..039ecb0c1ba7 100644 > --- a/include/libfdt.h > +++ b/include/libfdt.h > @@ -1747,6 +1747,36 @@ int fdt_add_subnode(void *fdt, int parentoffset, const char *name); > */ > int fdt_del_node(void *fdt, int nodeoffset); > > +/** > + * fdt_overlay_apply - Applies a DT overlay on a base DT > + * @fdt: pointer to the base device tree blob > + * @fdto: pointer to the device tree overlay blob > + * > + * fdt_overlay_apply() will apply the given device tree overlay on the > + * given base device tree. > + * > + * Expect the base device tree to be modified, even if the function > + * returns an error. > + * > + * returns: > + * 0, on success > + * -FDT_ERR_NOSPACE, there's not enough space in the base device tree > + * -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or > + * properties in the base DT > + * -FDT_ERR_BADPHANDLE, the phandles in the overlay do not have the right > + * magic > + * -FDT_ERR_INTERNAL, > + * -FDT_ERR_BADLAYOUT, > + * -FDT_ERR_BADMAGIC, > + * -FDT_ERR_BADOFFSET, > + * -FDT_ERR_BADPATH, > + * -FDT_ERR_BADVERSION, > + * -FDT_ERR_BADSTRUCTURE, > + * -FDT_ERR_BADSTATE, > + * -FDT_ERR_TRUNCATED, standard meanings > + */ > +int fdt_overlay_apply(void *fdt, void *fdto); > + > /**********************************************************************/ > /* Debugging / informational functions */ > /**********************************************************************/ > diff --git a/lib/Kconfig b/lib/Kconfig > index 02ca4058d37e..16ff01a2cd37 100644 > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -139,6 +139,11 @@ config OF_LIBFDT > particular compatible nodes. The library operates on a flattened > version of the device tree. > > +config OF_LIBFDT_OVERLAY > + bool "Enable the FDT library overlay support" > + help > + This enables the FDT library (libfdt) overlay support. > + > config SPL_OF_LIBFDT > bool "Enable the FDT library for SPL" > default y if SPL_OF_CONTROL > diff --git a/lib/libfdt/Makefile b/lib/libfdt/Makefile > index 8b86c15904cb..6ef8290f4e09 100644 > --- a/lib/libfdt/Makefile > +++ b/lib/libfdt/Makefile > @@ -15,3 +15,5 @@ obj-y += \ > fdt_empty_tree.o \ > fdt_addresses.o \ > fdt_region.o > + > +obj-$(CONFIG_OF_LIBFDT_OVERLAY) += fdt_overlay.o > diff --git a/lib/libfdt/fdt_overlay.c b/lib/libfdt/fdt_overlay.c > new file mode 100644 > index 000000000000..5835a90afafe > --- /dev/null > +++ b/lib/libfdt/fdt_overlay.c > @@ -0,0 +1,381 @@ > +#include "libfdt_env.h" > + > +#include <fdt.h> > +#include <libfdt.h> > + > +#include "libfdt_internal.h" > + > +static uint32_t overlay_get_target_phandle(const void *fdto, int fragment) > +{ > + const uint32_t *val; > + int len; > + > + val = fdt_getprop(fdto, fragment, "target", &len); > + if (!val || (*val == 0xffffffff) || (len != sizeof(*val))) > + return 0; This doesn't distinguish between a missing property (which may indicate a valid overlay using a target-path or some other method) and a badly formatted 'target' property, which is definitely an error in the overlay. I think those should be treated differently. > + return fdt32_to_cpu(*val); > +} > + > +static int overlay_get_target(const void *fdt, const void *fdto, > + int fragment) > +{ > + uint32_t phandle; > + const char *path; > + > + /* Try first to do a phandle based lookup */ > + phandle = overlay_get_target_phandle(fdto, fragment); > + if (phandle) > + return fdt_node_offset_by_phandle(fdt, phandle); > + > + /* And then a path based lookup */ > + path = fdt_getprop(fdto, fragment, "target-path", NULL); > + if (!path) > + return -FDT_ERR_NOTFOUND; > + > + return fdt_path_offset(fdt, path); > +} > + > +static int overlay_phandle_add_offset(void *fdt, int node, > + const char *name, uint32_t delta) > +{ > + const uint32_t *val; > + uint32_t adj_val; > + int len; > + > + val = fdt_getprop(fdt, node, name, &len); > + if (!val) > + return len; > + > + if (len != sizeof(*val)) > + return -FDT_ERR_BADSTRUCTURE; > + > + adj_val = fdt32_to_cpu(*val); > + adj_val += delta; You should probably check for overflow here. > + > + return fdt_setprop_inplace_u32(fdt, node, name, adj_val); > +} > + > +static int overlay_adjust_node_phandles(void *fdto, int node, > + uint32_t delta) > +{ > + bool found = false; > + int child; > + int ret; > + > + ret = overlay_phandle_add_offset(fdto, node, "phandle", delta); > + if (ret && ret != -FDT_ERR_NOTFOUND) > + return ret; > + > + if (!ret) > + found = true; > + > + ret = overlay_phandle_add_offset(fdto, node, "linux,phandle", delta); > + if (ret && ret != -FDT_ERR_NOTFOUND) > + return ret; I think the check for phandle vs. linux,phandle should be folded into overlay_phandle_add_offset(). > + /* > + * If neither phandle nor linux,phandle have been found return > + * an error. > + */ > + if (!found && !ret) > + return ret; > + > + fdt_for_each_subnode(fdto, child, node) > + overlay_adjust_node_phandles(fdto, child, delta); > + > + return 0; > +} > + > +static int overlay_adjust_local_phandles(void *fdto, uint32_t delta) > +{ > + /* > + * Start adjusting the phandles from the overlay root > + */ > + return overlay_adjust_node_phandles(fdto, 0, delta); > +} > + > +static int overlay_update_local_node_references(void *fdto, > + int tree_node, > + int fixup_node, > + uint32_t delta) > +{ > + int fixup_prop; > + int fixup_child; > + int ret; > + > + fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) { > + const uint32_t *val = NULL; > + uint32_t adj_val, index; > + const char *name; > + int fixup_len; > + int tree_len; > + > + val = fdt_getprop_by_offset(fdto, fixup_prop, > + &name, &fixup_len); > + if (!val) > + return fixup_len; > + index = fdt32_to_cpu(*val); This still doesn't handle the case of multiple fixups within the same property. That would be entirely plausible for something like an interrupt-map property. > + val = fdt_getprop(fdto, tree_node, name, &tree_len); > + if (!val) > + return tree_len; > + > + adj_val = fdt32_to_cpu(*(val + (index / sizeof(uint32_t)))); phandle values need not be aligned within the property containint them (e.g. properties which mix strings and integer values). So you're going to need to work directly with a byte offset here. > + adj_val += delta; > + adj_val = cpu_to_fdt32(adj_val); > + > + ret = fdt_setprop_inplace_namelen_by_index(fdto, tree_node, > + name, strlen(name), > + index, &adj_val, > + sizeof(adj_val)); > + if (ret) > + return ret; > + } > + > + fdt_for_each_subnode(fdto, fixup_child, fixup_node) { > + const char *fixup_child_name = fdt_get_name(fdto, fixup_child, > + NULL); > + int tree_child; > + > + tree_child = fdt_subnode_offset(fdto, tree_node, > + fixup_child_name); > + if (tree_child < 0) > + return tree_child; > + > + ret = overlay_update_local_node_references(fdto, > + tree_child, > + fixup_child, > + delta); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +static int overlay_update_local_references(void *dto, uint32_t delta) > +{ > + int fixups; > + > + fixups = fdt_path_offset(dto, "/__local_fixups__"); > + if (fixups < 0) { > + /* > + * There's no local phandles to adjust, bail out > + */ > + if (fixups == -FDT_ERR_NOTFOUND) > + return 0; > + > + return fixups; > + } > + > + /* > + * Update our local references from the root of the tree > + */ > + return overlay_update_local_node_references(dto, 0, fixups, > + delta); > +} > + > +static int overlay_fixup_one_phandle(void *fdt, void *fdto, > + int symbols_off, > + const char *path, uint32_t path_len, > + const char *name, uint32_t name_len, > + int index, const char *label) > +{ > + const char *symbol_path; > + uint32_t phandle; > + int symbol_off, fixup_off; > + int prop_len; > + > + symbol_path = fdt_getprop(fdt, symbols_off, label, > + &prop_len); > + if (!symbol_path) > + return -FDT_ERR_NOTFOUND; > + > + symbol_off = fdt_path_offset(fdt, symbol_path); > + if (symbol_off < 0) > + return symbol_off; > + > + phandle = fdt_get_phandle(fdt, symbol_off); > + if (!phandle) > + return -FDT_ERR_NOTFOUND; > + > + fixup_off = fdt_path_offset_namelen(fdto, path, path_len); > + if (fixup_off < 0) > + return fixup_off; > + > + phandle = cpu_to_fdt32(phandle); > + return fdt_setprop_inplace_namelen_by_index(fdto, fixup_off, > + name, name_len, index, > + &phandle, sizeof(phandle)); This will be broken on BE systems because fdt_get_phandle() byteswaps to native order, but setprop_inplace doesn't byteswap back (because it's input is a byte array, not a u32). > +}; > + > +static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off, > + int property) > +{ > + const char *value; > + const char *label; > + int len; > + > + value = fdt_getprop_by_offset(fdto, property, > + &label, &len); > + if (!value) > + return len; > + > + do { > + const char *prop_string = value; > + const char *path, *name; > + uint32_t path_len, name_len; > + char *sep, *endptr; > + int index; > + int ret; > + > + path = prop_string; > + sep = strchr(prop_string, ':'); > + path_len = sep - path; You need to check for strchr() returning NULL (indicating a badly formatted fixup missing a separator). Also... strchr() is not safe. Again, if the fixup string is badly formatted and doesn't have a terminating \0, this could overrun, so you want memchr() instead. > + name = sep + 1; > + sep = strchr(name, ':'); > + name_len = sep - name; And again. > + index = strtoul(sep + 1, &endptr, 10); > + if (endptr <= (sep + 1)) > + return -FDT_ERR_BADSTRUCTURE; IIRC the index value is supposed to go to the end of that portion of the fixup, so you should be able to check for *endptr == '\0'. Except.. strtoul() could also overrun if the fixup property doesn't contain a \0 like it should. So I think you'd be better off using a memchr() (or strnlen()) to search for the \0 before you attempt parsing the innards of a single fixup string. Ugh. I hate that we're parsing text numbers in decimal here, but we're pretty much stuck with that format here. Doubly so that it's a gratuitously different way of encoding the (node, property, offset) tuple from local_fixups. > + index = strtoul(sep + 1, &endptr, 10); > + if (endptr <= (sep + 1)) > + return -FDT_ERR_BADSTRUCTURE; > + > + len -= strlen(prop_string) + 1; > + value += strlen(prop_string) + 1; Please don't double call strlen() on the same string - remember it's O(n) in C. > + > + ret = overlay_fixup_one_phandle(fdt, fdto, symbols_off, > + path, path_len, name, name_len, > + index, label); > + if (ret) > + return ret; > + } while (len > 0); > + > + return 0; > +} > + > +static int overlay_fixup_phandles(void *dt, void *dto) > +{ > + int fixups_off, symbols_off; > + int property; > + > + symbols_off = fdt_path_offset(dt, "/__symbols__"); > + fixups_off = fdt_path_offset(dto, "/__fixups__"); > + > + fdt_for_each_property_offset(property, dto, fixups_off) > + overlay_fixup_phandle(dt, dto, symbols_off, property); > + > + return 0; > +} > + > +static int apply_overlay_node(void *dt, int target, > + void *dto, int overlay) I think 'overlay' should be 'fragment' here for consistency? > +{ > + int property; > + int node; > + > + fdt_for_each_property_offset(property, dto, overlay) { > + const char *name; > + const void *prop; > + int prop_len; > + int ret; > + > + prop = fdt_getprop_by_offset(dto, property, &name, > + &prop_len); > + if (!prop) > + return -FDT_ERR_INTERNAL; Actually, you probably should check the error code returned in prop_len. Getting a NOTFOUND would indicate an internal error, but you could also get BADSTRUCTURE or similar errors which would indicate an error in input. > + > + ret = fdt_setprop(dt, target, name, prop, prop_len); > + if (ret) > + return ret; > + } > + > + fdt_for_each_subnode(dto, node, overlay) { > + const char *name = fdt_get_name(dto, node, NULL); > + int nnode; > + int ret; > + > + nnode = fdt_add_subnode(dt, target, name); > + if (nnode == -FDT_ERR_EXISTS) > + nnode = fdt_subnode_offset(dt, target, name); > + > + if (nnode < 0) > + return nnode; > + > + ret = apply_overlay_node(dt, nnode, dto, node); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +static int overlay_merge(void *dt, void *dto) > +{ > + int fragment; > + > + fdt_for_each_subnode(dto, fragment, 0) { > + int overlay; > + int target; > + int ret; > + > + target = overlay_get_target(dt, dto, fragment); > + if (target < 0) > + continue; > + > + overlay = fdt_subnode_offset(dto, fragment, "__overlay__"); > + if (overlay < 0) > + return overlay; > + > + ret = apply_overlay_node(dt, target, dto, overlay); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +int fdt_overlay_apply(void *fdt, void *fdto) > +{ > + uint32_t delta = fdt_get_max_phandle(fdt) + 1; > + int ret; > + > + FDT_CHECK_HEADER(fdt); > + FDT_CHECK_HEADER(fdto); > + > + ret = overlay_adjust_local_phandles(fdto, delta); > + if (ret) > + goto err; > + > + ret = overlay_update_local_references(fdto, delta); > + if (ret) > + goto err; > + > + ret = overlay_fixup_phandles(fdt, fdto); > + if (ret) > + goto err; > + > + ret = overlay_merge(fdt, fdto); > + if (!ret) > + goto out; > + > +err: This is a confusing use of gotos - this looks like it is in the exit path for both success and failure cases, but it's not due to the easy-to-miss goto out above. > + /* > + * The base device tree might have been damaged, erase its > + * magic. > + */ > + fdt_set_magic(fdt, ~0); > + > +out: > + /* > + * The overlay has been damaged, erase its magic. > + */ > + fdt_set_magic(fdto, ~0); > + > + return ret; > +} -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. 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From: David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org> To: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> Cc: "Pantelis Antoniou" <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>, "Simon Glass" <sjg-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>, "Boris Brezillon" <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>, "Alexander Kaplan" <alex-MflLfwwFzuz+yO7R74ARew@public.gmane.org>, "Thomas Petazzoni" <thomas.petazzoni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>, devicetree-compiler-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Antoine Ténart" <antoine.tenart-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>, "Hans de Goede" <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, "Tom Rini" <trini-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>, u-boot-0aAXYlwwYIKGBzrmiIFOJg@public.gmane.org, "Stefan Agner" <stefan-XLVq0VzYD2Y@public.gmane.org> Subject: Re: [PATCH v3 10/12] libfdt: Add overlay application function Date: Mon, 27 Jun 2016 15:26:07 +1000 [thread overview] Message-ID: <20160627052607.GK4242@voom.fritz.box> (raw) In-Reply-To: <20160624142757.32735-11-maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> [-- Attachment #1: Type: text/plain, Size: 15408 bytes --] On Fri, Jun 24, 2016 at 04:27:55PM +0200, Maxime Ripard wrote: > The device tree overlays are a good way to deal with user-modifyable > boards or boards with some kind of an expansion mechanism where we can > easily plug new board in (like the BBB, the Raspberry Pi or the CHIP). > > Add a new function to merge overlays with a base device tree. > > Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> > --- > include/libfdt.h | 30 ++++ > lib/Kconfig | 5 + > lib/libfdt/Makefile | 2 + > lib/libfdt/fdt_overlay.c | 381 +++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 418 insertions(+) > create mode 100644 lib/libfdt/fdt_overlay.c > > diff --git a/include/libfdt.h b/include/libfdt.h > index b8758de3ae54..039ecb0c1ba7 100644 > --- a/include/libfdt.h > +++ b/include/libfdt.h > @@ -1747,6 +1747,36 @@ int fdt_add_subnode(void *fdt, int parentoffset, const char *name); > */ > int fdt_del_node(void *fdt, int nodeoffset); > > +/** > + * fdt_overlay_apply - Applies a DT overlay on a base DT > + * @fdt: pointer to the base device tree blob > + * @fdto: pointer to the device tree overlay blob > + * > + * fdt_overlay_apply() will apply the given device tree overlay on the > + * given base device tree. > + * > + * Expect the base device tree to be modified, even if the function > + * returns an error. > + * > + * returns: > + * 0, on success > + * -FDT_ERR_NOSPACE, there's not enough space in the base device tree > + * -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or > + * properties in the base DT > + * -FDT_ERR_BADPHANDLE, the phandles in the overlay do not have the right > + * magic > + * -FDT_ERR_INTERNAL, > + * -FDT_ERR_BADLAYOUT, > + * -FDT_ERR_BADMAGIC, > + * -FDT_ERR_BADOFFSET, > + * -FDT_ERR_BADPATH, > + * -FDT_ERR_BADVERSION, > + * -FDT_ERR_BADSTRUCTURE, > + * -FDT_ERR_BADSTATE, > + * -FDT_ERR_TRUNCATED, standard meanings > + */ > +int fdt_overlay_apply(void *fdt, void *fdto); > + > /**********************************************************************/ > /* Debugging / informational functions */ > /**********************************************************************/ > diff --git a/lib/Kconfig b/lib/Kconfig > index 02ca4058d37e..16ff01a2cd37 100644 > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -139,6 +139,11 @@ config OF_LIBFDT > particular compatible nodes. The library operates on a flattened > version of the device tree. > > +config OF_LIBFDT_OVERLAY > + bool "Enable the FDT library overlay support" > + help > + This enables the FDT library (libfdt) overlay support. > + > config SPL_OF_LIBFDT > bool "Enable the FDT library for SPL" > default y if SPL_OF_CONTROL > diff --git a/lib/libfdt/Makefile b/lib/libfdt/Makefile > index 8b86c15904cb..6ef8290f4e09 100644 > --- a/lib/libfdt/Makefile > +++ b/lib/libfdt/Makefile > @@ -15,3 +15,5 @@ obj-y += \ > fdt_empty_tree.o \ > fdt_addresses.o \ > fdt_region.o > + > +obj-$(CONFIG_OF_LIBFDT_OVERLAY) += fdt_overlay.o > diff --git a/lib/libfdt/fdt_overlay.c b/lib/libfdt/fdt_overlay.c > new file mode 100644 > index 000000000000..5835a90afafe > --- /dev/null > +++ b/lib/libfdt/fdt_overlay.c > @@ -0,0 +1,381 @@ > +#include "libfdt_env.h" > + > +#include <fdt.h> > +#include <libfdt.h> > + > +#include "libfdt_internal.h" > + > +static uint32_t overlay_get_target_phandle(const void *fdto, int fragment) > +{ > + const uint32_t *val; > + int len; > + > + val = fdt_getprop(fdto, fragment, "target", &len); > + if (!val || (*val == 0xffffffff) || (len != sizeof(*val))) > + return 0; This doesn't distinguish between a missing property (which may indicate a valid overlay using a target-path or some other method) and a badly formatted 'target' property, which is definitely an error in the overlay. I think those should be treated differently. > + return fdt32_to_cpu(*val); > +} > + > +static int overlay_get_target(const void *fdt, const void *fdto, > + int fragment) > +{ > + uint32_t phandle; > + const char *path; > + > + /* Try first to do a phandle based lookup */ > + phandle = overlay_get_target_phandle(fdto, fragment); > + if (phandle) > + return fdt_node_offset_by_phandle(fdt, phandle); > + > + /* And then a path based lookup */ > + path = fdt_getprop(fdto, fragment, "target-path", NULL); > + if (!path) > + return -FDT_ERR_NOTFOUND; > + > + return fdt_path_offset(fdt, path); > +} > + > +static int overlay_phandle_add_offset(void *fdt, int node, > + const char *name, uint32_t delta) > +{ > + const uint32_t *val; > + uint32_t adj_val; > + int len; > + > + val = fdt_getprop(fdt, node, name, &len); > + if (!val) > + return len; > + > + if (len != sizeof(*val)) > + return -FDT_ERR_BADSTRUCTURE; > + > + adj_val = fdt32_to_cpu(*val); > + adj_val += delta; You should probably check for overflow here. > + > + return fdt_setprop_inplace_u32(fdt, node, name, adj_val); > +} > + > +static int overlay_adjust_node_phandles(void *fdto, int node, > + uint32_t delta) > +{ > + bool found = false; > + int child; > + int ret; > + > + ret = overlay_phandle_add_offset(fdto, node, "phandle", delta); > + if (ret && ret != -FDT_ERR_NOTFOUND) > + return ret; > + > + if (!ret) > + found = true; > + > + ret = overlay_phandle_add_offset(fdto, node, "linux,phandle", delta); > + if (ret && ret != -FDT_ERR_NOTFOUND) > + return ret; I think the check for phandle vs. linux,phandle should be folded into overlay_phandle_add_offset(). > + /* > + * If neither phandle nor linux,phandle have been found return > + * an error. > + */ > + if (!found && !ret) > + return ret; > + > + fdt_for_each_subnode(fdto, child, node) > + overlay_adjust_node_phandles(fdto, child, delta); > + > + return 0; > +} > + > +static int overlay_adjust_local_phandles(void *fdto, uint32_t delta) > +{ > + /* > + * Start adjusting the phandles from the overlay root > + */ > + return overlay_adjust_node_phandles(fdto, 0, delta); > +} > + > +static int overlay_update_local_node_references(void *fdto, > + int tree_node, > + int fixup_node, > + uint32_t delta) > +{ > + int fixup_prop; > + int fixup_child; > + int ret; > + > + fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) { > + const uint32_t *val = NULL; > + uint32_t adj_val, index; > + const char *name; > + int fixup_len; > + int tree_len; > + > + val = fdt_getprop_by_offset(fdto, fixup_prop, > + &name, &fixup_len); > + if (!val) > + return fixup_len; > + index = fdt32_to_cpu(*val); This still doesn't handle the case of multiple fixups within the same property. That would be entirely plausible for something like an interrupt-map property. > + val = fdt_getprop(fdto, tree_node, name, &tree_len); > + if (!val) > + return tree_len; > + > + adj_val = fdt32_to_cpu(*(val + (index / sizeof(uint32_t)))); phandle values need not be aligned within the property containint them (e.g. properties which mix strings and integer values). So you're going to need to work directly with a byte offset here. > + adj_val += delta; > + adj_val = cpu_to_fdt32(adj_val); > + > + ret = fdt_setprop_inplace_namelen_by_index(fdto, tree_node, > + name, strlen(name), > + index, &adj_val, > + sizeof(adj_val)); > + if (ret) > + return ret; > + } > + > + fdt_for_each_subnode(fdto, fixup_child, fixup_node) { > + const char *fixup_child_name = fdt_get_name(fdto, fixup_child, > + NULL); > + int tree_child; > + > + tree_child = fdt_subnode_offset(fdto, tree_node, > + fixup_child_name); > + if (tree_child < 0) > + return tree_child; > + > + ret = overlay_update_local_node_references(fdto, > + tree_child, > + fixup_child, > + delta); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +static int overlay_update_local_references(void *dto, uint32_t delta) > +{ > + int fixups; > + > + fixups = fdt_path_offset(dto, "/__local_fixups__"); > + if (fixups < 0) { > + /* > + * There's no local phandles to adjust, bail out > + */ > + if (fixups == -FDT_ERR_NOTFOUND) > + return 0; > + > + return fixups; > + } > + > + /* > + * Update our local references from the root of the tree > + */ > + return overlay_update_local_node_references(dto, 0, fixups, > + delta); > +} > + > +static int overlay_fixup_one_phandle(void *fdt, void *fdto, > + int symbols_off, > + const char *path, uint32_t path_len, > + const char *name, uint32_t name_len, > + int index, const char *label) > +{ > + const char *symbol_path; > + uint32_t phandle; > + int symbol_off, fixup_off; > + int prop_len; > + > + symbol_path = fdt_getprop(fdt, symbols_off, label, > + &prop_len); > + if (!symbol_path) > + return -FDT_ERR_NOTFOUND; > + > + symbol_off = fdt_path_offset(fdt, symbol_path); > + if (symbol_off < 0) > + return symbol_off; > + > + phandle = fdt_get_phandle(fdt, symbol_off); > + if (!phandle) > + return -FDT_ERR_NOTFOUND; > + > + fixup_off = fdt_path_offset_namelen(fdto, path, path_len); > + if (fixup_off < 0) > + return fixup_off; > + > + phandle = cpu_to_fdt32(phandle); > + return fdt_setprop_inplace_namelen_by_index(fdto, fixup_off, > + name, name_len, index, > + &phandle, sizeof(phandle)); This will be broken on BE systems because fdt_get_phandle() byteswaps to native order, but setprop_inplace doesn't byteswap back (because it's input is a byte array, not a u32). > +}; > + > +static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off, > + int property) > +{ > + const char *value; > + const char *label; > + int len; > + > + value = fdt_getprop_by_offset(fdto, property, > + &label, &len); > + if (!value) > + return len; > + > + do { > + const char *prop_string = value; > + const char *path, *name; > + uint32_t path_len, name_len; > + char *sep, *endptr; > + int index; > + int ret; > + > + path = prop_string; > + sep = strchr(prop_string, ':'); > + path_len = sep - path; You need to check for strchr() returning NULL (indicating a badly formatted fixup missing a separator). Also... strchr() is not safe. Again, if the fixup string is badly formatted and doesn't have a terminating \0, this could overrun, so you want memchr() instead. > + name = sep + 1; > + sep = strchr(name, ':'); > + name_len = sep - name; And again. > + index = strtoul(sep + 1, &endptr, 10); > + if (endptr <= (sep + 1)) > + return -FDT_ERR_BADSTRUCTURE; IIRC the index value is supposed to go to the end of that portion of the fixup, so you should be able to check for *endptr == '\0'. Except.. strtoul() could also overrun if the fixup property doesn't contain a \0 like it should. So I think you'd be better off using a memchr() (or strnlen()) to search for the \0 before you attempt parsing the innards of a single fixup string. Ugh. I hate that we're parsing text numbers in decimal here, but we're pretty much stuck with that format here. Doubly so that it's a gratuitously different way of encoding the (node, property, offset) tuple from local_fixups. > + index = strtoul(sep + 1, &endptr, 10); > + if (endptr <= (sep + 1)) > + return -FDT_ERR_BADSTRUCTURE; > + > + len -= strlen(prop_string) + 1; > + value += strlen(prop_string) + 1; Please don't double call strlen() on the same string - remember it's O(n) in C. > + > + ret = overlay_fixup_one_phandle(fdt, fdto, symbols_off, > + path, path_len, name, name_len, > + index, label); > + if (ret) > + return ret; > + } while (len > 0); > + > + return 0; > +} > + > +static int overlay_fixup_phandles(void *dt, void *dto) > +{ > + int fixups_off, symbols_off; > + int property; > + > + symbols_off = fdt_path_offset(dt, "/__symbols__"); > + fixups_off = fdt_path_offset(dto, "/__fixups__"); > + > + fdt_for_each_property_offset(property, dto, fixups_off) > + overlay_fixup_phandle(dt, dto, symbols_off, property); > + > + return 0; > +} > + > +static int apply_overlay_node(void *dt, int target, > + void *dto, int overlay) I think 'overlay' should be 'fragment' here for consistency? > +{ > + int property; > + int node; > + > + fdt_for_each_property_offset(property, dto, overlay) { > + const char *name; > + const void *prop; > + int prop_len; > + int ret; > + > + prop = fdt_getprop_by_offset(dto, property, &name, > + &prop_len); > + if (!prop) > + return -FDT_ERR_INTERNAL; Actually, you probably should check the error code returned in prop_len. Getting a NOTFOUND would indicate an internal error, but you could also get BADSTRUCTURE or similar errors which would indicate an error in input. > + > + ret = fdt_setprop(dt, target, name, prop, prop_len); > + if (ret) > + return ret; > + } > + > + fdt_for_each_subnode(dto, node, overlay) { > + const char *name = fdt_get_name(dto, node, NULL); > + int nnode; > + int ret; > + > + nnode = fdt_add_subnode(dt, target, name); > + if (nnode == -FDT_ERR_EXISTS) > + nnode = fdt_subnode_offset(dt, target, name); > + > + if (nnode < 0) > + return nnode; > + > + ret = apply_overlay_node(dt, nnode, dto, node); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +static int overlay_merge(void *dt, void *dto) > +{ > + int fragment; > + > + fdt_for_each_subnode(dto, fragment, 0) { > + int overlay; > + int target; > + int ret; > + > + target = overlay_get_target(dt, dto, fragment); > + if (target < 0) > + continue; > + > + overlay = fdt_subnode_offset(dto, fragment, "__overlay__"); > + if (overlay < 0) > + return overlay; > + > + ret = apply_overlay_node(dt, target, dto, overlay); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +int fdt_overlay_apply(void *fdt, void *fdto) > +{ > + uint32_t delta = fdt_get_max_phandle(fdt) + 1; > + int ret; > + > + FDT_CHECK_HEADER(fdt); > + FDT_CHECK_HEADER(fdto); > + > + ret = overlay_adjust_local_phandles(fdto, delta); > + if (ret) > + goto err; > + > + ret = overlay_update_local_references(fdto, delta); > + if (ret) > + goto err; > + > + ret = overlay_fixup_phandles(fdt, fdto); > + if (ret) > + goto err; > + > + ret = overlay_merge(fdt, fdto); > + if (!ret) > + goto out; > + > +err: This is a confusing use of gotos - this looks like it is in the exit path for both success and failure cases, but it's not due to the easy-to-miss goto out above. > + /* > + * The base device tree might have been damaged, erase its > + * magic. > + */ > + fdt_set_magic(fdt, ~0); > + > +out: > + /* > + * The overlay has been damaged, erase its magic. > + */ > + fdt_set_magic(fdto, ~0); > + > + return ret; > +} -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 819 bytes --]
next prev parent reply other threads:[~2016-06-27 5:26 UTC|newest] Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-24 14:27 [U-Boot] [PATCH v3 00/12] cmd: fdt: Add device tree overlays support Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-24 14:27 ` [U-Boot] [PATCH v3 01/12] cmd: fdt: Narrow the check for fdt addr Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-24 14:27 ` [U-Boot] [PATCH v3 02/12] scripts: Makefile.lib: Sanitize DTB names Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-24 14:27 ` [U-Boot] [PATCH v3 03/12] vsprintf: Include stdarg for va_list Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-24 14:27 ` [U-Boot] [PATCH v3 04/12] libfdt: Add new headers and defines Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-26 2:53 ` [U-Boot] " Simon Glass 2016-06-26 2:53 ` Simon Glass 2016-06-26 15:39 ` [U-Boot] " David Gibson 2016-06-26 15:39 ` David Gibson 2016-06-27 7:25 ` [U-Boot] " Maxime Ripard 2016-06-27 7:25 ` Maxime Ripard 2016-06-28 3:02 ` [U-Boot] " David Gibson 2016-06-28 3:02 ` David Gibson 2016-06-24 14:27 ` [U-Boot] [PATCH v3 05/12] libfdt: Add iterator over properties Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-26 2:53 ` [U-Boot] " Simon Glass 2016-06-26 2:53 ` Simon Glass 2016-06-24 14:27 ` [U-Boot] [PATCH v3 06/12] libfdt: Add max phandle retrieval function Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-26 2:53 ` [U-Boot] " Simon Glass 2016-06-26 2:53 ` Simon Glass 2016-06-24 14:27 ` [U-Boot] [PATCH v3 07/12] libfdt: Add fdt_setprop_inplace_by_index Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-26 2:53 ` [U-Boot] " Simon Glass 2016-06-26 2:53 ` Simon Glass 2016-06-26 8:09 ` [U-Boot] " Maxime Ripard 2016-06-26 8:09 ` Maxime Ripard 2016-06-26 15:45 ` [U-Boot] " David Gibson 2016-06-26 15:45 ` David Gibson 2016-06-27 9:16 ` [U-Boot] " Maxime Ripard 2016-06-27 9:16 ` Maxime Ripard 2016-06-28 3:05 ` [U-Boot] " David Gibson 2016-06-28 3:05 ` David Gibson 2016-06-24 14:27 ` [U-Boot] [PATCH v3 08/12] libfdt: Add fdt_path_offset_namelen Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-26 2:53 ` [U-Boot] " Simon Glass 2016-06-26 2:53 ` Simon Glass 2016-06-26 8:10 ` [U-Boot] " Maxime Ripard 2016-06-26 8:10 ` Maxime Ripard 2016-06-29 3:27 ` [U-Boot] " Simon Glass 2016-06-29 3:27 ` Simon Glass 2016-06-26 15:47 ` [U-Boot] " David Gibson 2016-06-26 15:47 ` David Gibson 2016-06-24 14:27 ` [U-Boot] [PATCH v3 09/12] libfdt: Add fdt_getprop_namelen_w Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-26 2:53 ` [U-Boot] " Simon Glass 2016-06-26 2:53 ` Simon Glass 2016-06-26 8:11 ` [U-Boot] " Maxime Ripard 2016-06-26 8:11 ` Maxime Ripard 2016-06-26 15:49 ` [U-Boot] " David Gibson 2016-06-26 15:49 ` David Gibson 2016-06-27 7:29 ` [U-Boot] " Maxime Ripard 2016-06-27 7:29 ` Maxime Ripard 2016-06-24 14:27 ` [U-Boot] [PATCH v3 10/12] libfdt: Add overlay application function Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-26 2:53 ` [U-Boot] " Simon Glass 2016-06-26 2:53 ` Simon Glass 2016-06-27 7:13 ` [U-Boot] " Maxime Ripard 2016-06-27 7:13 ` Maxime Ripard 2016-06-27 5:26 ` David Gibson [this message] 2016-06-27 5:26 ` David Gibson 2016-06-27 11:40 ` [U-Boot] " Maxime Ripard 2016-06-27 11:40 ` Maxime Ripard 2016-06-28 3:12 ` [U-Boot] " David Gibson 2016-06-28 3:12 ` David Gibson 2016-06-30 2:34 ` [U-Boot] " Frank Rowand 2016-06-30 2:34 ` Frank Rowand 2016-06-30 5:08 ` [U-Boot] " David Gibson 2016-06-30 5:08 ` David Gibson 2016-06-24 14:27 ` [U-Boot] [PATCH v3 11/12] cmd: fdt: add fdt overlay application subcommand Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-24 14:27 ` [U-Boot] [PATCH v3 12/12] tests: Introduce DT overlay tests Maxime Ripard 2016-06-24 14:27 ` Maxime Ripard 2016-06-27 5:26 ` [U-Boot] " David Gibson 2016-06-27 5:26 ` David Gibson 2016-06-27 6:30 ` [U-Boot] " Maxime Ripard 2016-06-27 6:30 ` Maxime Ripard 2016-06-27 6:47 ` [U-Boot] " David Gibson 2016-06-27 6:47 ` David Gibson 2016-06-26 15:37 ` [U-Boot] [PATCH v3 00/12] cmd: fdt: Add device tree overlays support David Gibson 2016-06-26 15:37 ` David Gibson 2016-06-27 6:29 ` [U-Boot] " Maxime Ripard 2016-06-27 6:29 ` Maxime Ripard 2016-06-29 3:28 ` [U-Boot] " Simon Glass 2016-06-29 3:28 ` Simon Glass
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