From mboxrd@z Thu Jan 1 00:00:00 1970 From: Romain Naour Date: Sat, 12 Jun 2021 11:40:10 +0200 Subject: [Buildroot] [PATCH 1/6] board/qemu/sparc64-sun4u: avoid gcc-11 warning to build the kernel Message-ID: <20210612094015.6792-1-romain.naour@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net gcc-11 warns about what appears to be an out-of-range array access but stop the build due to -Werror added to cflags: arch/sparc/kernel/mdesc.c: In function 'mdesc_node_by_name': arch/sparc/kernel/mdesc.c:647:22: error: 'strcmp' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread] 647 | if (!strcmp(names + ep[ret].name_offset, name)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/sparc/kernel/mdesc.c:77:33: note: at offset 16 into source object 'mdesc' of size 16 77 | struct mdesc_hdr mdesc; | ^~~~~ arch/sparc/kernel/mdesc.c: In function 'mdesc_get_property': arch/sparc/kernel/mdesc.c:692:22: error: 'strcmp' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread] 692 | if (!strcmp(names + ep->name_offset, name)) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/sparc/kernel/mdesc.c:77:33: note: at offset 16 into source object 'mdesc' of size 16 77 | struct mdesc_hdr mdesc; | ^~~~~ arch/sparc/kernel/mdesc.c: In function 'mdesc_next_arc': arch/sparc/kernel/mdesc.c:719:21: error: 'strcmp' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread] 719 | if (strcmp(names + ep->name_offset, arc_type)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/sparc/kernel/mdesc.c:77:33: note: at offset 16 into source object 'mdesc' of size 16 77 | struct mdesc_hdr mdesc; | ^~~~~ cc1: all warnings being treated as errors The issue was initially reported to gcc [1] where it was analized. As suggested, change the struct mdesc_elem * accesses from the end of mdesc to those from the beginning of the data array. Update the prototype of node_block(), name_block() and data_block() since the code really seems to want to do is to compute the address somewhere into the chunk pointed to by hp. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100262 Upstream status: Pending https://www.spinics.net/lists/sparclinux/msg26385.html Signed-off-by: Romain Naour --- ...ringop-overread-warning-to-access-Ma.patch | 154 ++++++++++++++++++ configs/qemu_sparc64_sun4u_defconfig | 3 + 2 files changed, 157 insertions(+) create mode 100644 board/qemu/sparc64-sun4u/patches/linux/0001-sparc64-avoid-stringop-overread-warning-to-access-Ma.patch diff --git a/board/qemu/sparc64-sun4u/patches/linux/0001-sparc64-avoid-stringop-overread-warning-to-access-Ma.patch b/board/qemu/sparc64-sun4u/patches/linux/0001-sparc64-avoid-stringop-overread-warning-to-access-Ma.patch new file mode 100644 index 0000000000..c02704696d --- /dev/null +++ b/board/qemu/sparc64-sun4u/patches/linux/0001-sparc64-avoid-stringop-overread-warning-to-access-Ma.patch @@ -0,0 +1,154 @@ +From 82d91965519c20639c24aadd022b2859461562bc Mon Sep 17 00:00:00 2001 +From: Romain Naour +Date: Tue, 27 Apr 2021 14:54:28 +0200 +Subject: [PATCH] sparc64: avoid stringop-overread warning to access Machine + description datas + +gcc-11 warns about what appears to be an out-of-range array access but +stop the build due to -Werror added to cflags: + +arch/sparc/kernel/mdesc.c: In function 'mdesc_node_by_name': +arch/sparc/kernel/mdesc.c:647:22: error: 'strcmp' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread] + 647 | if (!strcmp(names + ep[ret].name_offset, name)) + | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +arch/sparc/kernel/mdesc.c:77:33: note: at offset 16 into source object 'mdesc' of size 16 + 77 | struct mdesc_hdr mdesc; + | ^~~~~ +arch/sparc/kernel/mdesc.c: In function 'mdesc_get_property': +arch/sparc/kernel/mdesc.c:692:22: error: 'strcmp' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread] + 692 | if (!strcmp(names + ep->name_offset, name)) { + | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +arch/sparc/kernel/mdesc.c:77:33: note: at offset 16 into source object 'mdesc' of size 16 + 77 | struct mdesc_hdr mdesc; + | ^~~~~ +arch/sparc/kernel/mdesc.c: In function 'mdesc_next_arc': +arch/sparc/kernel/mdesc.c:719:21: error: 'strcmp' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread] + 719 | if (strcmp(names + ep->name_offset, arc_type)) + | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +arch/sparc/kernel/mdesc.c:77:33: note: at offset 16 into source object 'mdesc' of size 16 + 77 | struct mdesc_hdr mdesc; + | ^~~~~ +cc1: all warnings being treated as errors + +The issue was initially reported to gcc [1] where it was analized. +As suggested, change the struct mdesc_elem * accesses from the end +of mdesc to those from the beginning of the data array. + +Update the prototype of node_block(), name_block() and data_block() +since the code really seems to want to do is to compute the address +somewhere into the chunk pointed to by hp. + +[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100262 + +Upstream status: Pending +https://www.spinics.net/lists/sparclinux/msg26385.html + +Signed-off-by: Romain Naour +--- + arch/sparc/kernel/mdesc.c | 37 +++++++++++++++++++++---------------- + 1 file changed, 21 insertions(+), 16 deletions(-) + +diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c +index 8e645ddac58e..3403555aa1e2 100644 +--- a/arch/sparc/kernel/mdesc.c ++++ b/arch/sparc/kernel/mdesc.c +@@ -75,6 +75,7 @@ struct mdesc_handle { + refcount_t refcnt; + unsigned int handle_size; + struct mdesc_hdr mdesc; ++ char data[]; + }; + + typedef int (*mdesc_node_info_get_f)(struct mdesc_handle *, u64, +@@ -610,26 +611,30 @@ int mdesc_get_node_info(struct mdesc_handle *hp, u64 node, + } + EXPORT_SYMBOL(mdesc_get_node_info); + +-static struct mdesc_elem *node_block(struct mdesc_hdr *mdesc) ++static struct mdesc_elem *node_block(struct mdesc_handle *hp) + { +- return (struct mdesc_elem *) (mdesc + 1); ++ return (struct mdesc_elem *) hp + offsetof(struct mdesc_handle, data); + } + +-static void *name_block(struct mdesc_hdr *mdesc) ++static void *name_block(struct mdesc_handle *hp) + { +- return ((void *) node_block(mdesc)) + mdesc->node_sz; ++ struct mdesc_hdr *mdesc = &hp->mdesc; ++ ++ return ((void *) node_block(hp)) + mdesc->node_sz; + } + +-static void *data_block(struct mdesc_hdr *mdesc) ++static void *data_block(struct mdesc_handle *hp) + { +- return ((void *) name_block(mdesc)) + mdesc->name_sz; ++ struct mdesc_hdr *mdesc = &hp->mdesc; ++ ++ return ((void *) name_block(hp)) + mdesc->name_sz; + } + + u64 mdesc_node_by_name(struct mdesc_handle *hp, + u64 from_node, const char *name) + { +- struct mdesc_elem *ep = node_block(&hp->mdesc); +- const char *names = name_block(&hp->mdesc); ++ struct mdesc_elem *ep = node_block(hp); ++ const char *names = name_block(hp); + u64 last_node = hp->mdesc.node_sz / 16; + u64 ret; + +@@ -657,15 +662,15 @@ EXPORT_SYMBOL(mdesc_node_by_name); + const void *mdesc_get_property(struct mdesc_handle *hp, u64 node, + const char *name, int *lenp) + { +- const char *names = name_block(&hp->mdesc); ++ const char *names = name_block(hp); + u64 last_node = hp->mdesc.node_sz / 16; +- void *data = data_block(&hp->mdesc); ++ void *data = data_block(hp); + struct mdesc_elem *ep; + + if (node == MDESC_NODE_NULL || node >= last_node) + return NULL; + +- ep = node_block(&hp->mdesc) + node; ++ ep = node_block(hp) + node; + ep++; + for (; ep->tag != MD_NODE_END; ep++) { + void *val = NULL; +@@ -702,8 +707,8 @@ EXPORT_SYMBOL(mdesc_get_property); + + u64 mdesc_next_arc(struct mdesc_handle *hp, u64 from, const char *arc_type) + { +- struct mdesc_elem *ep, *base = node_block(&hp->mdesc); +- const char *names = name_block(&hp->mdesc); ++ struct mdesc_elem *ep, *base = node_block(hp); ++ const char *names = name_block(hp); + u64 last_node = hp->mdesc.node_sz / 16; + + if (from == MDESC_NODE_NULL || from >= last_node) +@@ -728,7 +733,7 @@ EXPORT_SYMBOL(mdesc_next_arc); + + u64 mdesc_arc_target(struct mdesc_handle *hp, u64 arc) + { +- struct mdesc_elem *ep, *base = node_block(&hp->mdesc); ++ struct mdesc_elem *ep, *base = node_block(hp); + + ep = base + arc; + +@@ -738,8 +743,8 @@ EXPORT_SYMBOL(mdesc_arc_target); + + const char *mdesc_node_name(struct mdesc_handle *hp, u64 node) + { +- struct mdesc_elem *ep, *base = node_block(&hp->mdesc); +- const char *names = name_block(&hp->mdesc); ++ struct mdesc_elem *ep, *base = node_block(hp); ++ const char *names = name_block(hp); + u64 last_node = hp->mdesc.node_sz / 16; + + if (node == MDESC_NODE_NULL || node >= last_node) +-- +2.30.2 + diff --git a/configs/qemu_sparc64_sun4u_defconfig b/configs/qemu_sparc64_sun4u_defconfig index cff0c2968a..6a999298eb 100644 --- a/configs/qemu_sparc64_sun4u_defconfig +++ b/configs/qemu_sparc64_sun4u_defconfig @@ -2,6 +2,9 @@ BR2_sparc64=y BR2_sparc_v9=y +# Patches +BR2_GLOBAL_PATCH_DIR="board/qemu/sparc64-sun4u/patches" + # System BR2_SYSTEM_DHCP="eth0" -- 2.31.1