|
Message-Id: <d460a4f7aa4d70cc205f08896ed50b31fcd992df.1606898457.git.szabolcs.nagy@arm.com> Date: Wed, 2 Dec 2020 08:55:14 +0000 From: Szabolcs Nagy <szabolcs.nagy@....com> To: libc-alpha@...rceware.org Cc: Mark Rutland <mark.rutland@....com>, kernel-hardening@...ts.openwall.com, Catalin Marinas <catalin.marinas@....com>, linux-kernel@...r.kernel.org, Jeremy Linton <jeremy.linton@....com>, Mark Brown <broonie@...nel.org>, Topi Miettinen <toiwoton@...il.com>, Will Deacon <will@...nel.org>, linux-arm-kernel@...ts.infradead.org Subject: [PATCH v3 1/2] aarch64: align address for BTI protection [BZ #26988] Handle unaligned executable load segments (the bfd linker is not expected to produce such binaries, but other linkers may). Computing the mapping bounds follows _dl_map_object_from_fd more closely now. Fixes bug 26988. --- v3: - split the last patch in two so this bug is fixed separately. - pushed to nsz/btifix-v3 branch. sysdeps/aarch64/dl-bti.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/sysdeps/aarch64/dl-bti.c b/sysdeps/aarch64/dl-bti.c index 8f4728adce..67d63c8a73 100644 --- a/sysdeps/aarch64/dl-bti.c +++ b/sysdeps/aarch64/dl-bti.c @@ -20,19 +20,22 @@ #include <libintl.h> #include <ldsodefs.h> -static int +static void enable_bti (struct link_map *map, const char *program) { + const size_t pagesz = GLRO(dl_pagesize); const ElfW(Phdr) *phdr; - unsigned prot; for (phdr = map->l_phdr; phdr < &map->l_phdr[map->l_phnum]; ++phdr) if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X)) { - void *start = (void *) (phdr->p_vaddr + map->l_addr); - size_t len = phdr->p_memsz; + size_t vstart = ALIGN_DOWN (phdr->p_vaddr, pagesz); + size_t vend = ALIGN_UP (phdr->p_vaddr + phdr->p_filesz, pagesz); + off_t off = ALIGN_DOWN (phdr->p_offset, pagesz); + void *start = (void *) (vstart + map->l_addr); + size_t len = vend - vstart; - prot = PROT_EXEC | PROT_BTI; + unsigned prot = PROT_EXEC | PROT_BTI; if (phdr->p_flags & PF_R) prot |= PROT_READ; if (phdr->p_flags & PF_W) @@ -48,7 +51,6 @@ enable_bti (struct link_map *map, const char *program) N_("mprotect failed to turn on BTI")); } } - return 0; } /* Enable BTI for MAP and its dependencies. */ -- 2.17.1
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.