From: Szabolcs Nagy <szabolcs.nagy@arm.com>
To: libc-alpha@sourceware.org
Cc: Mark Rutland <mark.rutland@arm.com>,
kernel-hardening@lists.openwall.com,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org,
Jeremy Linton <jeremy.linton@arm.com>,
Mark Brown <broonie@kernel.org>,
Topi Miettinen <toiwoton@gmail.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 1/2] aarch64: align address for BTI protection [BZ #26988]
Date: Wed, 2 Dec 2020 08:55:14 +0000 [thread overview]
Message-ID: <d460a4f7aa4d70cc205f08896ed50b31fcd992df.1606898457.git.szabolcs.nagy@arm.com> (raw)
In-Reply-To: <ebce134991eae4261bbb32572a2062d3ca56e674.1606319495.git.szabolcs.nagy@arm.com>
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
next prev parent reply other threads:[~2020-12-02 8:55 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-27 13:19 [PATCH v2 0/6] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) [BZ #26831] Szabolcs Nagy
2020-11-27 13:19 ` [PATCH v2 1/6] aarch64: Fix missing BTI protection from dependencies [BZ #26926] Szabolcs Nagy
2020-12-10 17:51 ` Adhemerval Zanella
2020-12-11 15:33 ` Szabolcs Nagy
2020-11-27 13:20 ` [PATCH v2 2/6] elf: lose is closely tied to _dl_map_object_from_fd Szabolcs Nagy
2020-12-10 17:57 ` Adhemerval Zanella
2020-12-11 12:12 ` Szabolcs Nagy
2020-11-27 13:20 ` [PATCH v2 3/6] elf: Fix failure handling in _dl_map_object_from_fd Szabolcs Nagy
2020-12-10 18:25 ` Adhemerval Zanella
2020-12-11 9:32 ` Szabolcs Nagy
2020-11-27 13:20 ` [PATCH v2 4/6] elf: Move note processing after l_phdr is updated Szabolcs Nagy
2020-12-10 18:30 ` Adhemerval Zanella
2020-11-27 13:21 ` [PATCH v2 5/6] elf: Pass the fd to note processing Szabolcs Nagy
2020-12-10 18:35 ` Adhemerval Zanella
2020-11-27 13:21 ` [PATCH v2 6/6] aarch64: Use mmap to add PROT_BTI instead of mprotect [BZ #26831] Szabolcs Nagy
2020-12-02 8:55 ` Szabolcs Nagy [this message]
2020-12-10 18:49 ` [PATCH v3 1/2] aarch64: align address for BTI protection [BZ #26988] Adhemerval Zanella
2020-12-02 8:55 ` [PATCH v3 2/2] aarch64: Use mmap to add PROT_BTI instead of mprotect [BZ #26831] Szabolcs Nagy
2020-12-10 19:12 ` Adhemerval Zanella
2020-11-30 15:56 ` [PATCH v2 0/6] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) " Szabolcs Nagy
2020-12-03 17:30 ` Catalin Marinas
2020-12-07 20:03 ` Szabolcs Nagy
2020-12-11 17:46 ` Catalin Marinas
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