From: Szabolcs Nagy <szabolcs.nagy@arm.com>
To: libc-alpha@sourceware.org
Cc: Jeremy Linton <jeremy.linton@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Will Deacon <will.deacon@arm.com>,
Mark Brown <broonie@kernel.org>,
Florian Weimer <fweimer@redhat.com>,
Kees Cook <keescook@chromium.org>,
Salvatore Mesoraca <s.mesoraca16@gmail.com>,
Lennart Poettering <mzxreary@0pointer.de>,
Topi Miettinen <toiwoton@gmail.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
kernel-hardening@lists.openwall.com,
linux-hardening@vger.kernel.org
Subject: [PATCH 4/4] aarch64: Remove the bti link_map field [BZ #26831]
Date: Tue, 3 Nov 2020 10:26:42 +0000 [thread overview]
Message-ID: <4dadd9c101e32b17e927d56966c54e734ced21ab.1604393169.git.szabolcs.nagy@arm.com> (raw)
In-Reply-To: <cover.1604393169.git.szabolcs.nagy@arm.com>
The bti link_map field is no longer necessary because PROT_BTI
is applied at note processing time immediately instead of in
_dl_open_check based on the bti field.
This is a separate patch that is not expected to be backported
to avoid changing the link_map layout that is libc internal ABI.
---
sysdeps/aarch64/dl-prop.h | 5 +----
sysdeps/aarch64/linkmap.h | 1 -
2 files changed, 1 insertion(+), 5 deletions(-)
diff --git a/sysdeps/aarch64/dl-prop.h b/sysdeps/aarch64/dl-prop.h
index 762bc93733..cf14381e4a 100644
--- a/sysdeps/aarch64/dl-prop.h
+++ b/sysdeps/aarch64/dl-prop.h
@@ -52,10 +52,7 @@ _dl_process_gnu_property (struct link_map *l, int fd, uint32_t type,
unsigned int feature_1 = *(unsigned int *) data;
if (feature_1 & GNU_PROPERTY_AARCH64_FEATURE_1_BTI)
- {
- l->l_mach.bti = true; /* No longer needed. */
- _dl_bti_protect (l, fd);
- }
+ _dl_bti_protect (l, fd);
/* Stop if we processed the property note. */
return 0;
diff --git a/sysdeps/aarch64/linkmap.h b/sysdeps/aarch64/linkmap.h
index 847a03ace2..e921e77495 100644
--- a/sysdeps/aarch64/linkmap.h
+++ b/sysdeps/aarch64/linkmap.h
@@ -22,5 +22,4 @@ struct link_map_machine
{
ElfW(Addr) plt; /* Address of .plt */
void *tlsdesc_table; /* Address of TLS descriptor hash table. */
- bool bti; /* Branch Target Identification is enabled. */
};
--
2.17.1
next prev parent reply other threads:[~2020-11-03 10:27 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-03 10:25 [PATCH 0/4] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) [BZ #26831] Szabolcs Nagy
2020-11-03 10:25 ` [PATCH 1/4] elf: Pass the fd to note processing " Szabolcs Nagy
2020-11-03 10:26 ` [PATCH 2/4] elf: Move note processing after l_phdr is updated " Szabolcs Nagy
2020-11-03 10:38 ` Florian Weimer
2020-11-03 12:36 ` H.J. Lu
2020-11-03 15:04 ` Szabolcs Nagy
2020-11-03 15:27 ` H.J. Lu
2020-11-03 10:26 ` [PATCH 3/4] aarch64: Use mmap to add PROT_BTI instead of mprotect " Szabolcs Nagy
2020-11-03 10:34 ` Florian Weimer
2020-11-03 10:26 ` Szabolcs Nagy [this message]
2020-11-03 17:34 ` [PATCH 0/4] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) " Mark Brown
2020-11-04 5:41 ` Jeremy Linton
2020-11-04 8:57 ` Szabolcs Nagy
2020-11-04 14:41 ` Catalin Marinas
2020-11-04 14:45 ` Florian Weimer
2020-11-04 10:50 ` Mark Brown
2020-11-04 18:47 ` Jeremy Linton
2020-11-04 18:53 ` Mark Brown
2020-11-04 9:02 ` Topi Miettinen
2020-11-04 9:20 ` Will Deacon
2020-11-04 9:29 ` Florian Weimer
2020-11-04 9:55 ` Topi Miettinen
2020-11-04 14:35 ` Catalin Marinas
2020-11-04 15:19 ` Topi Miettinen
2020-11-04 16:08 ` Szabolcs Nagy
2020-11-04 15:20 ` Mark Rutland
2020-11-04 18:59 ` Jeremy Linton
2020-11-05 11:31 ` Szabolcs Nagy
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