From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>
Cc: "Alexander Viro" <viro@zeniv.linux.org.uk>,
"Paul Elliott" <paul.elliott@arm.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Yu-cheng Yu" <yu-cheng.yu@intel.com>,
"Amit Kachhap" <amit.kachhap@arm.com>,
"Vincenzo Frascino" <vincenzo.frascino@arm.com>,
"Marc Zyngier" <maz@kernel.org>,
"Eugene Syromiatnikov" <esyr@redhat.com>,
"Szabolcs Nagy" <szabolcs.nagy@arm.com>,
"H . J . Lu " <hjl.tools@gmail.com>,
"Andrew Jones" <drjones@redhat.com>,
"Kees Cook" <keescook@chromium.org>,
"Arnd Bergmann" <arnd@arndb.de>, "Jann Horn" <jannh@google.com>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Kristina Martšenko" <kristina.martsenko@arm.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Florian Weimer" <fweimer@redhat.com>,
"Sudakshina Das" <sudi.das@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
"Dave Martin" <Dave.Martin@arm.com>,
"Mark Brown" <broonie@kernel.org>
Subject: [PATCH v6 04/11] elf: Allow arch to tweak initial mmap prot flags
Date: Wed, 12 Feb 2020 19:28:59 +0000 [thread overview]
Message-ID: <20200212192906.53366-5-broonie@kernel.org> (raw)
In-Reply-To: <20200212192906.53366-1-broonie@kernel.org>
From: Dave Martin <Dave.Martin@arm.com>
An arch may want to tweak the mmap prot flags for an
ELFexecutable's initial mappings. For example, arm64 is going to
need to add PROT_BTI for executable pages in an ELF process whose
executable is marked as using Branch Target Identification (an
ARMv8.5-A control flow integrity feature).
So that this can be done in a generic way, add a hook
arch_elf_adjust_prot() to modify the prot flags as desired: arches
can select CONFIG_HAVE_ELF_PROT and implement their own backend
where necessary.
By default, leave the prot flags unchanged.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
fs/Kconfig.binfmt | 3 +++
fs/binfmt_elf.c | 18 ++++++++++++------
include/linux/elf.h | 12 ++++++++++++
3 files changed, 27 insertions(+), 6 deletions(-)
diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index d2cfe0729a73..2358368319b8 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -36,6 +36,9 @@ config COMPAT_BINFMT_ELF
config ARCH_BINFMT_ELF_STATE
bool
+config ARCH_HAVE_ELF_PROT
+ bool
+
config ARCH_USE_GNU_PROPERTY
bool
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 1fb67e506b68..cceb29d6ef1d 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -544,7 +544,8 @@ static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
#endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
-static inline int make_prot(u32 p_flags)
+static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state,
+ bool has_interp, bool is_interp)
{
int prot = 0;
@@ -554,7 +555,8 @@ static inline int make_prot(u32 p_flags)
prot |= PROT_WRITE;
if (p_flags & PF_X)
prot |= PROT_EXEC;
- return prot;
+
+ return arch_elf_adjust_prot(prot, arch_state, has_interp, is_interp);
}
/* This is much more generalized than the library routine read function,
@@ -564,7 +566,8 @@ static inline int make_prot(u32 p_flags)
static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
struct file *interpreter,
- unsigned long no_base, struct elf_phdr *interp_elf_phdata)
+ unsigned long no_base, struct elf_phdr *interp_elf_phdata,
+ struct arch_elf_state *arch_state)
{
struct elf_phdr *eppnt;
unsigned long load_addr = 0;
@@ -596,7 +599,8 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
if (eppnt->p_type == PT_LOAD) {
int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
- int elf_prot = make_prot(eppnt->p_flags);
+ int elf_prot = make_prot(eppnt->p_flags, arch_state,
+ true, true);
unsigned long vaddr = 0;
unsigned long k, map_addr;
@@ -1041,7 +1045,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
}
}
- elf_prot = make_prot(elf_ppnt->p_flags);
+ elf_prot = make_prot(elf_ppnt->p_flags, &arch_state,
+ !!interpreter, false);
elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
@@ -1184,7 +1189,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
if (interpreter) {
elf_entry = load_elf_interp(&loc->interp_elf_ex,
interpreter,
- load_bias, interp_elf_phdata);
+ load_bias, interp_elf_phdata,
+ &arch_state);
if (!IS_ERR((void *)elf_entry)) {
/*
* load_elf_interp() returns relocation
diff --git a/include/linux/elf.h b/include/linux/elf.h
index 7bdc6da160c7..1b6e8955c597 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -83,4 +83,16 @@ extern int arch_parse_elf_property(u32 type, const void *data, size_t datasz,
bool compat, struct arch_elf_state *arch);
#endif
+#ifdef CONFIG_ARCH_HAVE_ELF_PROT
+int arch_elf_adjust_prot(int prot, const struct arch_elf_state *state,
+ bool has_interp, bool is_interp);
+#else
+static inline int arch_elf_adjust_prot(int prot,
+ const struct arch_elf_state *state,
+ bool has_interp, bool is_interp)
+{
+ return prot;
+}
+#endif
+
#endif /* _LINUX_ELF_H */
--
2.20.1
next prev parent reply other threads:[~2020-02-12 19:29 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 19:28 [PATCH v6 00/11] arm64: Branch Target Identification support Mark Brown
2020-02-12 19:28 ` [PATCH v6 01/11] ELF: UAPI and Kconfig additions for ELF program properties Mark Brown
2020-02-26 5:49 ` Kees Cook
2020-02-26 11:20 ` Mark Brown
2020-02-12 19:28 ` [PATCH v6 02/11] ELF: Add ELF program property parsing support Mark Brown
2020-02-12 19:28 ` [PATCH v6 03/11] arm64: Basic Branch Target Identification support Mark Brown
2020-02-12 19:28 ` Mark Brown [this message]
2020-02-12 19:29 ` [PATCH v6 05/11] arm64: elf: Enable BTI at exec based on ELF program properties Mark Brown
2020-02-25 13:28 ` Amit Kachhap
2020-02-25 17:27 ` Mark Brown
2020-02-26 5:47 ` Kees Cook
2020-02-12 19:29 ` [PATCH v6 06/11] arm64: BTI: Decode BTYPE bits when printing PSTATE Mark Brown
2020-02-12 19:29 ` [PATCH v6 07/11] arm64: unify native/compat instruction skipping Mark Brown
2020-02-12 19:29 ` [PATCH v6 08/11] arm64: traps: Shuffle code to eliminate forward declarations Mark Brown
2020-02-12 19:29 ` [PATCH v6 09/11] arm64: BTI: Reset BTYPE when skipping emulated instructions Mark Brown
2020-02-12 19:29 ` [PATCH v6 10/11] KVM: " Mark Brown
2020-02-15 11:56 ` Marc Zyngier
2020-02-12 19:29 ` [PATCH v6 11/11] arm64: mm: Display guarded pages in ptdump Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200212192906.53366-5-broonie@kernel.org \
--to=broonie@kernel.org \
--cc=Dave.Martin@arm.com \
--cc=amit.kachhap@arm.com \
--cc=arnd@arndb.de \
--cc=catalin.marinas@arm.com \
--cc=drjones@redhat.com \
--cc=esyr@redhat.com \
--cc=fweimer@redhat.com \
--cc=hjl.tools@gmail.com \
--cc=jannh@google.com \
--cc=keescook@chromium.org \
--cc=kristina.martsenko@arm.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=paul.elliott@arm.com \
--cc=peterz@infradead.org \
--cc=richard.henderson@linaro.org \
--cc=sudi.das@arm.com \
--cc=szabolcs.nagy@arm.com \
--cc=tglx@linutronix.de \
--cc=vincenzo.frascino@arm.com \
--cc=viro@zeniv.linux.org.uk \
--cc=will@kernel.org \
--cc=yu-cheng.yu@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).