From: Laurent Vivier <laurent@vivier.eu>
To: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org,
James Bottomley <James.Bottomley@HansenPartnership.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Laurent Vivier <laurent@vivier.eu>
Subject: [RFC] binfmt_misc: pass binfmt_misc flags to the interpreter
Date: Wed, 13 Nov 2019 17:30:23 +0100 [thread overview]
Message-ID: <20191113163023.12093-1-laurent@vivier.eu> (raw)
It can be useful to the interpreter to know which flags are in use.
For instance, knowing if the preserve-argv[0] is in use would
allow to skip the pathname argument.
This patch uses an unused auxiliary vector, AT_FLAGS, to pass the
content of the binfmt flags (bits for P, F, C, O, ...).
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
fs/binfmt_elf.c | 2 +-
fs/binfmt_elf_fdpic.c | 2 +-
fs/binfmt_misc.c | 2 ++
include/linux/binfmts.h | 2 +-
4 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index c5642bcb6b46..7a34c03e5857 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -250,7 +250,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
NEW_AUX_ENT(AT_BASE, interp_load_addr);
- NEW_AUX_ENT(AT_FLAGS, 0);
+ NEW_AUX_ENT(AT_FLAGS, bprm->fmt_flags);
NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index d86ebd0dcc3d..8fe839be125e 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -647,7 +647,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
- NEW_AUX_ENT(AT_FLAGS, 0);
+ NEW_AUX_ENT(AT_FLAGS, bprm->fmt_flags);
NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index cdb45829354d..b204fa5a2fe4 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -149,6 +149,8 @@ static int load_misc_binary(struct linux_binprm *bprm)
if (!fmt)
return retval;
+ bprm->fmt_flags = fmt->flags;
+
/* Need to be able to load the file after exec */
retval = -ENOENT;
if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index b40fc633f3be..dae0d0d7b84d 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -60,7 +60,7 @@ struct linux_binprm {
different for binfmt_{misc,script} */
unsigned interp_flags;
unsigned interp_data;
- unsigned long loader, exec;
+ unsigned long loader, exec, fmt_flags;
struct rlimit rlim_stack; /* Saved RLIMIT_STACK used during exec. */
--
2.21.0
reply other threads:[~2019-11-13 16:30 UTC|newest]
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