The patch titled
Subject: fs/binfmt_elf.c: extract PROT_* calculations
has been added to the -mm tree. Its filename is
elf-extract-prot_-calculations.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/elf-extract-prot_-calculations.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/elf-extract-prot_-calculations.patch
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------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: fs/binfmt_elf.c: extract PROT_* calculations
There are two places where mapping protections are calculated: one for
executable, another one for interpreter -- take them out.
ELF read and execute permissions are interchanged with Linux PROT_READ and
PROT_EXEC, microoptimizations are welcome!
Link: http://lkml.kernel.org/r/20190417213413.GB26474@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_elf.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
--- a/fs/binfmt_elf.c~elf-extract-prot_-calculations
+++ a/fs/binfmt_elf.c
@@ -524,6 +524,19 @@ static inline int arch_check_elf(struct
#endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
+static inline int make_prot(u32 p_flags)
+{
+ int prot = 0;
+
+ if (p_flags & PF_R)
+ prot |= PROT_READ;
+ if (p_flags & PF_W)
+ prot |= PROT_WRITE;
+ if (p_flags & PF_X)
+ prot |= PROT_EXEC;
+ return prot;
+}
+
/* This is much more generalized than the library routine read function,
so we keep this separate. Technically the library read function
is only provided so that we can read a.out libraries that have
@@ -563,16 +576,10 @@ static unsigned long load_elf_interp(str
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 = 0;
+ int elf_prot = make_prot(eppnt->p_flags);
unsigned long vaddr = 0;
unsigned long k, map_addr;
- if (eppnt->p_flags & PF_R)
- elf_prot = PROT_READ;
- if (eppnt->p_flags & PF_W)
- elf_prot |= PROT_WRITE;
- if (eppnt->p_flags & PF_X)
- elf_prot |= PROT_EXEC;
vaddr = eppnt->p_vaddr;
if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
elf_type |= MAP_FIXED_NOREPLACE;
@@ -891,7 +898,7 @@ out_free_interp:
the correct location in memory. */
for(i = 0, elf_ppnt = elf_phdata;
i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
- int elf_prot = 0, elf_flags, elf_fixed = MAP_FIXED_NOREPLACE;
+ int elf_prot, elf_flags, elf_fixed = MAP_FIXED_NOREPLACE;
unsigned long k, vaddr;
unsigned long total_size = 0;
@@ -932,12 +939,7 @@ out_free_interp:
elf_fixed = MAP_FIXED;
}
- if (elf_ppnt->p_flags & PF_R)
- elf_prot |= PROT_READ;
- if (elf_ppnt->p_flags & PF_W)
- elf_prot |= PROT_WRITE;
- if (elf_ppnt->p_flags & PF_X)
- elf_prot |= PROT_EXEC;
+ elf_prot = make_prot(elf_ppnt->p_flags);
elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
proc-fix-map_files-test-on-f29.patch
proc-fixup-proc-pid-vm-test.patch
ramfs-support-o_tmpfile.patch
elf-make-scope-of-pos-variable-smaller.patch
elf-free-pt_interp-filename-asap.patch
elf-delete-trailing-return-in-functions-returning-void.patch
elf-save-1-indent-level.patch
elf-move-variables-initialization-closer-to-their-usage.patch
elf-extract-prot_-calculations.patch
exec-move-recursion_depth-out-of-critical-sections.patch
