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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-03-22 10:54:24 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-02-08 14:13:25 +0100 |
| commit | 57d7f939e7bdd746992f5c318a78697ba837c523 (patch) | |
| tree | 80c01c9c446fc190432798a6d1ecf0c8e5456b57 /arch/s390/kernel/vmlinux.lds.S | |
| parent | s390: report new vector facilities (diff) | |
| download | linux-57d7f939e7bdd746992f5c318a78697ba837c523.tar.xz linux-57d7f939e7bdd746992f5c318a78697ba837c523.zip | |
s390: add no-execute support
Bit 0x100 of a page table, segment table of region table entry
can be used to disallow code execution for the virtual addresses
associated with the entry.
There is one tricky bit, the system call to return from a signal
is part of the signal frame written to the user stack. With a
non-executable stack this would stop working. To avoid breaking
things the protection fault handler checks the opcode that caused
the fault for 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn)
and injects a system call. This is preferable to the alternative
solution with a stub function in the vdso because it works for
vdso=off and statically linked binaries as well.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/vmlinux.lds.S')
| -rw-r--r-- | arch/s390/kernel/vmlinux.lds.S | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index 3667d20e997f..5ccf95396251 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -44,6 +44,7 @@ SECTIONS *(.gnu.warning) } :text = 0x0700 + . = ALIGN(PAGE_SIZE); _etext = .; /* End of text section */ NOTES :text :note @@ -79,7 +80,13 @@ SECTIONS . = ALIGN(PAGE_SIZE); /* Init code and data */ __init_begin = .; - INIT_TEXT_SECTION(PAGE_SIZE) + . = ALIGN(PAGE_SIZE); + .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { + VMLINUX_SYMBOL(_sinittext) = . ; + INIT_TEXT + . = ALIGN(PAGE_SIZE); + VMLINUX_SYMBOL(_einittext) = . ; + } /* * .exit.text is discarded at runtime, not link time, |