aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/xen
AgeCommit message (Collapse)AuthorFilesLines
2020-06-11x86/entry: Switch XEN/PV hypercall entry to IDTENTRYThomas Gleixner5-9/+13
Convert the XEN/PV hypercall to IDTENTRY: - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64-bit - Remove the open coded ASM entry code in 32-bit - Remove the old prototypes The handler stubs need to stay in ASM code as they need corner case handling and adjustment of the stack pointer. Provide a new C function which invokes the entry/exit handling and calls into the XEN handler on the interrupt stack if required. The exit code is slightly different from the regular idtentry_exit() on non-preemptible kernels. If the hypercall is preemptible and need_resched() is set then XEN provides a preempt hypercall scheduling function. Move this functionality into the entry code so it can use the existing idtentry functionality. [ mingo: Build fixes. ] Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Juergen Gross <[email protected]> Tested-by: Juergen Gross <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert double fault exception to IDTENTRY_DFThomas Gleixner2-3/+3
Convert #DF to IDTENTRY_DF - Implement the C entry point with DEFINE_IDTENTRY_DF - Emit the ASM stub with DECLARE_IDTENTRY_DF on 64bit - Remove the ASM idtentry in 64bit - Adjust the 32bit shim code - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Debug exception to IDTENTRY_DBThomas Gleixner2-3/+3
Convert #DB to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY_DB - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert NMI to IDTENTRY_NMIThomas Gleixner2-2/+7
Convert #NMI to IDTENTRY_NMI: - Implement the C entry point with DEFINE_IDTENTRY_NMI - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Machine Check to IDTENTRY_ISTThomas Gleixner2-2/+2
Convert #MC to IDTENTRY_MCE: - Implement the C entry points with DEFINE_IDTENTRY_MCE - Emit the ASM stub with DECLARE_IDTENTRY_MCE - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the error code from *machine_check_vector() as it is always 0 and not used by any of the functions it can point to. Fixup all the functions as well. No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert INT3 exception to IDTENTRY_RAWThomas Gleixner2-2/+2
Convert #BP to IDTENTRY_RAW: - Implement the C entry point with DEFINE_IDTENTRY_RAW - Invoke idtentry_enter/exit() from the function body - Emit the ASM stub with DECLARE_IDTENTRY_RAW - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. This could be a plain IDTENTRY, but as Peter pointed out INT3 is broken vs. the static key in the context tracking code as this static key might be in the state of being patched and has an int3 which would recurse forever. IDTENTRY_RAW is therefore chosen to allow addressing this issue without lots of code churn. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/32: Convert IRET exception to IDTENTRY_SWThomas Gleixner1-1/+1
Convert the IRET exception handler to IDTENTRY_SW. This is slightly different than the conversions of hardware exceptions as the IRET exception is invoked via an exception table when IRET faults. So it just uses the IDTENTRY_SW mechanism for consistency. It does not emit ASM code as it does not fit the other idtentry exceptions. - Implement the C entry point with DEFINE_IDTENTRY_SW() which maps to DEFINE_IDTENTRY() - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert SIMD coprocessor error exception to IDTENTRYThomas Gleixner2-2/+2
Convert #XF to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Handle INVD_BUG in C - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Alignment check exception to IDTENTRYThomas Gleixner2-2/+2
Convert #AC to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Coprocessor error exception to IDTENTRYThomas Gleixner2-2/+2
Convert #MF to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Spurious interrupt bug exception to IDTENTRYThomas Gleixner2-2/+2
Convert #SPURIOUS to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert General protection exception to IDTENTRYThomas Gleixner2-2/+2
Convert #GP to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Stack segment exception to IDTENTRYThomas Gleixner2-2/+2
Convert #SS to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Segment not present exception to IDTENTRYThomas Gleixner2-2/+2
Convert #NP to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Invalid TSS exception to IDTENTRYThomas Gleixner2-2/+2
Convert #TS to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Coprocessor segment overrun exception to IDTENTRYThomas Gleixner2-2/+2
Convert #OLD_MF to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Device not available exception to IDTENTRYThomas Gleixner2-2/+2
Convert #NM to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Invalid Opcode exception to IDTENTRYThomas Gleixner2-2/+2
Convert #UD to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Fixup the FOOF bug call in fault.c - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Bounds exception to IDTENTRYThomas Gleixner2-2/+2
Convert #BR to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Overflow exception to IDTENTRYThomas Gleixner2-2/+2
Convert #OF to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Divide Error to IDTENTRYThomas Gleixner2-2/+7
Convert #DE to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/xen: Split HVM vector callback setup and interrupt gate allocationVitaly Kuznetsov2-2/+2
As a preparatory change for making alloc_intr_gate() __init split xen_callback_vector() into callback vector setup via hypercall (xen_setup_callback_vector()) and interrupt gate allocation (xen_alloc_callback_vector()). xen_setup_callback_vector() is being called twice: on init and upon system resume from xen_hvm_post_suspend(). alloc_intr_gate() only needs to be called once. Suggested-by: Thomas Gleixner <[email protected]> Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-09mm: reorder includes after introduction of linux/pgtable.hMike Rapoport2-1/+2
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s <file> <header>" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include <linux/%s>" % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include <linux/"): in_hdrs = True elif not moved and in_hdrs: moved = True print hdr_to_move print line Signed-off-by: Mike Rapoport <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Cain <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chris Zankel <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greentime Hu <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Guan Xuetao <[email protected]> Cc: Guo Ren <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Helge Deller <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Ley Foon Tan <[email protected]> Cc: Mark Salter <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Matt Turner <[email protected]> Cc: Max Filippov <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Michal Simek <[email protected]> Cc: Nick Hu <[email protected]> Cc: Paul Walmsley <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rich Felker <[email protected]> Cc: Russell King <[email protected]> Cc: Stafford Horne <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: Vincent Chen <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yoshinori Sato <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-06-09mm: introduce include/linux/pgtable.hMike Rapoport2-2/+1
The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Cain <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chris Zankel <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greentime Hu <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Guan Xuetao <[email protected]> Cc: Guo Ren <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Helge Deller <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Ley Foon Tan <[email protected]> Cc: Mark Salter <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Matt Turner <[email protected]> Cc: Max Filippov <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Michal Simek <[email protected]> Cc: Nick Hu <[email protected]> Cc: Paul Walmsley <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rich Felker <[email protected]> Cc: Russell King <[email protected]> Cc: Stafford Horne <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: Vincent Chen <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yoshinori Sato <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport2-2/+0
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Cain <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chris Zankel <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greentime Hu <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Guan Xuetao <[email protected]> Cc: Guo Ren <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Helge Deller <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Ley Foon Tan <[email protected]> Cc: Mark Salter <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Matt Turner <[email protected]> Cc: Max Filippov <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Michal Simek <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Nick Hu <[email protected]> Cc: Paul Walmsley <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rich Felker <[email protected]> Cc: Russell King <[email protected]> Cc: Stafford Horne <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: Vincent Chen <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yoshinori Sato <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-05-25Merge tag 'efi-changes-for-v5.8' of ↵Ingo Molnar1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core More EFI changes for v5.8: - Rename pr_efi/pr_efi_err to efi_info/efi_err, and use them consistently - Simplify and unify initrd loading - Parse the builtin command line on x86 (if provided) - Implement printk() support, including support for wide character strings - Some fixes for issues introduced by the first batch of v5.8 changes - Fix a missing prototypes warning - Simplify GDT handling in early mixed mode thunking code - Some other minor fixes and cleanups Conflicts: drivers/firmware/efi/libstub/efistub.h Signed-off-by: Ingo Molnar <[email protected]>
2020-05-20efi/libstub: Add definitions for console input and eventsArvind Sankar1-1/+1
Add the required typedefs etc for using con_in's simple text input protocol, and for using the boottime event services. Also add the prototype for the "stall" boot service. Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-05-15x86: Fix early boot crash on gcc-10, third tryBorislav Petkov1-0/+1
... or the odyssey of trying to disable the stack protector for the function which generates the stack canary value. The whole story started with Sergei reporting a boot crash with a kernel built with gcc-10: Kernel panic — not syncing: stack-protector: Kernel stack is corrupted in: start_secondary CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5—00235—gfffb08b37df9 #139 Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M—D3H, BIOS F12 11/14/2013 Call Trace: dump_stack panic ? start_secondary __stack_chk_fail start_secondary secondary_startup_64 -—-[ end Kernel panic — not syncing: stack—protector: Kernel stack is corrupted in: start_secondary This happens because gcc-10 tail-call optimizes the last function call in start_secondary() - cpu_startup_entry() - and thus emits a stack canary check which fails because the canary value changes after the boot_init_stack_canary() call. To fix that, the initial attempt was to mark the one function which generates the stack canary with: __attribute__((optimize("-fno-stack-protector"))) ... start_secondary(void *unused) however, using the optimize attribute doesn't work cumulatively as the attribute does not add to but rather replaces previously supplied optimization options - roughly all -fxxx options. The key one among them being -fno-omit-frame-pointer and thus leading to not present frame pointer - frame pointer which the kernel needs. The next attempt to prevent compilers from tail-call optimizing the last function call cpu_startup_entry(), shy of carving out start_secondary() into a separate compilation unit and building it with -fno-stack-protector, was to add an empty asm(""). This current solution was short and sweet, and reportedly, is supported by both compilers but we didn't get very far this time: future (LTO?) optimization passes could potentially eliminate this, which leads us to the third attempt: having an actual memory barrier there which the compiler cannot ignore or move around etc. That should hold for a long time, but hey we said that about the other two solutions too so... Reported-by: Sergei Trofimovich <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Tested-by: Kalle Valo <[email protected]> Cc: <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-04-10Merge tag 'for-linus-5.7-rc1b-tag' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull more xen updates from Juergen Gross: - two cleanups - fix a boot regression introduced in this merge window - fix wrong use of memory allocation flags * tag 'for-linus-5.7-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: fix booting 32-bit pv guest x86/xen: make xen_pvmmu_arch_setup() static xen/blkfront: fix memory allocation flags in blkfront_setup_indirect() xen: Use evtchn_type_t as a type for event channels
2020-04-09x86/xen: fix booting 32-bit pv guestJuergen Gross1-1/+1
Commit 2f62f36e62daec ("x86/xen: Make the boot CPU idle task reliable") introduced a regression for booting 32 bit Xen PV guests: the address of the initial stack needs to be a virtual one. Fixes: 2f62f36e62daec ("x86/xen: Make the boot CPU idle task reliable") Signed-off-by: Juergen Gross <[email protected]> Reviewed-by: Boris Ostrovsky <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Juergen Gross <[email protected]>
2020-04-08x86/xen: make xen_pvmmu_arch_setup() staticJason Yan1-1/+1
Fix the following sparse warning: arch/x86/xen/setup.c:998:12: warning: symbol 'xen_pvmmu_arch_setup' was not declared. Should it be static? Reported-by: Hulk Robot <[email protected]> Signed-off-by: Jason Yan <[email protected]> Reviewed-by: Juergen Gross <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Juergen Gross <[email protected]>
2020-04-03Merge tag 'for-linus-5.7-rc1-tag' of ↵Linus Torvalds2-3/+18
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - a cleanup patch removing an unused function - a small fix for the xen pciback driver - a series for making the unwinder hyppay with the Xen PV guest idle task stacks * tag 'for-linus-5.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: Make the secondary CPU idle tasks reliable x86/xen: Make the boot CPU idle task reliable xen-pciback: fix INTERRUPT_TYPE_* defines xen/xenbus: remove unused xenbus_map_ring()
2020-03-30Merge tag 'timers-core-2020-03-30' of ↵Linus Torvalds1-14/+22
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timekeeping and timer updates from Thomas Gleixner: "Core: - Consolidation of the vDSO build infrastructure to address the difficulties of cross-builds for ARM64 compat vDSO libraries by restricting the exposure of header content to the vDSO build. This is achieved by splitting out header content into separate headers. which contain only the minimaly required information which is necessary to build the vDSO. These new headers are included from the kernel headers and the vDSO specific files. - Enhancements to the generic vDSO library allowing more fine grained control over the compiled in code, further reducing architecture specific storage and preparing for adopting the generic library by PPC. - Cleanup and consolidation of the exit related code in posix CPU timers. - Small cleanups and enhancements here and there Drivers: - The obligatory new drivers: Ingenic JZ47xx and X1000 TCU support - Correct the clock rate of PIT64b global clock - setup_irq() cleanup - Preparation for PWM and suspend support for the TI DM timer - Expand the fttmr010 driver to support ast2600 systems - The usual small fixes, enhancements and cleanups all over the place" * tag 'timers-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits) Revert "clocksource/drivers/timer-probe: Avoid creating dead devices" vdso: Fix clocksource.h macro detection um: Fix header inclusion arm64: vdso32: Enable Clang Compilation lib/vdso: Enable common headers arm: vdso: Enable arm to use common headers x86/vdso: Enable x86 to use common headers mips: vdso: Enable mips to use common headers arm64: vdso32: Include common headers in the vdso library arm64: vdso: Include common headers in the vdso library arm64: Introduce asm/vdso/processor.h arm64: vdso32: Code clean up linux/elfnote.h: Replace elf.h with UAPI equivalent scripts: Fix the inclusion order in modpost common: Introduce processor.h linux/ktime.h: Extract common header for vDSO linux/jiffies.h: Extract common header for vDSO linux/time64.h: Extract common header for vDSO linux/time32.h: Extract common header for vDSO linux/time.h: Extract common header for vDSO ...
2020-03-30x86/xen: Make the secondary CPU idle tasks reliableMiroslav Benes2-1/+12
The unwinder reports the secondary CPU idle tasks' stack on XEN PV as unreliable, which affects at least live patching. cpu_initialize_context() sets up the context of the CPU through VCPUOP_initialise hypercall. After it is woken up, the idle task starts in cpu_bringup_and_idle() function and its stack starts at the offset right below pt_regs. The unwinder correctly detects the end of stack there but it is confused by NULL return address in the last frame. Introduce a wrapper in assembly, which just calls cpu_bringup_and_idle(). The return address is thus pushed on the stack and the wrapper contains the annotation hint for the unwinder regarding the stack state. Signed-off-by: Miroslav Benes <[email protected]> Reviewed-by: Juergen Gross <[email protected]> Signed-off-by: Juergen Gross <[email protected]>
2020-03-30x86/xen: Make the boot CPU idle task reliableMiroslav Benes1-2/+6
The unwinder reports the boot CPU idle task's stack on XEN PV as unreliable, which affects at least live patching. There are two reasons for this. First, the task does not follow the x86 convention that its stack starts at the offset right below saved pt_regs. It allows the unwinder to easily detect the end of the stack and verify it. Second, startup_xen() function does not store the return address before jumping to xen_start_kernel() which confuses the unwinder. Amend both issues by moving the starting point of initial stack in startup_xen() and storing the return address before the jump, which is exactly what call instruction does. Signed-off-by: Miroslav Benes <[email protected]> Reviewed-by: Juergen Gross <[email protected]> Signed-off-by: Juergen Gross <[email protected]>
2020-03-25x86/smp: Replace cpu_up/down() with add/remove_cpu()Qais Yousef1-1/+1
The core device API performs extra housekeeping bits that are missing from directly calling cpu_up/down(). See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") for an example description of what might go wrong. This also prepares to make cpu_up/down() a private interface of the CPU subsystem. Signed-off-by: Qais Yousef <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-29x86/ioperm: Add new paravirt function update_io_bitmap()Juergen Gross1-0/+25
Commit 111e7b15cf10f6 ("x86/ioperm: Extend IOPL config to control ioperm() as well") reworked the iopl syscall to use I/O bitmaps. Unfortunately this broke Xen PV domains using that syscall as there is currently no I/O bitmap support in PV domains. Add I/O bitmap support via a new paravirt function update_io_bitmap which Xen PV domains can use to update their I/O bitmaps via a hypercall. Fixes: 111e7b15cf10f6 ("x86/ioperm: Extend IOPL config to control ioperm() as well") Reported-by: Jan Beulich <[email protected]> Signed-off-by: Juergen Gross <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Jan Beulich <[email protected]> Reviewed-by: Jan Beulich <[email protected]> Cc: <[email protected]> # 5.5 Link: https://lkml.kernel.org/r/[email protected]
2020-02-21Merge tag 'for-linus-5.6-rc3-tag' of ↵Linus Torvalds1-3/+4
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: "Two small fixes for Xen: - a fix to avoid warnings with new gcc - a fix for incorrectly disabled interrupts when calling _cond_resched()" * tag 'for-linus-5.6-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: Enable interrupts when calling _cond_resched() x86/xen: Distribute switch variables for initialization
2020-02-20x86/xen: Distribute switch variables for initializationKees Cook1-3/+4
Variables declared in a switch statement before any case statements cannot be automatically initialized with compiler instrumentation (as they are not part of any execution flow). With GCC's proposed automatic stack variable initialization feature, this triggers a warning (and they don't get initialized). Clang's automatic stack variable initialization (via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also doesn't initialize such variables[1]. Note that these warnings (or silent skipping) happen before the dead-store elimination optimization phase, so even when the automatic initializations are later elided in favor of direct initializations, the warnings remain. To avoid these problems, move such variables into the "case" where they're used or lift them up into the main function body. arch/x86/xen/enlighten_pv.c: In function ‘xen_write_msr_safe’: arch/x86/xen/enlighten_pv.c:904:12: warning: statement will never be executed [-Wswitch-unreachable] 904 | unsigned which; | ^~~~~ [1] https://bugs.llvm.org/show_bug.cgi?id=44916 Signed-off-by: Kees Cook <[email protected]> Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Juergen Gross <[email protected]> [boris: made @which an 'unsigned int'] Signed-off-by: Boris Ostrovsky <[email protected]>
2020-02-17x86/vdso: Use generic VDSO clock mode storageThomas Gleixner1-10/+11
Switch to the generic VDSO clock mode storage. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Vincenzo Frascino <[email protected]> (VDSO parts) Acked-by: Juergen Gross <[email protected]> (Xen parts) Acked-by: Paolo Bonzini <[email protected]> (KVM parts) Link: https://lkml.kernel.org/r/[email protected]
2020-02-17x86/vdso: Move VDSO clocksource state tracking to callbackThomas Gleixner1-5/+12
All architectures which use the generic VDSO code have their own storage for the VDSO clock mode. That's pointless and just requires duplicate code. X86 abuses the function which retrieves the architecture specific clock mode storage to mark the clocksource as used in the VDSO. That's silly because this is invoked on every tick when the VDSO data is updated. Move this functionality to the clocksource::enable() callback so it gets invoked once when the clocksource is installed. This allows to make the clock mode storage generic. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Michael Kelley <[email protected]> (Hyper-V parts) Reviewed-by: Vincenzo Frascino <[email protected]> (VDSO parts) Acked-by: Juergen Gross <[email protected]> (Xen parts) Link: https://lkml.kernel.org/r/[email protected]
2020-02-09Merge tag 'x86-urgent-2020-02-09' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of fixes for X86: - Ensure that the PIT is set up when the local APIC is disable or configured in legacy mode. This is caused by an ordering issue introduced in the recent changes which skip PIT initialization when the TSC and APIC frequencies are already known. - Handle malformed SRAT tables during early ACPI parsing which caused an infinite loop anda boot hang. - Fix a long standing race in the affinity setting code which affects PCI devices with non-maskable MSI interrupts. The problem is caused by the non-atomic writes of the MSI address (destination APIC id) and data (vector) fields which the device uses to construct the MSI message. The non-atomic writes are mandated by PCI. If both fields change and the device raises an interrupt after writing address and before writing data, then the MSI block constructs a inconsistent message which causes interrupts to be lost and subsequent malfunction of the device. The fix is to redirect the interrupt to the new vector on the current CPU first and then switch it over to the new target CPU. This allows to observe an eventually raised interrupt in the transitional stage (old CPU, new vector) to be observed in the APIC IRR and retriggered on the new target CPU and the new vector. The potential spurious interrupts caused by this are harmless and can in the worst case expose a buggy driver (all handlers have to be able to deal with spurious interrupts as they can and do happen for various reasons). - Add the missing suspend/resume mechanism for the HYPERV hypercall page which prevents resume hibernation on HYPERV guests. This change got lost before the merge window. - Mask the IOAPIC before disabling the local APIC to prevent potentially stale IOAPIC remote IRR bits which cause stale interrupt lines after resume" * tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Mask IOAPIC entries when disabling the local APIC x86/hyperv: Suspend/resume the hypercall page for hibernation x86/apic/msi: Plug non-maskable MSI affinity race x86/boot: Handle malformed SRAT tables during early ACPI parsing x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
2020-01-29x86/timer: Don't skip PIT setup when APIC is disabled or in legacy modeThomas Gleixner1-0/+1
Tony reported a boot regression caused by the recent workaround for systems which have a disabled (clock gate off) PIT. On his machine the kernel fails to initialize the PIT because apic_needs_pit() does not take into account whether the local APIC interrupt delivery mode will actually allow to setup and use the local APIC timer. This should be easy to reproduce with acpi=off on the command line which also disables HPET. Due to the way the PIT/HPET and APIC setup ordering works (APIC setup can require working PIT/HPET) the information is not available at the point where apic_needs_pit() makes this decision. To address this, split out the interrupt mode selection from apic_intr_mode_init(), invoke the selection before making the decision whether PIT is required or not, and add the missing checks into apic_needs_pit(). Fixes: c8c4076723da ("x86/timer: Skip PIT initialization on modern chipsets") Reported-by: Anthony Buckley <[email protected]> Tested-by: Anthony Buckley <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Cc: Daniel Drake <[email protected]> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206125 Link: https://lore.kernel.org/r/[email protected]
2020-01-28Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups all around the map" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU/AMD: Remove amd_get_topology_early() x86/tsc: Remove redundant assignment x86/crash: Use resource_size() x86/cpu: Add a missing prototype for arch_smt_update() x86/nospec: Remove unused RSB_FILL_LOOPS x86/vdso: Provide missing include file x86/Kconfig: Correct spelling and punctuation Documentation/x86/boot: Fix typo x86/boot: Fix a comment's incorrect file reference x86/process: Remove set but not used variables prev and next x86/Kconfig: Fix Kconfig indentation
2020-01-10Merge branch 'x86/mm' into efi/core, to pick up dependenciesIngo Molnar1-1/+1
Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub: Use stricter typing for firmware function pointersArd Biesheuvel1-1/+1
We will soon remove another level of pointer casting, so let's make sure all type handling involving firmware calls at boot time is correct. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-10x86/Kconfig: Fix Kconfig indentationKrzysztof Kozlowski1-4/+4
Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ /\t/' -i */Kconfig Signed-off-by: Krzysztof Kozlowski <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Stefano Stabellini <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected]
2019-12-10x86/mm/pat: Rename <asm/pat.h> => <asm/memtype.h>Ingo Molnar1-1/+1
pat.h is a file whose main purpose is to provide the memtype_*() APIs. PAT is the low level hardware mechanism - but the high level abstraction is memtype. So name the header <memtype.h> as well - this goes hand in hand with memtype.c and memtype_interval.c. Signed-off-by: Ingo Molnar <[email protected]>
2019-11-26Merge branch 'x86-iopl-for-linus' of ↵Linus Torvalds1-10/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 iopl updates from Ingo Molnar: "This implements a nice simplification of the iopl and ioperm code that Thomas Gleixner discovered: we can implement the IO privilege features of the iopl system call by using the IO permission bitmap in permissive mode, while trapping CLI/STI/POPF/PUSHF uses in user-space if they change the interrupt flag. This implements that feature, with testing facilities and related cleanups" [ "Simplification" may be an over-statement. The main goal is to avoid the cli/sti of iopl by effectively implementing the IO port access parts of iopl in terms of ioperm. This may end up not workign well in case people actually depend on cli/sti being available, or if there are mixed uses of iopl and ioperm. We will see.. - Linus ] * 'x86-iopl-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86/ioperm: Fix use of deprecated config option x86/entry/32: Clarify register saving in __switch_to_asm() selftests/x86/iopl: Extend test to cover IOPL emulation x86/ioperm: Extend IOPL config to control ioperm() as well x86/iopl: Remove legacy IOPL option x86/iopl: Restrict iopl() permission scope x86/iopl: Fixup misleading comment selftests/x86/ioperm: Extend testing so the shared bitmap is exercised x86/ioperm: Share I/O bitmap if identical x86/ioperm: Remove bitmap if all permissions dropped x86/ioperm: Move TSS bitmap update to exit to user work x86/ioperm: Add bitmap sequence number x86/ioperm: Move iobitmap data into a struct x86/tss: Move I/O bitmap data into a seperate struct x86/io: Speedup schedule out of I/O bitmap user x86/ioperm: Avoid bitmap allocation if no permissions are set x86/ioperm: Simplify first ioperm() invocation logic x86/iopl: Cleanup include maze x86/tss: Fix and move VMX BUILD_BUG_ON() x86/cpu: Unify cpu_init() ...
2019-11-26Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds4-37/+40
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - Cross-arch changes to move the linker sections for NOTES and EXCEPTION_TABLE into the RO_DATA area, where they belong on most architectures. (Kees Cook) - Switch the x86 linker fill byte from x90 (NOP) to 0xcc (INT3), to trap jumps into the middle of those padding areas instead of sliding execution. (Kees Cook) - A thorough cleanup of symbol definitions within x86 assembler code. The rather randomly named macros got streamlined around a (hopefully) straightforward naming scheme: SYM_START(name, linkage, align...) SYM_END(name, sym_type) SYM_FUNC_START(name) SYM_FUNC_END(name) SYM_CODE_START(name) SYM_CODE_END(name) SYM_DATA_START(name) SYM_DATA_END(name) etc - with about three times of these basic primitives with some label, local symbol or attribute variant, expressed via postfixes. No change in functionality intended. (Jiri Slaby) - Misc other changes, cleanups and smaller fixes" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits) x86/entry/64: Remove pointless jump in paranoid_exit x86/entry/32: Remove unused resume_userspace label x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o m68k: Convert missed RODATA to RO_DATA x86/vmlinux: Use INT3 instead of NOP for linker fill bytes x86/mm: Report actual image regions in /proc/iomem x86/mm: Report which part of kernel image is freed x86/mm: Remove redundant address-of operators on addresses xtensa: Move EXCEPTION_TABLE to RO_DATA segment powerpc: Move EXCEPTION_TABLE to RO_DATA segment parisc: Move EXCEPTION_TABLE to RO_DATA segment microblaze: Move EXCEPTION_TABLE to RO_DATA segment ia64: Move EXCEPTION_TABLE to RO_DATA segment h8300: Move EXCEPTION_TABLE to RO_DATA segment c6x: Move EXCEPTION_TABLE to RO_DATA segment arm64: Move EXCEPTION_TABLE to RO_DATA segment alpha: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Actually use _etext for the end of the text segment vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA ...