x86/build: Treat R_386_PLT32 relocation as R_386_PC32

This is similar to commit

b21ebf2fb4cd ("x86: Treat R_X86_64_PLT32 as R_X86_64_PC32")

but for i386. As far as the kernel is concerned, R_386

x86/build: Treat R_386_PLT32 relocation as R_386_PC32

This is similar to commit

b21ebf2fb4cd ("x86: Treat R_X86_64_PLT32 as R_X86_64_PC32")

but for i386. As far as the kernel is concerned, R_386_PLT32 can be
treated the same as R_386_PC32.

R_386_PLT32/R_X86_64_PLT32 are PC-relative relocation types which
can only be used by branches. If the referenced symbol is defined
externally, a PLT will be used.

R_386_PC32/R_X86_64_PC32 are PC-relative relocation types which can be
used by address taking operations and branches. If the referenced symbol
is defined externally, a copy relocation/canonical PLT entry will be
created in the executable.

On x86-64, there is no PIC vs non-PIC PLT distinction and an
R_X86_64_PLT32 relocation is produced for both `call/jmp foo` and
`call/jmp foo@PLT` with newer (2018) GNU as/LLVM integrated assembler.
This avoids canonical PLT entries (st_shndx=0, st_value!=0).

On i386, there are 2 types of PLTs, PIC and non-PIC. Currently,
the GCC/GNU as convention is to use R_386_PC32 for non-PIC PLT and
R_386_PLT32 for PIC PLT. Copy relocations/canonical PLT entries
are possible ABI issues but GCC/GNU as will likely keep the status
quo because (1) the ABI is legacy (2) the change will drop a GNU
ld diagnostic for non-default visibility ifunc in shared objects.

clang-12 -fno-pic (since [1]) can emit R_386_PLT32 for compiler
generated function declarations, because preventing canonical PLT
entries is weighed over the rare ifunc diagnostic.

Further info for the more interested:

https://github.com/ClangBuiltLinux/linux/issues/1210
https://sourceware.org/bugzilla/show_bug.cgi?id=27169
https://github.com/llvm/llvm-project/commit/a084c0388e2a59b9556f2de0083333232da3f1d6 [1]

[ bp: Massage commit message. ]

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://lkml.kernel.org/r/20210127205600.1227437-1-maskray@google.com

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Merge branch 'next' into for-linus

Prepare second round of input updates for 5.3 merge window.

Merge tag 'v5.2' into next

Sync up with mainline to resolve conflicts in iforce driver.

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next-fixes

Some fixes have been accidentally pushed to this, so I cannot fost-forward.
Required to pull in the remove-fbcon-notifiers fixes.

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next-fixes

Some fixes have been accidentally pushed to this, so I cannot fost-forward.
Required to pull in the remove-fbcon-notifiers fixes.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux

Merge drm/drm-next into drm-intel-next-queued

Get the HDR dependencies originally merged via drm-misc. Sync up all
i915 changes applied via other trees. And get v5.2-rc2 as the baseline.

Signed-off

Merge drm/drm-next into drm-intel-next-queued

Get the HDR dependencies originally merged via drm-misc. Sync up all
i915 changes applied via other trees. And get v5.2-rc2 as the baseline.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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Merge drm/drm-next into drm-misc-next

Backmerging 5.2-rc1 to -misc-next for robher

Signed-off-by: Sean Paul <seanpaul@chromium.org>

Merge branch 'fixes-dra7' into fixes

Merge tag 'v5.2-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 5.2-rc1

Sync with upstream (which now contains fbdev-v5.2 changes) to
prepare a base

Merge tag 'v5.2-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 5.2-rc1

Sync with upstream (which now contains fbdev-v5.2 changes) to
prepare a base for fbdev-v5.3 changes.

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Merge tag 'v5.2-rc1' into spi-5.3

Linux 5.2-rc1

Merge tag 'v5.2-rc1' into regulator-5.3

Linux 5.2-rc1

Merge tag 'v5.2-rc1' into asoc-5.3

Linux 5.2-rc1

Merge branch 'linus' into core/urgent, to merge in dependent changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 irq updates from Ingo Molnar:
"Here are the main changes in this tree:

- Introduce x86-64 IRQ/

Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 irq updates from Ingo Molnar:
"Here are the main changes in this tree:

- Introduce x86-64 IRQ/exception/debug stack guard pages to detect
stack overflows immediately and deterministically.

- Clean up over a decade worth of cruft accumulated.

The outcome of this should be more clear-cut faults/crashes when any
of the low level x86 CPU stacks overflow, instead of silent memory
corruption and sporadic failures much later on"

* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
x86/irq: Fix outdated comments
x86/irq/64: Remove stack overflow debug code
x86/irq/64: Remap the IRQ stack with guard pages
x86/irq/64: Split the IRQ stack into its own pages
x86/irq/64: Init hardirq_stack_ptr during CPU hotplug
x86/irq/32: Handle irq stack allocation failure proper
x86/irq/32: Invoke irq_ctx_init() from init_IRQ()
x86/irq/64: Rename irq_stack_ptr to hardirq_stack_ptr
x86/irq/32: Rename hard/softirq_stack to hard/softirq_stack_ptr
x86/irq/32: Make irq stack a character array
x86/irq/32: Define IRQ_STACK_SIZE
x86/dumpstack/64: Speedup in_exception_stack()
x86/exceptions: Split debug IST stack
x86/exceptions: Enable IST guard pages
x86/exceptions: Disconnect IST index and stack order
x86/cpu: Remove orig_ist array
x86/cpu: Prepare TSS.IST setup for guard pages
x86/dumpstack/64: Use cpu_entry_area instead of orig_ist
x86/irq/64: Use cpu entry area instead of orig_ist
x86/traps: Use cpu_entry_area instead of orig_ist
...

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Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 build updates from Ingo Molnar:
"Misc updates:

- Add link flag quirk to solve LLVM linker bu

Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 build updates from Ingo Molnar:
"Misc updates:

- Add link flag quirk to solve LLVM linker bug that removes local
relocations, causing KASLR boot failures.

- Update the defconfigs to remove archaic partition table support

- Fix kernel growing pains: we had a bug in relocs.c handling section
header table entries count larger than 0xff00 (~65k), which can
happen with the -ffunction-sections flag, causing a build failure
with a cryptic error message. Add support for detecting the limit
and using the ELF protocol that extends the sections table via
->sh_size. The new limit is now much larger - over a billion
entries?"

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tools/relocs: Fix big section header tables
x86/defconfig: Remove archaic partition tables support
x86/build: Keep local relocations with ld.lld

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x86/tools/relocs: Fix big section header tables

In case when the number of entries in the section header table is larger
then or equal to SHN_LORESERVE the size of the table is held in the sh_size
m

x86/tools/relocs: Fix big section header tables

In case when the number of entries in the section header table is larger
then or equal to SHN_LORESERVE the size of the table is held in the sh_size
member of the initial entry in section header table instead of e_shnum.
Same with the string table index which is located in sh_link instead of
e_shstrndx.

This case is easily reproducible with KCFLAGS="-ffunction-sections",
bzImage build fails with "String table index out of bounds" error.

Signed-off-by: Artem Savkov <asavkov@redhat.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Eric W . Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181129155615.2594-1-asavkov@redhat.com
[ Simplify the die() lines. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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x86/irq/64: Split the IRQ stack into its own pages

Currently, the IRQ stack is hardcoded as the first page of the percpu
area, and the stack canary lives on the IRQ stack. The former gets in
the way

x86/irq/64: Split the IRQ stack into its own pages

Currently, the IRQ stack is hardcoded as the first page of the percpu
area, and the stack canary lives on the IRQ stack. The former gets in
the way of adding an IRQ stack guard page, and the latter is a potential
weakness in the stack canary mechanism.

Split the IRQ stack into its own private percpu pages.

[ tglx: Make 64 and 32 bit share struct irq_stack ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Feng Tang <feng.tang@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jordan Borgner <mail@jordan-borgner.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Maran Wilson <maran.wilson@oracle.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: "Rafael Ávila de Espíndola" <rafael@espindo.la>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20190414160146.267376656@linutronix.de

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Merge tag 'v4.20' into for-linus

Sync with mainline to get linux/overflow.h among other things.

Merge tag 'v4.20' into next

Merge with mainline to bring in the new APIs.

Merge branches 'for-4.20/upstream-fixes', 'for-4.21/core', 'for-4.21/hid-asus', 'for-4.21/hid-core', 'for-4.21/hid-cougar', 'for-4.21/hidraw', 'for-4.21/highres-wheel' and 'for-4.21/ish' into for-lin

Merge branches 'for-4.20/upstream-fixes', 'for-4.21/core', 'for-4.21/hid-asus', 'for-4.21/hid-core', 'for-4.21/hid-cougar', 'for-4.21/hidraw', 'for-4.21/highres-wheel' and 'for-4.21/ish' into for-linus

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Merge tag 'v4.20-rc7' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 4.20-rc7

Sync with upstream (which now contains fbdev-v4.20 changes) to
prepare a b

Merge tag 'v4.20-rc7' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 4.20-rc7

Sync with upstream (which now contains fbdev-v4.20 changes) to
prepare a base for fbdev-v4.21 changes.

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Merge tag 'v4.20-rc5' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge drm/drm-next into drm-intel-next-queued

Pull in v4.20-rc3 via drm-next.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

drm-next is forwarded to v4.20-rc1, and we need this to make
a patch series apply.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

drm-next is forwarded to v4.20-rc1, and we need this to make
a patch series apply.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

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Merge tag 'v4.20-rc2' into next-general

Sync to Linux 4.20-rc2 for downstream developers.