linux_dsm_epyc7002/arch/powerpc
Ariel Marcovitch 29c95dc43f powerpc: Fix alignment bug within the init sections
[ Upstream commit 2225a8dda263edc35a0e8b858fe2945cf6240fde ]

This is a bug that causes early crashes in builds with an .exit.text
section smaller than a page and an .init.text section that ends in the
beginning of a physical page (this is kinda random, which might
explain why this wasn't really encountered before).

The init sections are ordered like this:
  .init.text
  .exit.text
  .init.data

Currently, these sections aren't page aligned.

Because the init code might become read-only at runtime and because
the .init.text section can potentially reside on the same physical
page as .init.data, the beginning of .init.data might be mapped
read-only along with .init.text.

Then when the kernel tries to modify a variable in .init.data (like
kthreadd_done, used in kernel_init()) the kernel panics.

To avoid this, make _einittext page aligned and also align .exit.text
to make sure .init.data is always seperated from the text segments.

Fixes: 060ef9d89d ("powerpc32: PAGE_EXEC required for inittext")
Signed-off-by: Ariel Marcovitch <ariel.marcovitch@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210102201156.10805-1-ariel.marcovitch@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-27 11:55:07 +01:00
..
boot powerpc/boot: Fix build of dts/fsl 2020-12-30 11:54:01 +01:00
configs powerpc updates for 5.10 2020-10-16 12:21:15 -07:00
crypto crypto: powerpc/crc-vpmsum_test - Fix sparse endianness warning 2020-09-04 17:57:15 +10:00
include local64.h: make <asm/local64.h> mandatory 2021-01-12 20:18:16 +01:00
kernel powerpc: Fix alignment bug within the init sections 2021-01-27 11:55:07 +01:00
kexec arch, drivers: replace for_each_membock() with for_each_mem_range() 2020-10-13 18:38:35 -07:00
kvm KVM: PPC: Book3S HV: XIVE: Fix vCPU id sanity check 2020-12-01 21:45:51 +11:00
lib powerpc/sstep: Cover new VSX instructions under CONFIG_VSX 2020-12-30 11:53:47 +01:00
math-emu
mm powerpc/mm: Fix verification of MMU_FTR_TYPE_44x 2020-12-30 11:54:16 +01:00
net bpf, powerpc: Fix misuse of fallthrough in bpf_jit_comp() 2020-09-29 16:39:11 +02:00
oprofile powerpc/oprofile: fix spelling mistake "contex" -> "context" 2020-08-25 01:31:33 +10:00
perf powerpc/perf: Exclude kernel samples while counting events in user space. 2020-12-30 11:54:10 +01:00
platforms powerpc/64: irq replay remove decrementer overflow check 2021-01-06 14:56:54 +01:00
purgatory powerpc/kexec_file: Enable early kernel OPAL calls 2020-07-29 23:47:55 +10:00
sysdev powerpc: sysdev: add missing iounmap() on error in mpic_msgr_probe() 2021-01-06 14:56:53 +01:00
tools powerpc/tools: Remove 90 line limit in checkpatch script 2020-09-08 22:57:11 +10:00
xmon powerpc/xmon: Change printk() to pr_cont() 2020-12-30 11:54:16 +01:00
Kbuild powerpc/kexec: Move kexec files into a dedicated subdir. 2019-11-21 15:41:34 +11:00
Kconfig kbuild: Hoist '--orphan-handling' into Kconfig 2020-12-01 22:45:36 +09:00
Kconfig.debug powerpc: Remove Xilinx PPC405/PPC440 support 2020-05-28 23:24:34 +10:00
Makefile Kbuild fixes for v5.10 (2nd) 2020-12-06 10:31:39 -08:00
Makefile.postlink powerpc: unrel_branch_check.sh: use nm to find symbol value 2020-09-02 11:00:22 +10:00