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Revert "arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption" 

This reverts commit 44ecda71fd.

All versions of this patch on the mailing list, including the version
that ended up getting merged, have portions of code guarded by the
non-existent CONFIG_ARM64_WORKAROUND_2645198 option. Although Anshuman
says he tested the code with some additional debug changes [1], I'm
hesitant to fix the CONFIG option and light up a bunch of code right
before I (and others) disappear for the end of year holidays, during
which time we won't be around to deal with any fallout.

So revert the change for now. We can bring back a fixed, tested version
for a later -rc when folks are thinking about things other than trees
and turkeys.

[1] https://lore.kernel.org/r/b6f61241-e436-5db1-1053-3b441080b8d6@arm.com
Reported-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20221215094811.23188-1-lukas.bulwahn@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Will Deacon 2022-12-15 17:59:12 +00:00
parent 38792972de
commit c0cd1d5417
8 changed files with 0 additions and 86 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/arm64/silicon-errata.rst
View File

@ -120,8 +120,6 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A710 | #2224489 | ARM64_ERRATUM_2224489 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A715 | #2645198 | ARM64_ERRATUM_2645198 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-X2 | #2119858 | ARM64_ERRATUM_2119858 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-X2 | #2224489 | ARM64_ERRATUM_2224489 |

16
arch/arm64/Kconfig
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@ -971,22 +971,6 @@ config ARM64_ERRATUM_2457168
If unsure, say Y.
config ARM64_ERRATUM_2645198
bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
default y
help
This option adds the workaround for ARM Cortex-A715 erratum 2645198.
If a Cortex-A715 cpu sees a page mapping permissions change from executable
to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
next instruction abort caused by permission fault.
Only user-space does executable to non-executable permission transition via
mprotect() system call. Workaround the problem by doing a break-before-make
TLB invalidation, for all changes to executable user space mappings.
If unsure, say Y.
config CAVIUM_ERRATUM_22375
bool "Cavium erratum 22375, 24313"
default y

9
arch/arm64/include/asm/hugetlb.h
View File

@ -49,15 +49,6 @@ extern pte_t huge_ptep_get(pte_t *ptep);
void __init arm64_hugetlb_cma_reserve(void);
#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep);
#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t old_pte, pte_t new_pte);
#include <asm-generic/hugetlb.h>
#endif /* __ASM_HUGETLB_H */

9
arch/arm64/include/asm/pgtable.h
View File

@ -1095,15 +1095,6 @@ static inline bool pud_sect_supported(void)
}
#define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
#define ptep_modify_prot_start ptep_modify_prot_start
extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep);
#define ptep_modify_prot_commit ptep_modify_prot_commit
extern void ptep_modify_prot_commit(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t old_pte, pte_t new_pte);
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_PGTABLE_H */

7
arch/arm64/kernel/cpu_errata.c
View File

@ -661,13 +661,6 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
CAP_MIDR_RANGE_LIST(trbe_write_out_of_range_cpus),
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_2645198
{
.desc = "ARM erratum 2645198",
.capability = ARM64_WORKAROUND_2645198,
ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A715)
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_2077057
{
.desc = "ARM erratum 2077057",

21
arch/arm64/mm/hugetlbpage.c
View File

@ -559,24 +559,3 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
{
return __hugetlb_valid_size(size);
}
pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198) &&
cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
/*
* Break-before-make (BBM) is required for all user space mappings
* when the permission changes from executable to non-executable
* in cases where cpu is affected with errata #2645198.
*/
if (pte_user_exec(READ_ONCE(*ptep)))
return huge_ptep_clear_flush(vma, addr, ptep);
}
return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
}
void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
pte_t old_pte, pte_t pte)
{
set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
}

21
arch/arm64/mm/mmu.c
View File

@ -1702,24 +1702,3 @@ static int __init prevent_bootmem_remove_init(void)
}
early_initcall(prevent_bootmem_remove_init);
#endif
pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198) &&
cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
/*
* Break-before-make (BBM) is required for all user space mappings
* when the permission changes from executable to non-executable
* in cases where cpu is affected with errata #2645198.
*/
if (pte_user_exec(READ_ONCE(*ptep)))
return ptep_clear_flush(vma, addr, ptep);
}
return ptep_get_and_clear(vma->vm_mm, addr, ptep);
}
void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
pte_t old_pte, pte_t pte)
{
set_pte_at(vma->vm_mm, addr, ptep, pte);
}

1
arch/arm64/tools/cpucaps
View File

@ -71,7 +71,6 @@ WORKAROUND_2038923
WORKAROUND_2064142
WORKAROUND_2077057
WORKAROUND_2457168
WORKAROUND_2645198
WORKAROUND_2658417
WORKAROUND_TRBE_OVERWRITE_FILL_MODE
WORKAROUND_TSB_FLUSH_FAILURE