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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-12-16 10:57:24 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-12-16 10:57:24 -0800 |
commit | a5e90b1b075f89f084047628d4ef181aded0bbfb (patch) | |
tree | da0010e547be7bf0f3b2bac9d7c74015e5e8662f /arch/arm/mm/context.c | |
parent | edb42dc7bc0da0125ceacab810a553ce1f0cac8d (diff) | |
parent | 34bfbae33ae84107d0c257edd6c6a8689a09be26 (diff) | |
download | linux-a5e90b1b075f89f084047628d4ef181aded0bbfb.tar.bz2 |
Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
"Further ARM fixes:
- Anson Huang noticed that we were corrupting a register we shouldn't
be during suspend on some CPUs.
- Shengjiu Wang spotted a bug in the 'swp' instruction emulation.
- Will Deacon fixed a bug in the ASID allocator.
- Laura Abbott fixed the kernel permission protection to apply to all
threads running in the system.
- I've fixed two bugs with the domain access control register
handling, one to do with printing an appropriate value at oops
time, and the other to further fix the uaccess_with_memcpy code"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8475/1: SWP emulation: Restore original *data when failed
ARM: 8471/1: need to save/restore arm register(r11) when it is corrupted
ARM: fix uaccess_with_memcpy() with SW_DOMAIN_PAN
ARM: report proper DACR value in oops dumps
ARM: 8464/1: Update all mm structures with section adjustments
ARM: 8465/1: mm: keep reserved ASIDs in sync with mm after multiple rollovers
Diffstat (limited to 'arch/arm/mm/context.c')
-rw-r--r-- | arch/arm/mm/context.c | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index 845769e41332..c8c8b9ed02e0 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -165,13 +165,28 @@ static void flush_context(unsigned int cpu) __flush_icache_all(); } -static int is_reserved_asid(u64 asid) +static bool check_update_reserved_asid(u64 asid, u64 newasid) { int cpu; - for_each_possible_cpu(cpu) - if (per_cpu(reserved_asids, cpu) == asid) - return 1; - return 0; + bool hit = false; + + /* + * Iterate over the set of reserved ASIDs looking for a match. + * If we find one, then we can update our mm to use newasid + * (i.e. the same ASID in the current generation) but we can't + * exit the loop early, since we need to ensure that all copies + * of the old ASID are updated to reflect the mm. Failure to do + * so could result in us missing the reserved ASID in a future + * generation. + */ + for_each_possible_cpu(cpu) { + if (per_cpu(reserved_asids, cpu) == asid) { + hit = true; + per_cpu(reserved_asids, cpu) = newasid; + } + } + + return hit; } static u64 new_context(struct mm_struct *mm, unsigned int cpu) @@ -181,12 +196,14 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) u64 generation = atomic64_read(&asid_generation); if (asid != 0) { + u64 newasid = generation | (asid & ~ASID_MASK); + /* * If our current ASID was active during a rollover, we * can continue to use it and this was just a false alarm. */ - if (is_reserved_asid(asid)) - return generation | (asid & ~ASID_MASK); + if (check_update_reserved_asid(asid, newasid)) + return newasid; /* * We had a valid ASID in a previous life, so try to re-use @@ -194,7 +211,7 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) */ asid &= ~ASID_MASK; if (!__test_and_set_bit(asid, asid_map)) - goto bump_gen; + return newasid; } /* @@ -216,11 +233,8 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) __set_bit(asid, asid_map); cur_idx = asid; - -bump_gen: - asid |= generation; cpumask_clear(mm_cpumask(mm)); - return asid; + return asid | generation; } void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk) |