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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-24 11:03:26 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-24 11:03:26 -0700 |
commit | 0a72ef89901409847036664c23ba6eee7cf08e0e (patch) | |
tree | bb20f0011292a0e1abb4326a1387c4649313aac9 /arch/arm64/kernel/syscall.c | |
parent | Merge tag 'platform-drivers-x86-v5.2-2' of git://git.infradead.org/linux-platform-drivers-x86 (diff) | |
parent | arm64: insn: Add BUILD_BUG_ON() for invalid masks (diff) | |
download | linux-dev-0a72ef89901409847036664c23ba6eee7cf08e0e.tar.xz linux-dev-0a72ef89901409847036664c23ba6eee7cf08e0e.zip |
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull more arm64 fixes from Will Deacon:
- Fix incorrect LDADD instruction encoding in our disassembly macros
- Disable the broken ARM64_PSEUDO_NMI support for now
- Add workaround for Cortex-A76 CPU erratum #1463225
- Handle Cortex-A76/Neoverse-N1 erratum #1418040 w/ existing workaround
- Fix IORT build failure if IOMMU_SUPPORT=n
- Fix place-relative module relocation range checking and its
interaction with KASLR
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: insn: Add BUILD_BUG_ON() for invalid masks
arm64: insn: Fix ldadd instruction encoding
arm64: Kconfig: Make ARM64_PSEUDO_NMI depend on BROKEN for now
arm64: Handle erratum 1418040 as a superset of erratum 1188873
arm64/module: deal with ambiguity in PRELxx relocation ranges
ACPI/IORT: Fix build error when IOMMU_SUPPORT is disabled
arm64/kernel: kaslr: reduce module randomization range to 2 GB
arm64: errata: Add workaround for Cortex-A76 erratum #1463225
arm64: Remove useless message during oops
Diffstat (limited to 'arch/arm64/kernel/syscall.c')
-rw-r--r-- | arch/arm64/kernel/syscall.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index 5610ac01c1ec..871c739f060a 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -8,6 +8,7 @@ #include <linux/syscalls.h> #include <asm/daifflags.h> +#include <asm/debug-monitors.h> #include <asm/fpsimd.h> #include <asm/syscall.h> #include <asm/thread_info.h> @@ -60,6 +61,35 @@ static inline bool has_syscall_work(unsigned long flags) int syscall_trace_enter(struct pt_regs *regs); void syscall_trace_exit(struct pt_regs *regs); +#ifdef CONFIG_ARM64_ERRATUM_1463225 +DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa); + +static void cortex_a76_erratum_1463225_svc_handler(void) +{ + u32 reg, val; + + if (!unlikely(test_thread_flag(TIF_SINGLESTEP))) + return; + + if (!unlikely(this_cpu_has_cap(ARM64_WORKAROUND_1463225))) + return; + + __this_cpu_write(__in_cortex_a76_erratum_1463225_wa, 1); + reg = read_sysreg(mdscr_el1); + val = reg | DBG_MDSCR_SS | DBG_MDSCR_KDE; + write_sysreg(val, mdscr_el1); + asm volatile("msr daifclr, #8"); + isb(); + + /* We will have taken a single-step exception by this point */ + + write_sysreg(reg, mdscr_el1); + __this_cpu_write(__in_cortex_a76_erratum_1463225_wa, 0); +} +#else +static void cortex_a76_erratum_1463225_svc_handler(void) { } +#endif /* CONFIG_ARM64_ERRATUM_1463225 */ + static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, const syscall_fn_t syscall_table[]) { @@ -68,6 +98,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, regs->orig_x0 = regs->regs[0]; regs->syscallno = scno; + cortex_a76_erratum_1463225_svc_handler(); local_daif_restore(DAIF_PROCCTX); user_exit(); |