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| author | Andy Lutomirski <luto@kernel.org> | 2016-09-29 21:48:12 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-09-30 12:40:12 +0200 |
| commit | 1ef55be16ed69538f89e0a6508be5e62fdc9851c (patch) | |
| tree | 623f3cb97a13b616e813aeadb46a56689d555141 /arch/x86/kernel | |
| parent | Merge branch 'x86/urgent' into x86/asm (diff) | |
| download | linux-1ef55be16ed69538f89e0a6508be5e62fdc9851c.tar.xz linux-1ef55be16ed69538f89e0a6508be5e62fdc9851c.zip | |
x86/asm: Get rid of __read_cr4_safe()
We use __read_cr4() vs __read_cr4_safe() inconsistently. On
CR4-less CPUs, all CR4 bits are effectively clear, so we can make
the code simpler and more robust by making __read_cr4() always fix
up faults on 32-bit kernels.
This may fix some bugs on old 486-like CPUs, but I don't have any
easy way to test that.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: david@saggiorato.net
Link: http://lkml.kernel.org/r/ea647033d357d9ce2ad2bbde5a631045f5052fb6.1475178370.git.luto@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/paravirt.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/process_32.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 2 |
3 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index bef340082d20..bbf3d5933eaa 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -332,7 +332,6 @@ __visible struct pv_cpu_ops pv_cpu_ops = { .read_cr0 = native_read_cr0, .write_cr0 = native_write_cr0, .read_cr4 = native_read_cr4, - .read_cr4_safe = native_read_cr4_safe, .write_cr4 = native_write_cr4, #ifdef CONFIG_X86_64 .read_cr8 = native_read_cr8, diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 404efdfa083b..bd7be8efdc4c 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -90,7 +90,7 @@ void __show_regs(struct pt_regs *regs, int all) cr0 = read_cr0(); cr2 = read_cr2(); cr3 = read_cr3(); - cr4 = __read_cr4_safe(); + cr4 = __read_cr4(); printk(KERN_DEFAULT "CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4); diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 87f2330cc805..3aabfdcbcb52 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1137,7 +1137,7 @@ void __init setup_arch(char **cmdline_p) * auditing all the early-boot CR4 manipulation would be needed to * rule it out. */ - mmu_cr4_features = __read_cr4_safe(); + mmu_cr4_features = __read_cr4(); memblock_set_current_limit(get_max_mapped()); |