From f2af7d25b4aa5b01203cc76e7530ea7fd18864a0 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Thu, 4 Jun 2015 14:18:49 +0800 Subject: x86/boot/setup: Clean up the e820_reserve_setup_data() code Deobfuscate the 'found' logic, it can be replaced with a simple: if (!pa_data) return; and 'found' can be eliminated. Signed-off-by: Wei Yang Cc: Andrew Morton Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Yinghai Lu Link: http://lkml.kernel.org/r/1433398729-8314-1-git-send-email-weiyang@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/setup.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d74ac33290ae..c3992c3a4378 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -461,19 +461,18 @@ static void __init e820_reserve_setup_data(void) { struct setup_data *data; u64 pa_data; - int found = 0; pa_data = boot_params.hdr.setup_data; + if (!pa_data) + return; + while (pa_data) { data = early_memremap(pa_data, sizeof(*data)); e820_update_range(pa_data, sizeof(*data)+data->len, E820_RAM, E820_RESERVED_KERN); - found = 1; pa_data = data->next; early_memunmap(data, sizeof(*data)); } - if (!found) - return; sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); memcpy(&e820_saved, &e820, sizeof(struct e820map)); -- cgit v1.2.3-70-g09d2 From db52ef74b35dcb91fd154fa52c618bdd1b90e28e Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 27 Jun 2015 10:25:14 +0200 Subject: x86/fpu: Fix FPU related boot regression when CPUID masking BIOS feature is enabled Mike Galbraith reported: " My i7-4790 box is having one hell of a time with this merge window, dead in the water. BIOS setting "Limit CPUID Maximum" upsets new fpu code mightily. " It turns out that Linux does a double workaround here, as per: 066941bd4eeb ("x86: unmask CPUID levels on Intel CPUs") it undoes the BIOS workaround - but as a side effect the CPUID state is not completely constant during early init anymore, and the new FPU init code did not take this into account. So what happened is that the xstate init code did not have full CPUID available, which broke subsequent attempts to use xstate features. Fix this by ordering the early FPU init code to after we've stabilized the CPUID state. Reported-bisected-and-tested-by: Mike Galbraith Cc: Andrew Morton Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20150627082514.GA10894@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 9fc5e3d9d9c8..922c5e0cea4c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -742,7 +742,6 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) cpu_detect(c); get_cpu_vendor(c); get_cpu_cap(c); - fpu__init_system(c); if (this_cpu->c_early_init) this_cpu->c_early_init(c); @@ -754,6 +753,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) this_cpu->c_bsp_init(c); setup_force_cpu_cap(X86_FEATURE_ALWAYS); + fpu__init_system(c); } void __init early_cpu_init(void) -- cgit v1.2.3-70-g09d2 From b96fecbfa8c88b057e2bbf10021521c232bb3650 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 4 Jul 2015 09:58:19 +0200 Subject: x86/fpu: Fix boot crash in the early FPU code Jan Kara and Thomas Gleixner reported boot crashes in the FPU code: general protection fault: 0000 [#1] SMP RIP: 0010:[] [] mxcsr_feature_mask_init+0x1c/0x40 2b:* 0f ae 85 00 fe ff ff fxsave -0x200(%rbp) and bisected it down to the following FPU commit: 91a8c2a5b43f ("x86/fpu: Clean up and fix MXCSR handling") The reason is that the on-stack FPU registers state variable, used by the FXSAVE instruction, did not have the required minimum alignment of 16 bytes, causing the general protection fault. This is most likely a GCC bug in older GCC versions, but the offending commit also added a bogus extra 32-byte alignment (which GCC ignored too). So fix this bug by making the variable static again, but also mark it __initdata this time, because fpu__init_system_mxcsr() is now an __init function. Reported-and-bisected-by: Jan Kara Reported-bisected-and-tested-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Jan Kara Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Quentin Casasnovas Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20150704075819.GA9201@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/init.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index fc878fee6a51..32826791e675 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -95,11 +95,12 @@ static void __init fpu__init_system_mxcsr(void) unsigned int mask = 0; if (cpu_has_fxsr) { - struct fxregs_state fx_tmp __aligned(32) = { }; + /* Static because GCC does not get 16-byte stack alignment right: */ + static struct fxregs_state fxregs __initdata; - asm volatile("fxsave %0" : "+m" (fx_tmp)); + asm volatile("fxsave %0" : "+m" (fxregs)); - mask = fx_tmp.mxcsr_mask; + mask = fxregs.mxcsr_mask; /* * If zero then use the default features mask, -- cgit v1.2.3-70-g09d2