From 956421fbb74c3a6261903f3836c0740187cf038b Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 5 Mar 2015 01:09:44 +0100 Subject: x86/asm/entry/64: Remove a bogus 'ret_from_fork' optimization 'ret_from_fork' checks TIF_IA32 to determine whether 'pt_regs' and the related state make sense for 'ret_from_sys_call'. This is entirely the wrong check. TS_COMPAT would make a little more sense, but there's really no point in keeping this optimization at all. This fixes a return to the wrong user CS if we came from int 0x80 in a 64-bit task. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Thomas Gleixner Cc: Link: http://lkml.kernel.org/r/4710be56d76ef994ddf59087aad98c000fbab9a4.1424989793.git.luto@amacapital.net [ Backported from tip:x86/asm. ] Signed-off-by: Ingo Molnar --- arch/x86/kernel/entry_64.S | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 10074ad9ebf..1d74d161687 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -269,11 +269,14 @@ ENTRY(ret_from_fork) testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? jz 1f - testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET - jnz int_ret_from_sys_call - - RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET - jmp ret_from_sys_call # go to the SYSRET fastpath + /* + * By the time we get here, we have no idea whether our pt_regs, + * ti flags, and ti status came from the 64-bit SYSCALL fast path, + * the slow path, or one of the ia32entry paths. + * Use int_ret_from_sys_call to return, since it can safely handle + * all of the above. + */ + jmp int_ret_from_sys_call 1: subq $REST_SKIP, %rsp # leave space for volatiles -- cgit v1.2.3-70-g09d2 From 9ab6eb51ef4ad63cb71533d3a4dfb09ea8f69b4c Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 5 Mar 2015 17:24:04 +0200 Subject: x86/intel/quark: Select COMMON_CLK The commit 8bbc2a135b63 ("x86/intel/quark: Add Intel Quark platform support") introduced a minimal support of Intel Quark SoC. That allows to use core parts of the SoC. However, the SPI, I2C, and GPIO drivers can't be selected by kernel configuration because they depend on COMMON_CLK. The patch adds a COMMON_CLK selection to the platfrom definition to allow user choose the drivers. Signed-off-by: Andy Shevchenko Acked-by: Ong, Boon Leong Cc: Bryan O'Donoghue Cc: Darren Hart Fixes: 8bbc2a135b63 ("x86/intel/quark: Add Intel Quark platform support") Link: http://lkml.kernel.org/r/1425569044-2867-1-git-send-email-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c2fb8a87dcc..b7d31ca5518 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -499,6 +499,7 @@ config X86_INTEL_QUARK depends on X86_IO_APIC select IOSF_MBI select INTEL_IMR + select COMMON_CLK ---help--- Select to include support for Quark X1000 SoC. Say Y here if you have a Quark based system such as the Arduino -- cgit v1.2.3-70-g09d2 From 06c8173eb92bbfc03a0fe8bb64315857d0badd06 Mon Sep 17 00:00:00 2001 From: Quentin Casasnovas Date: Thu, 5 Mar 2015 13:19:22 +0100 Subject: x86/fpu/xsaves: Fix improper uses of __ex_table Commit: f31a9f7c7169 ("x86/xsaves: Use xsaves/xrstors to save and restore xsave area") introduced alternative instructions for XSAVES/XRSTORS and commit: adb9d526e982 ("x86/xsaves: Add xsaves and xrstors support for booting time") added support for the XSAVES/XRSTORS instructions at boot time. Unfortunately both failed to properly protect them against faulting: The 'xstate_fault' macro will use the closest label named '1' backward and that ends up in the .altinstr_replacement section rather than in .text. This means that the kernel will never find in the __ex_table the .text address where this instruction might fault, leading to serious problems if userspace manages to trigger the fault. Signed-off-by: Quentin Casasnovas Signed-off-by: Jamie Iles [ Improved the changelog, fixed some whitespace noise. ] Acked-by: Borislav Petkov Acked-by: Linus Torvalds Cc: Cc: Allan Xavier Cc: H. Peter Anvin Cc: Thomas Gleixner Fixes: adb9d526e982 ("x86/xsaves: Add xsaves and xrstors support for booting time") Fixes: f31a9f7c7169 ("x86/xsaves: Use xsaves/xrstors to save and restore xsave area") Signed-off-by: Ingo Molnar --- arch/x86/include/asm/xsave.h | 28 +++++++++++----------------- 1 file changed, 11 insertions(+), 17 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h index 5fa9770035d..c9a6d68b8d6 100644 --- a/arch/x86/include/asm/xsave.h +++ b/arch/x86/include/asm/xsave.h @@ -82,18 +82,15 @@ static inline int xsave_state_booting(struct xsave_struct *fx, u64 mask) if (boot_cpu_has(X86_FEATURE_XSAVES)) asm volatile("1:"XSAVES"\n\t" "2:\n\t" - : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + xstate_fault + : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) : "memory"); else asm volatile("1:"XSAVE"\n\t" "2:\n\t" - : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + xstate_fault + : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) : "memory"); - - asm volatile(xstate_fault - : "0" (0) - : "memory"); - return err; } @@ -112,18 +109,15 @@ static inline int xrstor_state_booting(struct xsave_struct *fx, u64 mask) if (boot_cpu_has(X86_FEATURE_XSAVES)) asm volatile("1:"XRSTORS"\n\t" "2:\n\t" - : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + xstate_fault + : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) : "memory"); else asm volatile("1:"XRSTOR"\n\t" "2:\n\t" - : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) + xstate_fault + : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) : "memory"); - - asm volatile(xstate_fault - : "0" (0) - : "memory"); - return err; } @@ -149,9 +143,9 @@ static inline int xsave_state(struct xsave_struct *fx, u64 mask) */ alternative_input_2( "1:"XSAVE, - "1:"XSAVEOPT, + XSAVEOPT, X86_FEATURE_XSAVEOPT, - "1:"XSAVES, + XSAVES, X86_FEATURE_XSAVES, [fx] "D" (fx), "a" (lmask), "d" (hmask) : "memory"); @@ -178,7 +172,7 @@ static inline int xrstor_state(struct xsave_struct *fx, u64 mask) */ alternative_input( "1: " XRSTOR, - "1: " XRSTORS, + XRSTORS, X86_FEATURE_XSAVES, "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask) : "memory"); -- cgit v1.2.3-70-g09d2