From 42854dc0a6320ff36722749acafa0697522d9556 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 16 Mar 2009 17:24:34 -0700 Subject: x86, paravirt: prevent gcc from generating the wrong addressing mode Impact: fix crash on VMI (VMware) When we generate a call sequence for calling a paravirtualized function, we presume that the generated code is "call *0xXXXXX", which is a 6 byte opcode; this is larger than a normal direct call, and so we can patch a direct call over it. At the moment, however we give gcc enough rope to hang us by putting the address in a register and generating a two byte indirect-via-register call. Prevent this by explicitly dereferencing the function pointer and passing it into the asm as a constant. This prevents crashes in VMI, as it cannot handle unpatchable callsites. Signed-off-by: Jeremy Fitzhardinge Cc: Alok Kataria LKML-Reference: <49BEEDC2.2070809@goop.org> Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/paravirt.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/include/asm/paravirt.h') diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index e299287e8e3..0c212d528c0 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -360,7 +360,7 @@ extern struct pv_lock_ops pv_lock_ops; #define paravirt_type(op) \ [paravirt_typenum] "i" (PARAVIRT_PATCH(op)), \ - [paravirt_opptr] "m" (op) + [paravirt_opptr] "i" (&(op)) #define paravirt_clobber(clobber) \ [paravirt_clobber] "i" (clobber) @@ -412,7 +412,7 @@ int paravirt_disable_iospace(void); * offset into the paravirt_patch_template structure, and can therefore be * freely converted back into a structure offset. */ -#define PARAVIRT_CALL "call *%[paravirt_opptr];" +#define PARAVIRT_CALL "call *%c[paravirt_opptr];" /* * These macros are intended to wrap calls through one of the paravirt -- cgit v1.2.3-18-g5258 From 71ff49d71bb5cfcd2689b54cb433c0e6990a1d86 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 18 Mar 2009 13:03:33 -0700 Subject: x86: with the last user gone, remove set_pte_present Impact: cleanup set_pte_present() is no longer used, directly or indirectly, so remove it. Signed-off-by: Jeremy Fitzhardinge Cc: Xen-devel Cc: Jeremy Fitzhardinge Cc: Alok Kataria Cc: Marcelo Tosatti Cc: Avi Kivity LKML-Reference: <1237406613-2929-2-git-send-email-jeremy@goop.org> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/paravirt.h | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'arch/x86/include/asm/paravirt.h') diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 31fe83b10a4..7727aa8b7dd 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -317,8 +317,6 @@ struct pv_mmu_ops { #if PAGETABLE_LEVELS >= 3 #ifdef CONFIG_X86_PAE void (*set_pte_atomic)(pte_t *ptep, pte_t pteval); - void (*set_pte_present)(struct mm_struct *mm, unsigned long addr, - pte_t *ptep, pte_t pte); void (*pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep); void (*pmd_clear)(pmd_t *pmdp); @@ -1365,13 +1363,6 @@ static inline void set_pte_atomic(pte_t *ptep, pte_t pte) pte.pte, pte.pte >> 32); } -static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, - pte_t *ptep, pte_t pte) -{ - /* 5 arg words */ - pv_mmu_ops.set_pte_present(mm, addr, ptep, pte); -} - static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { @@ -1388,12 +1379,6 @@ static inline void set_pte_atomic(pte_t *ptep, pte_t pte) set_pte(ptep, pte); } -static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, - pte_t *ptep, pte_t pte) -{ - set_pte(ptep, pte); -} - static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { -- cgit v1.2.3-18-g5258