search for: asm_call_constraint

...PVOP_TEST_NULL(op); \ - /* This is 32-bit specific, but is okay in 64-bit */ \ - /* since this condition will never hold */ \ - if (sizeof(rettype) > sizeof(unsigned long)) { \ - asm volatile(pre \ - paravirt_alt(PARAVIRT_CALL) \ - post \ - : call_clbr, ASM_CALL_CONSTRAINT \ - : paravirt_type(op), \ - paravirt_clobber(clbr), \ - ##__VA_ARGS__ \ - : "memory", "cc" extra_clbr); \ - __ret = (rettype)((((u64)__edx) << 32) | __eax); \ - } else { \ - asm volatile(pre \ - paravirt_alt(PAR...

.... @@ -509,7 +531,7 @@ int paravirt_disable_iospace(void); /* since this condition will never hold */ \ if (sizeof(rettype) > sizeof(unsigned long)) { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : call_clbr, ASM_CALL_CONSTRAINT \ : paravirt_type(op), \ @@ -519,7 +541,7 @@ int paravirt_disable_iospace(void); __ret = (rettype)((((u64)__edx) << 32) | __eax); \ } else { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : c...

...; \ - PVOP_CALL_ARGS; \ - PVOP_TEST_NULL(op); \ +({ \ + rettype __ret; \ + PVOP_CALL_ARGS; \ + PVOP_TEST_NULL(op); \ asm volatile(pre \ - paravirt_alt(PARAVIRT_CALL) \ + PV_SITE(PV_CALL_STR) \ post \ : call_clbr, ASM_CALL_CONSTRAINT \ - : paravirt_type(op), \ - paravirt_clobber(clbr), \ + : PV_INPUT_CONSTRAINTS(op, clbr), \ ##__VA_ARGS__ \ : "memory", "cc" extra_clbr); \ - if (IS_ENABLED(CONFIG_X86_32) && \ - sizeof(rettype) > sizeof(un...

This changes the pv ops code generation to more closely match reality. For example, instead of: callq *0xffffffff81e3a400 (pv_irq_ops.save_fl) vmlinux will now show: pushfq pop %rax nop nop nop nop nop which is what the runtime version of the code will show in most cases. This idea was suggested by Andy Lutomirski. The benefits are: - For the most common runtime cases

This changes the pv ops code generation to more closely match reality. For example, instead of: callq *0xffffffff81e3a400 (pv_irq_ops.save_fl) vmlinux will now show: pushfq pop %rax nop nop nop nop nop which is what the runtime version of the code will show in most cases. This idea was suggested by Andy Lutomirski. The benefits are: - For the most common runtime cases

This series reverts the in-kernel workarounds for inlining issues. The commit description of 77b0bf55bc67 mentioned "We also hope that GCC will eventually get fixed,..." Now, GCC provides a solution. https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html explains the new "asm inline" syntax. The performance issue will be eventually solved. [About Code cleanups] I know Nadam

This series reverts the in-kernel workarounds for inlining issues. The commit description of 77b0bf55bc67 mentioned "We also hope that GCC will eventually get fixed,..." Now, GCC provides a solution. https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html explains the new "asm inline" syntax. The performance issue will be eventually solved. [About Code cleanups] I know Nadam

.... @@ -509,7 +531,7 @@ int paravirt_disable_iospace(void); /* since this condition will never hold */ \ if (sizeof(rettype) > sizeof(unsigned long)) { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : call_clbr, ASM_CALL_CONSTRAINT \ : paravirt_type(op), \ @@ -519,7 +541,7 @@ int paravirt_disable_iospace(void); __ret = (rettype)((((u64)__edx) << 32) | __eax); \ } else { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : c...

...pre, post, ##__VA_ARGS__) +#define ____PVOP_ALT_CALL(rettype, native, op, clbr, call_clbr, \ + extra_clbr, ...) \ +({ \ + rettype __ret; \ + PVOP_CALL_ARGS; \ + PVOP_TEST_NULL(op); \ + asm volatile(PV_ALT_SITE(native, PV_CALL_STR) \ + : call_clbr, ASM_CALL_CONSTRAINT \ + : PV_INPUT_CONSTRAINTS(op, clbr), \ + ##__VA_ARGS__ \ + : "memory", "cc" extra_clbr); \ + if (IS_ENABLED(CONFIG_X86_32) && \ + sizeof(rettype) > sizeof(unsigned long)) \ + __ret = (rettype)((((u64)__edx) << 32) | __eax...

.... @@ -509,7 +531,7 @@ int paravirt_disable_iospace(void); /* since this condition will never hold */ \ if (sizeof(rettype) > sizeof(unsigned long)) { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : call_clbr, ASM_CALL_CONSTRAINT \ : paravirt_type(op), \ @@ -519,7 +541,7 @@ int paravirt_disable_iospace(void); __ret = (rettype)((((u64)__edx) << 32) | __eax); \ } else { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : c...

.... @@ -509,7 +531,7 @@ int paravirt_disable_iospace(void); /* since this condition will never hold */ \ if (sizeof(rettype) > sizeof(unsigned long)) { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : call_clbr, ASM_CALL_CONSTRAINT \ : paravirt_type(op), \ @@ -519,7 +541,7 @@ int paravirt_disable_iospace(void); __ret = (rettype)((((u64)__edx) << 32) | __eax); \ } else { \ asm volatile(pre \ - paravirt_call \ + paravirt_alt(PARAVIRT_CALL) \ post \ : c...

This is a small series getting rid of paravirt patching by switching completely to alternative patching for the same functionality. The basic idea is to add the capability to switch from indirect to direct calls via a special alternative patching option. This removes _some_ of the paravirt macro maze, but most of it needs to stay due to the need of hiding the call instructions from the compiler

This is a small series getting rid of paravirt patching by switching completely to alternative patching for the same functionality. The basic idea is to add the capability to switch from indirect to direct calls via a special alternative patching option. This removes _some_ of the paravirt macro maze, but most of it needs to stay due to the need of hiding the call instructions from the compiler

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to

Changes: - patch v3: - Update on message to describe longer term PIE goal. - Minor change on ftrace if condition. - Changed code using xchgq. - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace

Changes: - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce dynamic relocation space on mapped memory. It also simplifies the relocation process. - Move the start the module section next to the kernel. Remove the need for -mcmodel=large on modules. Extends

Changes: - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce dynamic relocation space on mapped memory. It also simplifies the relocation process. - Move the start the module section next to the kernel. Remove the need for -mcmodel=large on modules. Extends