search for: __jump_table

...e asm constraint 'i'" in arch/x86/include/asm/jump_table.h. The source code is static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("1:" ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" ".pushsection __jump_table, \"aw\" \n\t" _ASM_ALIGN "\n\t" ".long 1b - ., %l[l_yes] - . \n\t" _ASM_PTR "%c0 + %c1 - .\n\t" ".popsection \n\t" : : "i" (key), "i" (branch) : : l_yes); return false; l_yes: return true; } The error pointed to asm_vola...

...OP -.Lstatic_branch_no_after_\@: +.macro STATIC_JUMP_IF_TRUE target, key, def +.Lstatic_jump_\@: + .if \def + /* Equivalent to "jmp.d32 \target" */ + .byte 0xe9 + .long \target - .Lstatic_jump_after_\@ +.Lstatic_jump_after_\@: + .else + .byte STATIC_KEY_INIT_NOP + .endif .pushsection __jump_table, "aw" _ASM_ALIGN - .long .Lstatic_branch_nop_\@ - ., \l_yes - . - _ASM_PTR \key + \branch - . + .long .Lstatic_jump_\@ - ., \target - . + _ASM_PTR \key - . .popsection .endm -.macro STATIC_BRANCH_JMP l_yes:req key:req branch:req -.Lstatic_branch_jmp_\@: - .byte 0xe9 - .lon...

...Section (__DATA, __bss): 65 Section (__TEXT, __textcoal_nt): 116324 | Section (__TEXT, __textcoal_nt): 168920 Section (__TEXT, __literal8): 8 | Section (__TEXT, __eh_frame): 88636 Section (__TEXT, __StaticInit): 147 | Section (__TEXT, __StaticInit): 166 Section (__IMPORT, __jump_table): 12790 | Section (__IMPORT, __jump_table): 12410 Section (__IMPORT, __pointers): 136 | Section (__IMPORT, __pointers): 128 total 1495929 | total 2211546 total 1495968 | total 2211617 There are several problems here: 1. We're emitting __eh_frame even though it...

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

...NOP l_yes=\"%l[l_yes]\" key=\"%c0\" " - "branch=\"%c1\"" - : : "i" (key), "i" (branch) : : l_yes); + asm_volatile_goto("1:" + ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" + ".pushsection __jump_table, \"aw\" \n\t" + _ASM_ALIGN "\n\t" + ".long 1b - ., %l[l_yes] - . \n\t" + _ASM_PTR "%c0 + %c1 - .\n\t" + ".popsection \n\t" + : : "i" (key), "i" (branch) : : l_yes); + return false; l_yes: return true; @@ -30,8 +4...

...NOP l_yes=\"%l[l_yes]\" key=\"%c0\" " - "branch=\"%c1\"" - : : "i" (key), "i" (branch) : : l_yes); + asm_volatile_goto("1:" + ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" + ".pushsection __jump_table, \"aw\" \n\t" + _ASM_ALIGN "\n\t" + ".long 1b - ., %l[l_yes] - . \n\t" + _ASM_PTR "%c0 + %c1 - .\n\t" + ".popsection \n\t" + : : "i" (key), "i" (branch) : : l_yes); + return false; l_yes: return true; @@ -30,8 +4...

...NOP l_yes=\"%l[l_yes]\" key=\"%c0\" " - "branch=\"%c1\"" - : : "i" (key), "i" (branch) : : l_yes); + asm_volatile_goto("1:" + ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" + ".pushsection __jump_table, \"aw\" \n\t" + _ASM_ALIGN "\n\t" + ".long 1b - ., %l[l_yes] - . \n\t" + _ASM_PTR "%c0 + %c1 - .\n\t" + ".popsection \n\t" + : : "i" (key), "i" (branch) : : l_yes); + return false; l_yes: return true; @@ -30,8 +3...

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

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