pkubaj commented on code in PR #3696: URL: https://github.com/apache/brpc/pull/3696#discussion_r4440484605
########## src/bthread/context.cpp: ########## @@ -1012,3 +1012,247 @@ __asm ( " call _exit\n" ); #endif + +#if defined(BTHREAD_CONTEXT_PLATFORM_linux_ppc64) && defined(BTHREAD_CONTEXT_COMPILER_gcc) +__asm ( +".text\n" +".align 2\n" +".globl bthread_jump_fcontext\n" +".type bthread_jump_fcontext, @function\n" +"bthread_jump_fcontext:\n" +" addis %r2, %r12, .TOC.-bthread_jump_fcontext@ha\n" +" addi %r2, %r2, .TOC.-bthread_jump_fcontext@l\n" +" .localentry bthread_jump_fcontext, . - bthread_jump_fcontext\n" +" # reserve space on stack\n" +" subi %r1, %r1, 528\n" +" std %r14, 352(%r1)\n" +" std %r15, 360(%r1)\n" +" std %r16, 368(%r1)\n" +" std %r17, 376(%r1)\n" +" std %r18, 384(%r1)\n" +" std %r19, 392(%r1)\n" +" std %r20, 400(%r1)\n" +" std %r21, 408(%r1)\n" +" std %r22, 416(%r1)\n" +" std %r23, 424(%r1)\n" +" std %r24, 432(%r1)\n" +" std %r25, 440(%r1)\n" +" std %r26, 448(%r1)\n" +" std %r27, 456(%r1)\n" +" std %r28, 464(%r1)\n" +" std %r29, 472(%r1)\n" +" std %r30, 480(%r1)\n" +" std %r31, 488(%r1)\n" +" # save CR\n" +" mfcr %r0\n" +" std %r0, 496(%r1)\n" +" # save LR, and LR as PC\n" +" mflr %r0\n" +" std %r0, 504(%r1)\n" +" std %r0, 512(%r1)\n" +" # the fourth argument (preserve_fpu) is ignored: the compiler may keep\n" +" # any value in the non-volatile FPRs/VRs across the call\n" +" stfd %f14, 200(%r1)\n" +" stfd %f15, 208(%r1)\n" +" stfd %f16, 216(%r1)\n" +" stfd %f17, 224(%r1)\n" +" stfd %f18, 232(%r1)\n" +" stfd %f19, 240(%r1)\n" +" stfd %f20, 248(%r1)\n" +" stfd %f21, 256(%r1)\n" +" stfd %f22, 264(%r1)\n" +" stfd %f23, 272(%r1)\n" +" stfd %f24, 280(%r1)\n" +" stfd %f25, 288(%r1)\n" +" stfd %f26, 296(%r1)\n" +" stfd %f27, 304(%r1)\n" +" stfd %f28, 312(%r1)\n" +" stfd %f29, 320(%r1)\n" +" stfd %f30, 328(%r1)\n" +" stfd %f31, 336(%r1)\n" +" mffs %f0\n" +" stfd %f0, 344(%r1)\n" +#ifdef __ALTIVEC__ +" mfspr %r0, 256\n" +" std %r0, 192(%r1)\n" +" li %r11, 0\n" +" stvx %v20, %r1, %r11\n" +" li %r11, 16\n" +" stvx %v21, %r1, %r11\n" +" li %r11, 32\n" +" stvx %v22, %r1, %r11\n" +" li %r11, 48\n" +" stvx %v23, %r1, %r11\n" +" li %r11, 64\n" +" stvx %v24, %r1, %r11\n" +" li %r11, 80\n" +" stvx %v25, %r1, %r11\n" +" li %r11, 96\n" +" stvx %v26, %r1, %r11\n" +" li %r11, 112\n" +" stvx %v27, %r1, %r11\n" +" li %r11, 128\n" +" stvx %v28, %r1, %r11\n" +" li %r11, 144\n" +" stvx %v29, %r1, %r11\n" +" li %r11, 160\n" +" stvx %v30, %r1, %r11\n" +" li %r11, 176\n" +" stvx %v31, %r1, %r11\n" +#endif +" # store RSP (pointing to context-data) in R3\n" +" std %r1, 0(%r3)\n" +" # restore RSP (pointing to context-data) from R4\n" +" mr %r1, %r4\n" +#ifdef __ALTIVEC__ +" li %r11, 0\n" +" lvx %v20, %r1, %r11\n" +" li %r11, 16\n" +" lvx %v21, %r1, %r11\n" +" li %r11, 32\n" +" lvx %v22, %r1, %r11\n" +" li %r11, 48\n" +" lvx %v23, %r1, %r11\n" +" li %r11, 64\n" +" lvx %v24, %r1, %r11\n" +" li %r11, 80\n" +" lvx %v25, %r1, %r11\n" +" li %r11, 96\n" +" lvx %v26, %r1, %r11\n" +" li %r11, 112\n" +" lvx %v27, %r1, %r11\n" +" li %r11, 128\n" +" lvx %v28, %r1, %r11\n" +" li %r11, 144\n" +" lvx %v29, %r1, %r11\n" +" li %r11, 160\n" +" lvx %v30, %r1, %r11\n" +" li %r11, 176\n" +" lvx %v31, %r1, %r11\n" +" ld %r0, 192(%r1)\n" +" mtspr 256, %r0\n" +#endif +" lfd %f0, 344(%r1)\n" +" mtfsf 0xff, %f0\n" +" lfd %f14, 200(%r1)\n" +" lfd %f15, 208(%r1)\n" +" lfd %f16, 216(%r1)\n" +" lfd %f17, 224(%r1)\n" +" lfd %f18, 232(%r1)\n" +" lfd %f19, 240(%r1)\n" +" lfd %f20, 248(%r1)\n" +" lfd %f21, 256(%r1)\n" +" lfd %f22, 264(%r1)\n" +" lfd %f23, 272(%r1)\n" +" lfd %f24, 280(%r1)\n" +" lfd %f25, 288(%r1)\n" +" lfd %f26, 296(%r1)\n" +" lfd %f27, 304(%r1)\n" +" lfd %f28, 312(%r1)\n" +" lfd %f29, 320(%r1)\n" +" lfd %f30, 328(%r1)\n" +" lfd %f31, 336(%r1)\n" +" ld %r14, 352(%r1)\n" +" ld %r15, 360(%r1)\n" +" ld %r16, 368(%r1)\n" +" ld %r17, 376(%r1)\n" +" ld %r18, 384(%r1)\n" +" ld %r19, 392(%r1)\n" +" ld %r20, 400(%r1)\n" +" ld %r21, 408(%r1)\n" +" ld %r22, 416(%r1)\n" +" ld %r23, 424(%r1)\n" +" ld %r24, 432(%r1)\n" +" ld %r25, 440(%r1)\n" +" ld %r26, 448(%r1)\n" +" ld %r27, 456(%r1)\n" +" ld %r28, 464(%r1)\n" +" ld %r29, 472(%r1)\n" +" ld %r30, 480(%r1)\n" +" ld %r31, 488(%r1)\n" +" # restore CR\n" +" ld %r0, 496(%r1)\n" +" mtcr %r0\n" +" # restore LR\n" +" ld %r0, 504(%r1)\n" +" mtlr %r0\n" +" # load PC into CTR (and R12 for the callee's TOC setup)\n" +" ld %r12, 512(%r1)\n" +" mtctr %r12\n" +" # adjust stack\n" +" addi %r1, %r1, 528\n" +" # use third arg as return value after jump\n" +" # and as first arg in context function\n" +" mr %r3, %r5\n" +" # jump to context\n" +" bctr\n" +".size bthread_jump_fcontext, .-bthread_jump_fcontext\n" +".section .note.GNU-stack,\"\",%progbits\n" +); + +#endif + +#if defined(BTHREAD_CONTEXT_PLATFORM_linux_ppc64) && defined(BTHREAD_CONTEXT_COMPILER_gcc) +__asm ( +".text\n" +".align 2\n" +".globl bthread_make_fcontext\n" +".type bthread_make_fcontext, @function\n" +"bthread_make_fcontext:\n" +" addis %r2, %r12, .TOC.-bthread_make_fcontext@ha\n" +" addi %r2, %r2, .TOC.-bthread_make_fcontext@l\n" +" .localentry bthread_make_fcontext, . - bthread_make_fcontext\n" +" # save return address into R6\n" +" mflr %r6\n" +" # first arg of bthread_make_fcontext() == top address of context-stack\n" +" # shift address in R3 to lower 16 byte boundary\n" +" clrrdi %r3, %r3, 4\n" +" # reserve space for context-data on context-stack\n" +" # including 64 byte of linkage + parameter area (R1 % 16 == 0)\n" +" subi %r3, %r3, 592\n" +" # third arg of bthread_make_fcontext() == address of context-function\n" +" # save address of context-function entry point\n" +" std %r5, 512(%r3)\n" +" # initial CR, FPSCR and VRSAVE of the context: the current ones\n" +" mfcr %r0\n" +" std %r0, 496(%r3)\n" +" mffs %f0\n" +" stfd %f0, 344(%r3)\n" +#ifdef __ALTIVEC__ +" mfspr %r0, 256\n" +" std %r0, 192(%r3)\n" +#endif +" # load LR\n" +" mflr %r0\n" +" # jump to label 1\n" +" bl 1f\n" +"1:\n" +" # load LR into R4\n" +" mflr %r4\n" +" # compute abs address of label finish\n" +" addi %r4, %r4, finish - 1b\n" +" # restore LR\n" +" mtlr %r0\n" +" # save address of finish as return-address for context-function\n" +" # will be entered after context-function returns\n" +" std %r4, 504(%r3)\n" +" # restore return address from R6\n" +" mtlr %r6\n" +" blr # return pointer to context-data\n" +"finish:\n" +" # save return address into R0\n" +" mflr %r0\n" Review Comment: Fixed in a8e33fae1685: `finish` now derives this module's TOC from LR (which holds the address of finish) before calling `_exit`. Checked by building the switch into a shared object and returning into it from a context function in the executable that uses the executable's TOC: the process exits with status 0, without the change the `_exit` call faults. bthread's task runner never returns, so this only matters for other users of the API. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
