pkubaj commented on code in PR #3696: URL: https://github.com/apache/brpc/pull/3696#discussion_r4440491335
########## 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" Review Comment: Fixed in a8e33fae1685: `bthread_make_fcontext` zeroes the back chain of the context's first frame, as boost.context does. Added `stack_walk_of_new_context_terminates`, which walks the back chains from inside a new context on a stack filled with 0xa5 and expects the walk to end on a zero word without leaving the stack; it fails without the store. -- 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]
