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So use it. >>> >>> Signed-off-by: Eugene Loh >> Reviewed-by: Kris Van Hees > Still applies but see below... > >>> --- >>> libdtrace/dt_prov_uprobe.c | 21 +++++++-------------- >>> 1 file changed, 7 insertions(+), 14 deletions(-) >>> >>> diff --git a/libdtrace/dt_prov_uprobe.c b/libdtrace/dt_prov_uprobe.c >>> index 5d9f74244..f1323cc31 100644 >>> --- a/libdtrace/dt_prov_uprobe.c >>> +++ b/libdtrace/dt_prov_uprobe.c >>> @@ -1015,22 +1015,15 @@ static int trampoline(dt_pcb_t *pcb, uint_t exitlbl) >>> emit(dlp, BPF_ALU64_IMM(BPF_RSH, BPF_REG_0, 32)); >>> >>> /* >>> - * Look up in the BPF 'usdt_prids' map. Space for the look-up key >>> - * will be used on the BPF stack: >>> - * >>> - * offset value >>> - * >>> - * -sizeof(usdt_prids_map_key_t) pid (in %r0) >>> - * >>> - * -sizeof(usdt_prids_map_key_t) + sizeof(pid_t) >>> - * == >>> - * -sizeof(dtrace_id_t) underlying-probe prid >>> + * Look up in the BPF 'usdt_prids' map. The key should fit into >>> + * trampoline stack slot 0. >>> */ >>> - emit(dlp, BPF_STORE(BPF_W, BPF_REG_9, (int)(-sizeof(usdt_prids_map_key_t)), BPF_REG_0)); >>> - emit(dlp, BPF_STORE_IMM(BPF_W, BPF_REG_9, (int)(-sizeof(dtrace_id_t)), uprp->desc->id)); >>> + assert(sizeof(usdt_prids_map_key_t) <= DT_STK_SLOT_SZ); >>> + emit(dlp, BPF_STORE(BPF_W, BPF_REG_FP, DT_TRAMP_SP_SLOT(0), BPF_REG_0)); >>> + emit(dlp, BPF_STORE_IMM(BPF_W, BPF_REG_FP, DT_TRAMP_SP_SLOT(0) + sizeof(pid_t), uprp->desc->id)); > I get a compiler warning here: > > libdtrace/dt_prov_uprobe.c: In function â?~trampolineâ?T: > include/bpf_asm.h:119:24: warning: overflow in conversion from â?~long unsigned intâ?T to â?~short intâ?T changes value from â?~18446744073709551524â?T to â?~-92â?T [-Woverflo] > 119 | .off = (ofs), \ > | ^ > libdtrace/dt_as.h:42:69: note: in definition of macro â?~emitleâ?T > 42 | dt_irnode_t *dip = dt_cg_node_alloc((lbl), (instr)); \ > | ^~~~~ > > libdtrace/dt_prov_uprobe.c:1013:9: note: in expansion of macro â?~emitâ?T > 1013 | emit(dlp, BPF_STORE_IMM(BPF_W, BPF_REG_FP, DT_TRAMP_SP_SLOT(0) + sizeof(pid_t), uprp->desc->id)); > | ^~~~ > libdtrace/dt_prov_uprobe.c:1013:20: note: in expansion of macro â?~BPF_STORE_IMMâ?T > 1013 | emit(dlp, BPF_STORE_IMM(BPF_W, BPF_REG_FP, DT_TRAMP_SP_SLOT(0) + sizeof(pid_t), uprp->desc->id)); > > You need a (int) cast for sizeof(pid_t) similar to the casts that were in > the code before. I'll add it in as I merge. Thanks.  Might this correction already be in the 2/2 patch?  (Not that that's the right place for it, but...) >>> dt_cg_xsetx(dlp, usdt_prids, DT_LBL_NONE, BPF_REG_1, usdt_prids->di_id); >>> - emit(dlp, BPF_MOV_REG(BPF_REG_2, BPF_REG_9)); >>> - emit(dlp, BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, (int)(-sizeof(usdt_prids_map_key_t)))); >>> + emit(dlp, BPF_MOV_REG(BPF_REG_2, BPF_REG_FP)); >>> + emit(dlp, BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, DT_TRAMP_SP_SLOT(0))); >>> emit(dlp, BPF_CALL_HELPER(BPF_FUNC_map_lookup_elem)); >>> emit(dlp, BPF_BRANCH_IMM(BPF_JEQ, BPF_REG_0, 0, lbl_exit)); >>> >>> -- >>> 2.43.5 >>> >>> >> _______________________________________________ >> DTrace-devel mailing list >> DTrace-devel@oss.oracle.com >> https://oss.oracle.com/mailman/listinfo/dtrace-devel