Bug 68661
| Summary: | xprtrdma: allocates a 1024 bytes array on the stack | ||
|---|---|---|---|
| Product: | File System | Reporter: | Paul Bolle (pebolle) |
| Component: | NFS | Assignee: | Chuck Lever (chucklever) |
| Status: | RESOLVED CODE_FIX | ||
| Severity: | normal | CC: | trondmy |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | v3.13-rc8 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: | Paul Bolle's proposed fix | ||
This issue will be addressed when we do a major overhaul to get large arrays off the stack. It is in plan for this year. [cel@manet linux-2.6]$ ARCH=x86_64 make checkstack | grep xprtrdma 0x0000331d rpcrdma_register_default_external [xprtrdma]:1064 0x00003421 rpcrdma_register_default_external [xprtrdma]:1064 0x000029cd rpcrdma_register_fmr_external [xprtrdma]: 568 0x00002b07 rpcrdma_register_fmr_external [xprtrdma]: 568 0x000040e4 rpcrdma_conn_upcall [xprtrdma]: 304 0x00002ced rpcrdma_register_frmr_external [xprtrdma]: 264 0x00002f33 rpcrdma_register_frmr_external [xprtrdma]: 264 0x00003d34 rpcrdma_ep_connect [xprtrdma]: 240 0x00000954 xprt_setup_rdma [xprtrdma]: 208 0x00004564 rpcrdma_ep_create [xprtrdma]: 208 0x000049b4 rpcrdma_ia_open [xprtrdma]: 208 0x00005964 rpcrdma_ep_post [xprtrdma]: 144 0x00005bfd rpcrdma_cq_event_upcall [xprtrdma]: 136 0x00005d7d rpcrdma_cq_event_upcall [xprtrdma]: 136 0x00002c0b rpcrdma_deregister_frmr_external [xprtrdma]: 112 0x00002cb4 rpcrdma_deregister_frmr_external [xprtrdma]: 112 0x00001e2d rpcrdma_create_chunks [xprtrdma]: 104 0x00001f7e rpcrdma_create_chunks [xprtrdma]: 104 0x0000214a rpcrdma_create_chunks [xprtrdma]: 104 [cel@manet linux-2.6]$ head Makefile VERSION = 3 PATCHLEVEL = 13 SUBLEVEL = 0 EXTRAVERSION = NAME = One Giant Leap for Frogkind # *DOCUMENTATION* # To see a list of typical targets execute "make help" # More info can be located in ./README # Comments in this file are targeted only to the developer, do not [cel@manet linux-2.6]$ Created attachment 123111 [details]
Paul Bolle's proposed fix
Attaching Paul's original fix, for reference.
(In reply to Paul Bolle from comment #0) > 0) Building verbs.o on 32 bits x86, with CONFIG_FRAME_WARN set to 1024, its > default value, triggers this GCC warning: > net/sunrpc/xprtrdma/verbs.c: In function > ‘rpcrdma_register_default_external’: > net/sunrpc/xprtrdma/verbs.c:1774:1: warning: the frame size of 1040 > bytes is larger than 1024 bytes [-Wframe-larger-than=] > > That warning can be seen for (quite) a number of releases now (at leats > since v3.8). > v3.16-rc1 shipped with commit 0ac531c18323 ("xprtrdma: Remove REGISTER memory registration mode"). That commit removed rpcrdma_register_default_external(). That made this warning go away, obviously. It didn't introduce another warning, so verbs.o now builds silent again. That is good. It is also all I care about, but there may be a reason to keep this bug open. That's up to Chuck to decide. |
0) Building verbs.o on 32 bits x86, with CONFIG_FRAME_WARN set to 1024, its default value, triggers this GCC warning: net/sunrpc/xprtrdma/verbs.c: In function ‘rpcrdma_register_default_external’: net/sunrpc/xprtrdma/verbs.c:1774:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=] That warning can be seen for (quite) a number of releases now (at leats since v3.8). 1) This warning should be silenced by allocating "ipb" dynamically, but a patch to do that apparently requires more than trivial understanding of NFS. Since I lack such understanding, my straightforward patch to allocate that array on the heap was insufficient (see https://lkml.org/lkml/2014/1/13/325). 2) Note that discussion of that patch also uncovered that xprt_rdma_send_request() will currently fail, if we return an error from rpcrdma_register_default_external().