Le 05/09/2024 à 18:13, Jason A. Donenfeld a écrit :
+/*
+ * The macro sets two stack frames, one for the caller and one for the callee
+ * because there are no requirement for the caller to set a stack frame when
+ * calling VDSO so it may have omitted to set one, especially on PPC64
+ */
+
+.macro cvdso_call funct
+ .cfi_startproc
+ PPC_STLU r1, -PPC_MIN_STKFRM(r1)
+ .cfi_adjust_cfa_offset PPC_MIN_STKFRM
+ mflr r0
+ PPC_STLU r1, -PPC_MIN_STKFRM(r1)
+ .cfi_adjust_cfa_offset PPC_MIN_STKFRM
+ PPC_STL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
+ .cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF
+ get_datapage r8
+ addi r8, r8, VDSO_RNG_DATA_OFFSET
+ bl CFUNC(DOTSYM(\funct))
+ PPC_LL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
+ cmpwi r3, 0
+ mtlr r0
+ addi r1, r1, 2 * PPC_MIN_STKFRM
+ .cfi_restore lr
+ .cfi_def_cfa_offset 0
+ crclr so
+ bgelr+
+ crset so
+ neg r3, r3
+ blr
+ .cfi_endproc
+.endm
You wrote in an earlier email that this worked with time namespaces, but
in my testing that doesn't seem to be the case.
Did I write that ? I can't remember and neither can I remember testing
it with time namespaces.
From my test harness [1]:
Normal single thread
vdso: 25000000 times in 12.494133131 seconds
libc: 25000000 times in 69.594625188 seconds
syscall: 25000000 times in 67.349243972 seconds
Time namespace single thread
vdso: 25000000 times in 71.673057436 seconds
libc: 25000000 times in 71.712774121 seconds
syscall: 25000000 times in 66.902318080 seconds
I'm seeing this on ppc, ppc64, and ppc64le.
What is the command to use to test with time namespace ?
Can you figure out what's going on and send a fix, which I'll squash
into this commit?
Sure
Jason
[1] https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.zx2c4.com%2Flinux-rng%2Fcommit%2F%3Fh%3Djd%2Fvdso-test-harness&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C59fa9061064945c73a1608dccdc5b51c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638611496253413014%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=ZUJqhcnZL7SYkuXUIt9Nlo46sZj26VYW%2F8I%2BrBLRpBE%3D&reserved=0
