riscv: handle kernel PTE edge-case in pmap_enter_l2()
ClosedPublic
Actions

Authored by mhorne on Oct 5 2022, 4:24 PM.

Details

Reviewers

markj
alc

Commits

rGce82d6846bda: riscv: handle kernel PTE edge-case in pmap_enter_l2()
rG1f9cc5ffc505: riscv: handle kernel PTE edge-case in pmap_enter_l2()

Summary

Page table pages are never freed from the kernel pmap, instead they are
zeroed when a range is unmapped. This allows future mappings to be
constructed more quickly. Detect this scenario in pmap_enter_l2(), so we
don't fail to create a superpage mapping when the 2MB range is actually
available.

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Passed

Unit

No Test Coverage

Build Status

Buildable 47698
Build 44585: arc lint + arc unit

Event Timeline

mhorne created this revision.Oct 5 2022, 4:24 PM

Herald added a subscriber: imp. · View Herald TranscriptOct 5 2022, 4:24 PM

mhorne requested review of this revision.Oct 5 2022, 4:24 PM

Harbormaster completed remote builds in B47698: Diff 111467.Oct 5 2022, 4:24 PM

mhorne mentioned this in D36563: riscv: handle existing mapping in pmap_enter_l2().Oct 5 2022, 4:25 PM

markj accepted this revision.Oct 5 2022, 4:28 PM

This revision is now accepted and ready to land.Oct 5 2022, 4:28 PM

alc added inline comments.Oct 5 2022, 4:40 PM

sys/riscv/riscv/pmap.c
3206	On amd64 and arm64, we don't maintain an exact count of the valid mappings within a kernel page table page. If that is true on riscv, then this section of code should look more like the amd64 and arm64 versions.

mhorne marked an inline comment as done.Oct 5 2022, 4:58 PM

mhorne added inline comments.

sys/riscv/riscv/pmap.c
3206	Yes, good catch. I will make the adjustment as part of D36563.

Closed by commit rG1f9cc5ffc505: riscv: handle kernel PTE edge-case in pmap_enter_l2() (authored by mhorne). · Explain WhyOct 6 2022, 10:08 PM

This revision was automatically updated to reflect the committed changes.

mhorne marked an inline comment as done.

mhorne added a commit: rG1f9cc5ffc505: riscv: handle kernel PTE edge-case in pmap_enter_l2().

mhorne added a commit: rGce82d6846bda: riscv: handle kernel PTE edge-case in pmap_enter_l2().Oct 13 2022, 2:10 PM

Revision Contents
Changeset List

Path

Size

sys/

riscv/

pmap.c

21 lines

Diff 111467

View Options

sys/riscv/riscv/pmap.c

	Show All 22 Lines

	#ifdef __linux			#ifdef __linux
	# include <sys/syscall.h>			# include <sys/syscall.h>
	# ifdef DEVRANDOM_WAIT			# ifdef DEVRANDOM_WAIT
	# include <sys/shm.h>			# include <sys/shm.h>
	# include <sys/utsname.h>			# include <sys/utsname.h>
	# endif			# endif
	#endif			#endif
	#if (defined(__FreeBSD__) \|\| defined(__NetBSD__)) && !defined(OPENSSL_SYS_UEFI)			#if defined(__NetBSD__) && !defined(OPENSSL_SYS_UEFI)
	# include <sys/types.h>			# include <sys/types.h>
	# include <sys/sysctl.h>			# include <sys/sysctl.h>
	# include <sys/param.h>			# include <sys/param.h>
	#endif			#endif
	#if defined(__OpenBSD__)			#if defined(__OpenBSD__)
	# include <sys/param.h>			# include <sys/param.h>
	#endif			#endif
	#if defined(__DragonFly__)			#if defined(__DragonFly__) \|\| defined(__FreeBSD__)
	# include <sys/param.h>			# include <sys/param.h>
	# include <sys/random.h>			# include <sys/random.h>
	#endif			#endif

	#if (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS)) \			#if (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS)) \
	\|\| defined(__DJGPP__)			\|\| defined(__DJGPP__)
	# include <sys/types.h>			# include <sys/types.h>
	# include <sys/stat.h>			# include <sys/stat.h>
	▲ Show 20 Lines • Show All 159 Lines • ▼ Show 20 Lines
	# define OPENSSL_RAND_SEED_GETRANDOM			# define OPENSSL_RAND_SEED_GETRANDOM
	# define OPENSSL_RAND_SEED_DEVRANDOM			# define OPENSSL_RAND_SEED_DEVRANDOM
	# endif			# endif

	# if defined(OPENSSL_RAND_SEED_LIBRANDOM)			# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
	# error "librandom not (yet) supported"			# error "librandom not (yet) supported"
	# endif			# endif

	# if (defined(__FreeBSD__) \|\| defined(__NetBSD__)) && defined(KERN_ARND)			# if defined(__NetBSD__) && defined(KERN_ARND)
	/*			/*
	* sysctl_random(): Use sysctl() to read a random number from the kernel			* sysctl_random(): Use sysctl() to read a random number from the kernel
	* Returns the number of bytes returned in buf on success, -1 on failure.			* Returns the number of bytes returned in buf on success, -1 on failure.
	*/			*/
	static ssize_t sysctl_random(char *buf, size_t buflen)			static ssize_t sysctl_random(char *buf, size_t buflen)
	{			{
	int mib[2];			int mib[2];
	size_t done = 0;			size_t done = 0;
	▲ Show 20 Lines • Show All 660 Lines • Show Last 20 Lines

riscv: handle kernel PTE edge-case in pmap_enter_l2()ClosedPublicActions