svn commit: r191973 - in head/sys: amd64/linux32 compat/linux i386/linux

[Dmitry Chagin]

Author: dchagin
Date: Sun May 10 18:43:43 2009
New Revision: 191973
URL: http://svn.freebsd.org/changeset/base/191973

Log:
  Do not export AT_CLKTCK when emulating Linux kernel prior
  to 2.4.0, as it has appeared in the 2.4.0-rc7 first time.
  Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
  glibc falls back to the hard-coded CLK_TCK value when aux entry
  is not present.
  
  Glibc versions prior to 2.2.1 always use hard-coded CLK_TCK value.
  
  For older applications/libc's which depends on hard-coded CLK_TCK
  value user should set compat.linux.osrelease less than 2.4.0.
  
  Approved by:	kib (mentor)

Modified:
  head/sys/amd64/linux32/linux32_sysvec.c
  head/sys/compat/linux/linux_mib.h
  head/sys/compat/linux/linux_misc.c
  head/sys/i386/linux/linux_sysvec.c

Modified: head/sys/amd64/linux32/linux32_sysvec.c
==============================================================================
--- head/sys/amd64/linux32/linux32_sysvec.c	Sun May 10 18:27:20 2009	(r191972)
+++ head/sys/amd64/linux32/linux32_sysvec.c	Sun May 10 18:43:43 2009	(r191973)
@@ -261,7 +261,17 @@ elf_linux_fixup(register_t **stack_base,
 	pos = base + (imgp->args->argc + imgp->args->envc + 2);
 
 	AUXARGS_ENTRY_32(pos, LINUX_AT_HWCAP, cpu_feature);
-	AUXARGS_ENTRY_32(pos, LINUX_AT_CLKTCK, stclohz);
+
+	/*
+	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
+	 * as it has appeared in the 2.4.0-rc7 first time.
+	 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
+	 * glibc falls back to the hard-coded CLK_TCK value when aux entry
+	 * is not present.
+	 * Also see linux_times() implementation.
+	 */
+	if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
+		AUXARGS_ENTRY_32(pos, LINUX_AT_CLKTCK, stclohz);
 	AUXARGS_ENTRY_32(pos, AT_PHDR, args->phdr);
 	AUXARGS_ENTRY_32(pos, AT_PHENT, args->phent);
 	AUXARGS_ENTRY_32(pos, AT_PHNUM, args->phnum);

Modified: head/sys/compat/linux/linux_mib.h
==============================================================================
--- head/sys/compat/linux/linux_mib.h	Sun May 10 18:27:20 2009	(r191972)
+++ head/sys/compat/linux/linux_mib.h	Sun May 10 18:43:43 2009	(r191973)
@@ -45,6 +45,7 @@ int	linux_set_oss_version(struct thread 
 
 int	linux_kernver(struct thread *td);
 
+#define	LINUX_KERNVER_2004000		2004000
 #define	LINUX_KERNVER_2006000		2006000
 
 #define	linux_use26(t)		(linux_kernver(t) >= LINUX_KERNVER_2006000)

Modified: head/sys/compat/linux/linux_misc.c
==============================================================================
--- head/sys/compat/linux/linux_misc.c	Sun May 10 18:27:20 2009	(r191972)
+++ head/sys/compat/linux/linux_misc.c	Sun May 10 18:43:43 2009	(r191973)
@@ -661,7 +661,19 @@ struct l_times_argv {
 	l_clock_t	tms_cstime;
 };
 
-#define CONVTCK(r)	(r.tv_sec * stclohz + r.tv_usec / (1000000 / stclohz))
+
+/*
+ * Glibc versions prior to 2.2.1 always use hard-coded CLK_TCK value.
+ * Since 2.2.1 Glibc uses value exported from kernel via AT_CLKTCK
+ * auxiliary vector entry.
+ */
+#define	CLK_TCK		100
+
+#define	CONVOTCK(r)	(r.tv_sec * CLK_TCK + r.tv_usec / (1000000 / CLK_TCK))
+#define	CONVNTCK(r)	(r.tv_sec * stclohz + r.tv_usec / (1000000 / stclohz))
+
+#define	CONVTCK(r)	(linux_kernver(td) >= LINUX_KERNVER_2004000 ?		\
+			    CONVNTCK(r) : CONVOTCK(r))
 
 int
 linux_times(struct thread *td, struct linux_times_args *args)

Modified: head/sys/i386/linux/linux_sysvec.c
==============================================================================
--- head/sys/i386/linux/linux_sysvec.c	Sun May 10 18:27:20 2009	(r191972)
+++ head/sys/i386/linux/linux_sysvec.c	Sun May 10 18:43:43 2009	(r191973)
@@ -255,7 +255,17 @@ elf_linux_fixup(register_t **stack_base,
 	pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
 
 	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
-	AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
+
+	/*
+	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
+	 * as it has appeared in the 2.4.0-rc7 first time.
+	 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
+	 * glibc falls back to the hard-coded CLK_TCK value when aux entry
+	 * is not present.
+	 * Also see linux_times() implementation.
+	 */
+	if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
+		AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);