search for: ftrace

...> When using -fPIE/PIC with function tracing, the compiler generates a > call through the GOT (call *__fentry__ at GOTPCREL). This instruction > takes 6 bytes instead of 5 on the usual relative call. > > If PIE is enabled, replace the 6th byte of the GOT call by a 1-byte nop > so ftrace can handle the previous 5-bytes as before. > > Position Independent Executable (PIE) support will allow to extended the > KASLR randomization range below the -2G memory limit. > > Signed-off-by: Thomas Garnier <thgarnie at google.com> > --- > arch/x86/include/asm/ftrac...

...> When using -fPIE/PIC with function tracing, the compiler generates a > call through the GOT (call *__fentry__ at GOTPCREL). This instruction > takes 6 bytes instead of 5 on the usual relative call. > > If PIE is enabled, replace the 6th byte of the GOT call by a 1-byte nop > so ftrace can handle the previous 5-bytes as before. > > Position Independent Executable (PIE) support will allow to extended the > KASLR randomization range below the -2G memory limit. > > Signed-off-by: Thomas Garnier <thgarnie at google.com> > --- > arch/x86/include/asm/ftrac...

...the compiler generates a > > > call through the GOT (call *__fentry__ at GOTPCREL). This instruction > > > takes 6 bytes instead of 5 on the usual relative call. > > > > > > If PIE is enabled, replace the 6th byte of the GOT call by a 1-byte nop > > > so ftrace can handle the previous 5-bytes as before. > > > > > > Position Independent Executable (PIE) support will allow to extended the > > > KASLR randomization range below the -2G memory limit. > > > > > > Signed-off-by: Thomas Garnier <thgarnie at google.c...

When using -fPIE/PIC with function tracing, the compiler generates a call through the GOT (call *__fentry__ at GOTPCREL). This instruction takes 6 bytes instead of 5 on the usual relative call. If PIE is enabled, replace the 6th byte of the GOT call by a 1-byte nop so ftrace can handle the previous 5-bytes as before. Position Independent Executable (PIE) support will allow to extended the KASLR randomization range below the -2G memory limit. Signed-off-by: Thomas Garnier <thgarnie at google.com> --- arch/x86/include/asm/ftrace.h | 6 +++-- arch/x86/include/...

When using -fPIE/PIC with function tracing, the compiler generates a call through the GOT (call *__fentry__ at GOTPCREL). This instruction takes 6 bytes instead of 5 on the usual relative call. If PIE is enabled, replace the 6th byte of the GOT call by a 1-byte nop so ftrace can handle the previous 5-bytes as before. Position Independent Executable (PIE) support will allow to extended the KASLR randomization range below the -2G memory limit. Signed-off-by: Thomas Garnier <thgarnie at google.com> --- arch/x86/include/asm/ftrace.h | 6 +++-- arch/x86/include/...

...with function tracing, the compiler generates a > > call through the GOT (call *__fentry__ at GOTPCREL). This instruction > > takes 6 bytes instead of 5 on the usual relative call. > > > > If PIE is enabled, replace the 6th byte of the GOT call by a 1-byte nop > > so ftrace can handle the previous 5-bytes as before. > > > > Position Independent Executable (PIE) support will allow to extended the > > KASLR randomization range below the -2G memory limit. > > > > Signed-off-by: Thomas Garnier <thgarnie at google.com> > > --- &g...

...taking this series through your tree? Acked-by: Michael S. Tsirkin <mst at redhat.com> if you want the virtio patches through my tree after all, let me know. > --- > The canonical location for the tracefs filesystem is at /sys/kernel/tracing. > > But, from Documentation/trace/ftrace.rst: > > Before 4.1, all ftrace tracing control files were within the debugfs > file system, which is typically located at /sys/kernel/debug/tracing. > For backward compatibility, when mounting the debugfs file system, > the tracefs file system will be automatically mounted...

...generates a >> call through the GOT (call *__fentry__ at GOTPCREL). This instruction >> takes 6 bytes instead of 5 on the usual relative call. >> >> With this change, function tracing supports 6 bytes on traceable >> function and can still replace relative calls on the ftrace assembly >> functions. >> >> Position Independent Executable (PIE) support will allow to extended the >> KASLR randomization range below the -2G memory limit. > > Question: This 6 bytes is only the initial call that gcc creates. When > function tracing is enabled, t...

...generates a >> call through the GOT (call *__fentry__ at GOTPCREL). This instruction >> takes 6 bytes instead of 5 on the usual relative call. >> >> With this change, function tracing supports 6 bytes on traceable >> function and can still replace relative calls on the ftrace assembly >> functions. >> >> Position Independent Executable (PIE) support will allow to extended the >> KASLR randomization range below the -2G memory limit. > > Question: This 6 bytes is only the initial call that gcc creates. When > function tracing is enabled, t...

...PIE/PIC with function tracing, the compiler generates a call through the GOT (call *__fentry__ at GOTPCREL). This instruction takes 6 bytes instead of 5 on the usual relative call. With this change, function tracing supports 6 bytes on traceable function and can still replace relative calls on the ftrace assembly functions. Position Independent Executable (PIE) support will allow to extended the KASLR randomization range below the -2G memory limit. Signed-off-by: Thomas Garnier <thgarnie at google.com> --- arch/x86/include/asm/ftrace.h | 23 +++++- arch/x86/include/asm/sections.h | 4...

...cing, the compiler generates a > call through the GOT (call *__fentry__ at GOTPCREL). This instruction > takes 6 bytes instead of 5 on the usual relative call. > > With this change, function tracing supports 6 bytes on traceable > function and can still replace relative calls on the ftrace assembly > functions. > > Position Independent Executable (PIE) support will allow to extended the > KASLR randomization range below the -2G memory limit. Question: This 6 bytes is only the initial call that gcc creates. When function tracing is enabled, the calls are back to the norm...

...call through the GOT (call *__fentry__ at GOTPCREL). This instruction > >> takes 6 bytes instead of 5 on the usual relative call. > >> > >> With this change, function tracing supports 6 bytes on traceable > >> function and can still replace relative calls on the ftrace assembly > >> functions. > >> > >> Position Independent Executable (PIE) support will allow to extended the > >> KASLR randomization range below the -2G memory limit. > > > > Question: This 6 bytes is only the initial call that gcc creates. When &gt...

At the most recent Xen Summit, Thomas Friebel presented a paper ("Preventing Guests from Spinning Around", http://xen.org/files/xensummitboston08/LHP.pdf) investigating the interactions between spinlocks and virtual machines. Specifically, he looked at what happens when a lock-holding VCPU gets involuntarily preempted. The obvious first order effect is that while the VCPU is not

At the most recent Xen Summit, Thomas Friebel presented a paper ("Preventing Guests from Spinning Around", http://xen.org/files/xensummitboston08/LHP.pdf) investigating the interactions between spinlocks and virtual machines. Specifically, he looked at what happens when a lock-holding VCPU gets involuntarily preempted. The obvious first order effect is that while the VCPU is not

At the most recent Xen Summit, Thomas Friebel presented a paper ("Preventing Guests from Spinning Around", http://xen.org/files/xensummitboston08/LHP.pdf) investigating the interactions between spinlocks and virtual machines. Specifically, he looked at what happens when a lock-holding VCPU gets involuntarily preempted. The obvious first order effect is that while the VCPU is not

...test changes in jump tables and crypto. - Fix wording on couple commits. - Revisit checkpatch warnings. - Moving to @chromium.org. - patch v5: - Adapt new crypto modules for PIE. - Improve per-cpu commit message. - Fix xen 32-bit build error with .quad. - Remove extra code for ftrace. - patch v4: - Simplify early boot by removing global variables. - Modify the mcount location script for __mcount_loc intead of the address read in the ftrace implementation. - Edit commit description to explain better where the kernel can be located. - Streamlined the testing don...

...test changes in jump tables and crypto. - Fix wording on couple commits. - Revisit checkpatch warnings. - Moving to @chromium.org. - patch v5: - Adapt new crypto modules for PIE. - Improve per-cpu commit message. - Fix xen 32-bit build error with .quad. - Remove extra code for ftrace. - patch v4: - Simplify early boot by removing global variables. - Modify the mcount location script for __mcount_loc intead of the address read in the ftrace implementation. - Edit commit description to explain better where the kernel can be located. - Streamlined the testing don...

...easy to reproduce, then it will cost a > lot of time to get the trace information again. > > So I think it is essential to add supporting for record the trace > information automatically in libvirt to satisfy the user's requirement. > That's why I'm currently implementing ftrace support in libvirt. > > How do you think about my idea? Any comment will be appreciated! > How hard/painless it would be to implement it? And, can you have both and then select which one to use? > Thanks, > Yu > > -- > libvir-list mailing list > libvir-list at redh...

During my compaction-related stuff, I encountered a bug with ballooning. With repeated inflating and deflating cycle, guest memory( ie, cat /proc/meminfo | grep MemTotal) is decreased and couldn't be recovered. The reason is balloon_lock doesn't cover release_pages_balloon so struct virtio_balloon fields could be overwritten by race of fill_balloon(e,g, vb->*pfns could be critical).

During my compaction-related stuff, I encountered a bug with ballooning. With repeated inflating and deflating cycle, guest memory( ie, cat /proc/meminfo | grep MemTotal) is decreased and couldn't be recovered. The reason is balloon_lock doesn't cover release_pages_balloon so struct virtio_balloon fields could be overwritten by race of fill_balloon(e,g, vb->*pfns could be critical).