| Message ID | 20190717080621.40424-10-yanaijie@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implement KASLR for powerpc/fsl_booke/32 | expand |
Le 17/07/2019 à 10:06, Jason Yan a écrit : > One may want to disable kaslr when boot, so provide a cmdline parameter > 'nokaslr' to support this. > > Signed-off-by: Jason Yan <yanaijie@huawei.com> > Cc: Diana Craciun <diana.craciun@nxp.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Christophe Leroy <christophe.leroy@c-s.fr> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Nicholas Piggin <npiggin@gmail.com> > Cc: Kees Cook <keescook@chromium.org> > --- > arch/powerpc/kernel/kaslr_booke.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c > index 00339c05879f..e65a5d9d2ff1 100644 > --- a/arch/powerpc/kernel/kaslr_booke.c > +++ b/arch/powerpc/kernel/kaslr_booke.c > @@ -373,6 +373,18 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size > return kaslr_offset; > } > > +static inline __init bool kaslr_disabled(void) > +{ > + char *str; > + > + str = strstr(early_command_line, "nokaslr"); Why using early_command_line instead of boot_command_line ? > + if ((str == early_command_line) || > + (str > early_command_line && *(str - 1) == ' ')) Is that stuff really needed ? Why not just: return strstr(early_command_line, "nokaslr") != NULL; > + return true; > + > + return false; > +} > + > /* > * To see if we need to relocate the kernel to a random offset > * void *dt_ptr - address of the device tree > @@ -388,6 +400,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > kernel_sz = (unsigned long)_end - KERNELBASE; > > kaslr_get_cmdline(dt_ptr); > + if (kaslr_disabled()) > + return; > > offset = kaslr_choose_location(dt_ptr, size, kernel_sz); > > Christophe
On 2019/7/29 19:38, Christophe Leroy wrote: > > > Le 17/07/2019 à 10:06, Jason Yan a écrit : >> One may want to disable kaslr when boot, so provide a cmdline parameter >> 'nokaslr' to support this. >> >> Signed-off-by: Jason Yan <yanaijie@huawei.com> >> Cc: Diana Craciun <diana.craciun@nxp.com> >> Cc: Michael Ellerman <mpe@ellerman.id.au> >> Cc: Christophe Leroy <christophe.leroy@c-s.fr> >> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> >> Cc: Paul Mackerras <paulus@samba.org> >> Cc: Nicholas Piggin <npiggin@gmail.com> >> Cc: Kees Cook <keescook@chromium.org> >> --- >> arch/powerpc/kernel/kaslr_booke.c | 14 ++++++++++++++ >> 1 file changed, 14 insertions(+) >> >> diff --git a/arch/powerpc/kernel/kaslr_booke.c >> b/arch/powerpc/kernel/kaslr_booke.c >> index 00339c05879f..e65a5d9d2ff1 100644 >> --- a/arch/powerpc/kernel/kaslr_booke.c >> +++ b/arch/powerpc/kernel/kaslr_booke.c >> @@ -373,6 +373,18 @@ static unsigned long __init >> kaslr_choose_location(void *dt_ptr, phys_addr_t size >> return kaslr_offset; >> } >> +static inline __init bool kaslr_disabled(void) >> +{ >> + char *str; >> + >> + str = strstr(early_command_line, "nokaslr"); > > Why using early_command_line instead of boot_command_line ? > Will switch to boot_command_line. > >> + if ((str == early_command_line) || >> + (str > early_command_line && *(str - 1) == ' ')) > > Is that stuff really needed ? > > Why not just: > > return strstr(early_command_line, "nokaslr") != NULL; > This code is derived from other arch such as arm64/mips. It's trying to make sure that 'nokaslr' is a separate word but not part of other words such as 'abcnokaslr'. >> + return true; >> + >> + return false; >> +} > > >> + >> /* >> * To see if we need to relocate the kernel to a random offset >> * void *dt_ptr - address of the device tree >> @@ -388,6 +400,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, >> phys_addr_t size) >> kernel_sz = (unsigned long)_end - KERNELBASE; >> kaslr_get_cmdline(dt_ptr); >> + if (kaslr_disabled()) >> + return; >> offset = kaslr_choose_location(dt_ptr, size, kernel_sz); >> > > Christophe > > . >
diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c index 00339c05879f..e65a5d9d2ff1 100644 --- a/arch/powerpc/kernel/kaslr_booke.c +++ b/arch/powerpc/kernel/kaslr_booke.c @@ -373,6 +373,18 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size return kaslr_offset; } +static inline __init bool kaslr_disabled(void) +{ + char *str; + + str = strstr(early_command_line, "nokaslr"); + if ((str == early_command_line) || + (str > early_command_line && *(str - 1) == ' ')) + return true; + + return false; +} + /* * To see if we need to relocate the kernel to a random offset * void *dt_ptr - address of the device tree @@ -388,6 +400,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) kernel_sz = (unsigned long)_end - KERNELBASE; kaslr_get_cmdline(dt_ptr); + if (kaslr_disabled()) + return; offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
One may want to disable kaslr when boot, so provide a cmdline parameter 'nokaslr' to support this. Signed-off-by: Jason Yan <yanaijie@huawei.com> Cc: Diana Craciun <diana.craciun@nxp.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Kees Cook <keescook@chromium.org> --- arch/powerpc/kernel/kaslr_booke.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)