On 09/27/2018 12:39 PM, Mathieu Desnoyers wrote: > On x86-64, the parametrized selftest code for rseq crashes with a > segmentation fault when compiled with -fpie. This happens when the > param_test binary is loaded at an address beyond 32-bit on x86-64. > > The issue is caused by use of a 32-bit register to hold the address > of the loop counter variable. > > Fix this by using a 64-bit register to calculate the address of the > loop counter variables as an offset from rip. > > Signed-off-by: Mathieu Desnoyers <[email protected]> > Acked-by: "Paul E . McKenney" <[email protected]> > Cc: <[email protected]> # v4.18 > Cc: Shuah Khan <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Joel Fernandes <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Catalin Marinas <[email protected]> > Cc: Dave Watson <[email protected]> > Cc: Will Deacon <[email protected]> > Cc: Andi Kleen <[email protected]> > Cc: [email protected] > Cc: "H . Peter Anvin" <[email protected]> > Cc: Chris Lameter <[email protected]> > Cc: Russell King <[email protected]> > Cc: Michael Kerrisk <[email protected]> > Cc: "Paul E . McKenney" <[email protected]> > Cc: Paul Turner <[email protected]> > Cc: Boqun Feng <[email protected]> > Cc: Josh Triplett <[email protected]> > Cc: Steven Rostedt <[email protected]> > Cc: Ben Maurer <[email protected]> > Cc: Andy Lutomirski <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Linus Torvalds <[email protected]> > --- > Changes since v1: > - Update email address for Shuah Khan based on updated MAINTAINERS > email address, > - Rebase on v4.19-rc5. > --- > tools/testing/selftests/rseq/param_test.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/tools/testing/selftests/rseq/param_test.c > b/tools/testing/selftests/rseq/param_test.c > index 642d4e12abea..eec2663261f2 100644 > --- a/tools/testing/selftests/rseq/param_test.c > +++ b/tools/testing/selftests/rseq/param_test.c > @@ -56,15 +56,13 @@ unsigned int yield_mod_cnt, nr_abort; > printf(fmt, ## __VA_ARGS__); \ > } while (0) > > -#if defined(__x86_64__) || defined(__i386__) > +#ifdef __i386__ > > #define INJECT_ASM_REG "eax" > > #define RSEQ_INJECT_CLOBBER \ > , INJECT_ASM_REG > > -#ifdef __i386__ > - > #define RSEQ_INJECT_ASM(n) \ > "mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \ > "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \ > @@ -76,9 +74,16 @@ unsigned int yield_mod_cnt, nr_abort; > > #elif defined(__x86_64__) > > +#define INJECT_ASM_REG_P "rax" > +#define INJECT_ASM_REG "eax" > + > +#define RSEQ_INJECT_CLOBBER \ > + , INJECT_ASM_REG_P \ > + , INJECT_ASM_REG > + > #define RSEQ_INJECT_ASM(n) \ > - "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG "\n\t" \ > - "mov (%%" INJECT_ASM_REG "), %%" INJECT_ASM_REG "\n\t" \ > + "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \ > + "mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \ > "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \ > "jz 333f\n\t" \ > "222:\n\t" \ > @@ -86,10 +91,6 @@ unsigned int yield_mod_cnt, nr_abort; > "jnz 222b\n\t" \ > "333:\n\t" > > -#else > -#error "Unsupported architecture" > -#endif > - > #elif defined(__s390__) > > #define RSEQ_INJECT_INPUT \ >
Applied now to linux-kselftest fixes. I will get this into the next rc thanks, -- Shuah
